Nanomedicine: Nanotechnology, Biology and Medicine - Articles in Press

A Novel Therapeutic System for Malignant Glioma: Nanoformulation, Pharmacokinetic and Anti-Cancer Properties of Cell-Nano-Drug delivery - Accepted Manuscript

Youhua Tao, Miaomiao Ning, Huanyu Dou — 2012-02-02

Abstract: Macrophage carriage, release, and anti-tumor activities of polymeric nanoformulated paclitaxel (PTX) were developed as a novel delivery system for malignant glioma. To achieve this goal, we synthesized PTX-loaded nanoformulations (nano-PTX), then investigated their uptake, release and toxicologic properties. Chemosensitivity was significant in U87 cells (p<0.05) at concentrations from 10-4 to 10-8 M following 72 hrs exposure to bone marrow derived macrophages (BMM)-nano-PTX in comparison to treatment with nano-PTX alone. The most significant reductions in U87 cell viability (p<0.05) were observed in the transwell cocultures containing BMM-nano-PTX. Limited toxicity to BMM was observed at the same concentrations. BMM functions were tested by analysis of microtubules and actin filaments, as the cytoarchitecture, demonstrating a similar cytoskeleton pattern before and after nano-PTX loaded into cells. This data indicate that nanoformulations of PTX facilitate cell uptake, delay toxicity, and show improved therapeutic efficacy by BMM-nano-PTX delivery.Graphical Abstract: A novel anti-tumor drug nanoparticle (NP) was formulated for developing of cell-NP delivery system. NP are carried within bone-marrow-derived monocytes/macrophages (BMM) demonstrating extraordinary abilities to migrate across the BBB, infiltrate into tumor, and release the anti-tumor medicine.

Peptide PHSCNK as an integrin α5β1 antagonist targets stealth liposomes to integrin-overexpressing melanoma - Accepted Manuscript

2012-02-02

Abstract: As an integrin α5β1 antagonist, N-acetyl-proline-histidine-serine-cysteine-asparagine-amide (Ac-PHSCN-NH2) is currently in phase II trials for various cancer therapies. In the present work, Ac-PHSCNK-NH2 (PHSCNK) was used as a novel homing peptide to prepare ligand-targeted liposomes loaded with doxorubicin (PHSCNK-PL-DOX), with the hypothesis that the therapy target of integrin α5β1 may also be served as a delivery target. The stealth liposomes loaded with doxorubicin (PL-DOX) were used as the control. PHSCNK-PL-DOX demonstrated an enhanced intracellular uptake and a greater cytotoxicity against melanoma B16F10 cells compared with PL-DOX. The novel targeted formulation displayed stronger tumor inhibition and prolonged survival time compared with controls in C57BL/6 mice bearing B16F10 tumor, while it exhibited less heart toxicity in H&E staining of tissues. Taking the pharmacokinetics and biodistribution results into account, it is concluded that α5β1 integrin-mediated liposomes might be used as a potential delivery system for targeted tumor therapy.Graphical abstract: As an integrin α5β1 antagonist, N-acetyl-proline-histidine-serine-cysteine-asparagine-amide (Ac-PHSCN-NH2) is currently in phase II trials for various cancer therapies. In the present work, Ac-PHSCNK-NH2 (PHSCNK) was used as a novel homing peptide to prepare ligand-targeted liposomes loaded with doxorubicin (PHSCNK-PL-DOX), with the hypothesis that the therapy target of integrin α5β1 may also be served as a delivery target. The stealth liposomes loaded with doxorubicin (PL-DOX) were used as the control. PHSCNK-PL-DOX demonstrated an enhanced intracellular uptake and a greater cytotoxicity against melanoma B16F10 cells compared with PL-DOX. The novel targeted formulation displayed stronger tumor inhibition and prolonged survival time compared with controls in C57BL/6 mice bearing B16F10 tumor, while it exhibited less heart toxicity in H&E staining of tissues. Taking the pharmacokinetics and biodistribution results into account, it is concluded that α5β1 integrin-mediated liposomes might be used as a potential delivery system for targeted tumor therapy.

Mouse respiratory cilia with the asymmetric axonemal structure on sparsely distributed ciliary cells can generate overall directional flow - Accepted Manuscript

2012-02-02

Abstract: Mucociliary clearance on the surface of the tracheal lumen is an important component of lung defense against dust mites and viruses. However, the axonemal structure that achieves effective ciliary motion and the mechanisms by which discretely distributed ciliary cells generate directional flow are unknown. In this study, we examined individual ciliary motion with 7–9-nm spatial precision by labeling the ciliary tip with quantum dots, and detected an asymmetric beating pattern. Cryo-electron tomography revealed that the densities of two inner dynein arms were missing from at least two doublet microtubules in the axonemal structure. Although the flow directions generated by individual ciliated cells were unsteady and diverse, the time- and space-averaged velocity field was found to be directional. These results indicate that the asymmetric ciliary motion is driven by the asymmetric axonemal structure, and it generates overall directional flow from the lungs to the oropharynx on sparsely distributed ciliated cells.Graphical abstract: The fluid flow with effective ciliary motion on the surface of the tracheal lumen is an important part of lung defense against dust mites, viruses or other harmful substances. In this paper, we examined the axonemal structure by cryo-electron tomography. The densities of two inner dynein arm subspecies were missing from at least two doublet microtubules, indicating that the asymmetric axonemal structure contributes to asymmetric ciliary motion, generates overall directional flow from the lungs to the oropharynx in airway.

Quantitative molecular profiling of biomarkers for pancreatic cancer with functionalized quantum dots - Accepted Manuscript

2012-02-02

Abstract: Applications in nanomedicine, such as diagnostics and targeted therapeutics, rely on the detection and targeting of membrane biomarkers. In this paper we demonstrate absolute quantitative profiling, spatial mapping, and multiplexing of cancer biomarkers using functionalized quantum dots. We demonstrate highly selective targeting molecular markers for pancreatic cancer with extremely low levels of non-specific binding. We confirm that we have saturated all biomarkers on the cell surface, and, in conjunction with control experiments, extract absolute quantitative values for the biomarker density in terms of the number of molecules per square micrometer on the cell surface. We show that we can obtain quantitative spatial information of biomarker distribution on a single cell, important since tumors cell populations are inherently heterogeneous. We validate our quantitative measurements (number of molecules per square micron) using flow cytometry and demonstrate multiplexed quantitative profiling using color-coded quantum dots.Graphical abstract: Quantitative targeting of pancreatic cancer biomarkers is demonstrated using quantum dot - antibody conjugates. Profiling and spatial mapping at the single cell level can be are achieved through minimizing non-specific binding and aggregation.

Gene delivery nanoparticles specific for human microvasculature and macrovasculature - Accepted Manuscript

Ron B. Shmueli, Joel C. Sunshine, Zhenhua Xu, Elia J. Duh, Jordan J. Green — 2012-02-02

Abstract: Endothelial cell dysfunction is a critical component of ocular diseases such as age-related macular degeneration and diabetic retinopathy. An important limitation in endothelial cell research is the difficulty in achieving efficient transfection of these cells. A new polymer library was synthesized and utilized to find polymeric nanoparticles that can transfect macrovascular (human umbilical vein, HUVECs) and microvascular (human retinal, HRECs) endothelial cells. Nanoparticles were synthesized that can achieve transfection efficiency of up to 85% for HRECs and 65% for HUVECs.These nanoparticle systems enable high levels of expression while avoiding problems associated with viral gene delivery. The polymeric nanoparticles also show cell-specific behavior, with a high correlation between microvascular and macrovascular transfection (R2 = 0.81), but low correlation between retinal endothelial and retinal epithelial transfection (R2 = 0.21). These polymeric nanoparticles may be used in vitro as experimental tools and potentially in vivoto target and treat vascular-specific diseases.Graphical abstract: A class of polymers, poly(beta-amino esters), (PBAEs) was evaluated to find polymers that can transfect both microvascular (HREC) and macrovascular (HUVEC) cells. These polymers self-assemble with DNA to form nanoparticles (right). Certain PBAEs were able to transfect both of these types of cells with high efficiency (left), better than the leading commercially available reagents. Additionally, there is a strong correlation between the transfection profiles of these endothelial type cells (R2 = 0.81). This contrasts with a much lower correlation between the transfection profiles of the human retinal endothelial cells and human retinal pigment epithelial cells (R2 = 0.21).

Disassembly and reassembly improves morphology and thermal stability of human papillomavirus type 16 virus-like particles - Accepted Manuscript

2012-02-02

Abstract: Recombinant human papillomavirus (HPV) 16 L1 protein self-assembles into virus-like particles (VLPs) with diameters of 40 to 60 nm, which are key components in prophylactic HPV vaccines. Marked improvement in morphology and thermal stability upon VLP disassembly and reassembly was demonstrated at production scale. Differential scanning calorimetry showed enhanced conformational stability as indicated by the unfolding temperatures and peak heights/areas. Cloud point studies indicated (1) a much lower propensity for post-reassembly VLPs to aggregate during a time course study and (2) much higher cloud point temperatures. In-solution atomic force microscopy showed more uniform size distribution and fully closed particles, with evidence of virion-like assembly revealed by the structural details from a single particle image. Similar approaches for the reassembly of other recombinant VLPs with intrinsic conformational switches would be expected to improve the particle properties and render nanoparticles more suitable for use as vaccines or therapeutics. Graphical Abstract: In-solution AFM characterization of HPV VLP size distribution, morphology and surface features.

Gold nanoparticles: the importance of physiological principles to devise strategies for targeted drug delivery - Accepted Manuscript

Madhusudhan R. Papasani, Guankui Wang, Rodney A. Hill — 2012-02-02

Abstract: Nanotechnology and its promise for clinical translation to targeted drug delivery with limited accompanying toxicity provide exciting research opportunities that demand multidisciplinary approaches. To make rapid progress in the design of nano-platforms for drug delivery and towards their use in the clinic, basic, mechanistic studies must first be tested in vitro and then progress to in vivo studies in animal models, incorporating an understanding of body functioning. Recently, gold nanoparticles (AuNPs) have gained much attention as model drug delivery platforms due to their advantageous surface characteristics that allow easy functionalization with chemicals and biological molecules and also to their apparently low toxicity. Here we review recent in vitro and in vivo research progress with AuNPs as drug delivery platforms and suggest experimental strategies for future studies for efficacious, targeted delivery.

Initial studies of mechanical compression on neurogenesis with neonatal neural stem cells - Uncorrected Proof

Leyla Esfandiari, Michelle Paff, William C. Tang — 2012-01-27

Abstract: In this article we demonstrate the effect of mechanical compression on the behavior of cultured neural stem cells using a microelectromechanical system platform. Polydimethylsiloxane (PDMS)-based stretchable substrates were used on a neurosphere (NS) assay to investigate the role of mechanical forces on the formation of radial glial processes and neuronal migration. To induce mechanical compression on NS, the PDMS culturing substrate was patterned with micron-sized wells. NS were cultured on the prestretched device. After 48 hours, when the NS had grown to the size of the well's width, the stretched substrate was released. The experimental results showed that applied mechanical compression on neural stem cells could be a factor accelerating the radial glial formation, which is associated with neurogenesis and neuronal migration.Graphical Abstract: Polydimethylsiloxane (PDMS)-based stretchable platforms were used on neurosphere (NS) assay to investigate the role of mechanical forces on the formation of radial glial processes and neuronal migration. To induce mechanical compression on NS, the PDMS culturing substrate was patterned with micron-sized wells. NS were cultured on the prestretched device. After 48 hours, when the NS had grown to the size of the well’s width, the stretched substrate was released. The experimental results showed that applied mechanical compression on neural stem cells could be a factor accelerating the radial glial formation, which is associated with neurogenesis and neuronal migration.

pH-Dependent nanostructure based on isoquinoline-cyclodextrin conjugate for thrombosis therapy - Uncorrected Proof

2012-01-16

Abstract: The modification of 3S-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (THIQA) with β-cyclodextrin (β-CD) provides an oral antithrombotic agent, 6-(3′S-isoquinoline-3′-carboxylaminoethylamino)-6-deoxy-β-CD (THIQA-β-CD). In aqueous solution THIQA-β-CD undergoes intermolecular inclusion complexation and forms pH-dependent nanostructures. The morphological feature of THIQA-β-CD is a nanocloud consisting of numerous particles that are 5 nm – 6 nm in diameter at pH 3.0. The nanocloud switches to a nanorod ranging from 100 nm to 385 nm in length at pH 7.2, then to nanowires of 50 nm to 530 nm in length at pH 10.1. THIQA-β-CD, which has unusual nanostructures, offers enhanced stability in blood. Inhibition of thrombin-induced platelet aggregation in vitro and demonstrated antithrombotic efficacy in vivo. This investigation demonstrated that the modification of THIQA with β-CD is a promising approach for clinical therapy of thrombus disease. The pH-dependent nanostructures of conjugate provide the desired in vivo antithrombotic activity and in vitro stability in blood.Graphical Abstract: The modification of 3S-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (THIQA) with β-cyclodextrin (β-CD) provides an oral anti-thrombotic agent, THIQA-β-CD. In aqueous solution THIQA-β-CD undergoes self-assembly and forms pH-dependent nanostructures via intermolecular inclusion complexation. THIQA-β-CD with unusual nanostructures offers enhanced stability in blood, inhibition of thrombin induced platelet aggregation in vitro and high in vivo anti-thrombotic efficacy.

Improving interstitial transport of macromolecules through reduction in cell volume fraction in tumor tissues - Uncorrected Proof

Sarah McGuire, Fan Yuan — 2012-01-16

Abstract: Interstitial transport of large molecules and nanoparticles is an important concern in nanomedicine-mediated cancer treatment. To that end, the study was proposed to improve the transport through enlargement of extracellular space by treating tumors with hypertonic solution of mannitol and cytotoxic agents (e.g., ethacrynic acid [ECA]), which could effectively shrink and kill cells, respectively. In the study, the improvement in interstitial penetration of dextran was investigated ex vivo using rat fibrosarcoma tissues sectioned into 600 μm slices. Experimental data showed that the hypertonic solution was more effective than ECA for improving interstitial penetration of dextran with molecular weights ranging from 4000 to 2,000,000. The extent of improvement depended on the size of dextran molecules and the time when the treatment was applied. Results from the study suggested that increases in both size and connectedness of interstitial pathways were important for improvement of interstitial transport of large molecules and nanoparticles.Graphical Abstract: Interstitial transport of macromolecules and nanoparticles in tumors can be improved through enlargement of extracellular space. In this study, the enlargement was achieved by treating tumor tissues with hypertonic solution of mannitol or a cytotoxic agent that could effectively shrink and kill cells. The treatments increased both the uniformity of distributions and the total amount of macromolecules diffused into tumor tissues.

Electrostatic assembly of a DNA superparamagnetic nano-tool for simultaneous intracellular delivery and in situ monitoring - Uncorrected Proof

Frédéric Geinguenaud, Inès Souissi, Remi Fagard, Laurence Motte, Yoann Lalatonne — 2012-01-16

Abstract: A superparamagnetic γFe2O3 nanocarrier was developed, characterized by spectroscopic methods and evaluated for the delivery of a decoy oligonucleotide (dODN) in human colon carcinoma SW 480 cells. This nanoparticle-dODN bioconjugate (γFe2O3@dODN) was designed to target the signal transducer and activator of transcription 3, STAT3, a key regulator of cell survival and proliferation. We exploited a simple precipitation-redispersion mechanism for the direct and one-step complexation of a labeled decoy oligonucleotide with iron oxide nanoparticles (NPs). The cell internalization of the decoy γFe2O3@dODN nanoparticles is demonstrated and suggests the potential for DNA delivery in biological applications. Despite the increasing use of NPs in biology and medicine, convenient methods to quantify them within cells are still lacking. In this work, taking advantage of the nonlinear magnetic behavior of our superparamagnetic NPs, we have developed a new method to quantify in situ their internalization by cells.Graphical Abstract: A superparamagnetic gFe2O3 nanocarrier was developed combining a delivery system of an oligonucleotide and a magnetic nanoprobe for in-situ monitoring. Such dual nanosystem was designed for targeting the signal transducer and activator of transcription 3, STAT3, a key regulator of cell survival and proliferation.

Harnessing nanoparticles to improve toxicity after head and neck radiation - Uncorrected Proof

2012-01-16

Abstract: This article reports the evaluation of cerium oxide (CeO2) nanoparticles' ability to decrease xerostomia and radiation-induced dermatitis in mice after head and neck radiation. Mice were irradiated using an IC160 x-ray system. Two cohorts were included: (A) No-radiation and (B) 30 Gy/6 fractions, and were randomized into three groups: (1) saline, (2) 15 nM CeO2 and (3) 15 μM CeO2. Stimulated salivary flow and radiation-induced dermatitis were evaluated post radiation. Stimulated sialometry demonstrated improved salivary production in all CeO2 groups in comparison with controls (flow: 204 vs. 115 μL/10 minutes, P = 0.0002). One week post radiation, G-III dermatitis decreased in the 15 μM group in comparison with controls (10% versus 100% incidence, respectively). There was decreased skin hyperpigmentation at 12 weeks in the 15-μM group in comparison with 15-nM and non-CeO2 groups (50%, 70%, and 90% G-II, respectively). This study suggests that CeO2 may be radioprotective for salivary production and reduces G-III dermatitis and skin hyperpigmentation incidence. CeO2 as radioprotectant may be a feasible concept during radiotherapy.Graphical Abstract: Radiation effects in the absence and presence of CeO2. Figure A: Sialometry 6 weeks after radiation suggests a dose-dependent decrease in salivary function. Figure B: Effects of CeO2 on salivary protection after radiation exposure. Results demonstrate a difference in saliva production between radiation-only controls and mice receiving radiation plus CeO2. Figure C: Effects of nanoceria on skin hyperpigmentation. Mice treated with 15 nM CeO2 nanoparticles (NPs) demonstrated a lower incidence of Grade II (33.33%) and a higher incidence of Grade I (66.67%) hyperpigmentation. Mice treated with 15 µM CeO2 NPs had an equal incidence of Grade I and II hyperpigmentation.

Preclinical evaluation of a pulmonary delivered paclitaxel-loaded lipid nanocarrier antitumor effect - Corrected Proof

Mafalda Videira, António J. Almeida, Àngels Fabra — 2011-12-29

Abstract: Lung cancer remains a leading cause of death due to the low efficacy of chemotherapy, mainly related to the administration route used. Therefore, alternative administration routes are needed. Paclitaxel (PTX) is an insoluble anticancer drug active against solid tumors, such as those found in lung cancer, that has stimulated an intense research effort over recent years. Solid lipid nanoparticles (SLNs) are potential carriers for poorly soluble drugs, being biodegradable systems that served as alternatives to the usual colloidal carriers. That system was used to deliver PTX to the lungs and seem to fulfill the requirements for an optimum particulate carrier. Furthermore, PTX-loaded SLN pulmonary administration provided a target administration, which is expected to avoid high concentration of the drug at nontarget tissues, reducing toxicity, and increasing the drug's therapeutic index. The rationale of this study was to deliver a colloidal system to the lung lymphatics through a pulmonary route for cancer therapy.Graphical Abstract: Lung cancer remains a leading cause of death due to low efficacy of chemotherapy, which is mainly related to the administration route used. Solid lipid nanoparticles (SLNPs) are potential carriers for poorly soluble drugs, being alternative biodegradable systems to the usual colloidal carriers. This system was used to deliver paclitaxel (PTX) to the lungs and seem to fulfil the requirements for an optimum particulate carrier. Furthermore, PTX-loaded SLNP pulmonary administration provided a target administration, which is expected to avoid high concentration of the drug at nontarget tissues, reducing toxicity and increasing the drug's therapeutic index. The rationale of this study was to deliver a colloidal system to the lung lymphatics through a pulmonary route for cancer therapy.

Activation of TrkB receptors by NGFβ mimetic peptide conjugated polymersome nanoparticles - Corrected Proof

2011-12-28

Abstract: Activation of tyrosine kinase receptor B (TrkB), a neurotrophin receptor, has been shown to increase neuronal cell survival and promote regeneration. Stimulation of the TrkB receptor by neurotrophic growth factors has been identified as a possible therapeutic target for the treatment of neurodegenerative disorders. However, growth factor delivery is problematic because of a short half-life in vivo. We have conjugated hNgf-EE, a short peptide mimetic of NGFβ to the surface of polymersome nanoparticles and shown that they are capable of activating the TrkB receptor in vitro in the SHSY-G7 cell line. We propose that polymersomes could act as a scaffold for the delivery of TrkB activating moieties and that the polymersome size and polyethylene glycol surface have been shown to increase in vivo retention time. These multifunctional nanoparticles have potential for the treatment of neurodegenerative disorders by TrkB activation.Graphical Abstract: TrkB activation by hNgf EE conjugated polymersomes. The graphical abstract shows activation of TrkB receptors by polymesome supported hNgf EE peptides. Phosphorylation of TrkB receptors lead to stimulation of the MAPK/ERK, PLCγ and PI3K signaling pathway which promote cell survival.

Albumin coupled lipid nanoemulsions of diclofenac for targeted delivery to inflammation - Uncorrected Proof

Kandadi Prabhakar, Syed Muzammil Afzal, Goparaboina Surendar, Veerabrahma Kishan — 2011-12-28

Abstract: Diclofenac lipid nanoemulsions (DLNEs) were prepared with different compositions. Based on size, PDI, zeta potential, and in vitro drug release, the optimized DLNEs (DLNE-4 and DLNE-7) were developed and evaluated for drug content, entrapment efficiencies, and stability in comparison to the control formulation (DLNE-1). The albumin was coupled to DLNE-7 globules (DLNE-8) by water soluble carbodiimide (EDC) method, purified, and quantified by modified Bradford method. The pharmacokinetic study was conducted in inflammation (granuloma air pouch model) induced rats. The maximum peak concentration of DLNE-8 was almost fourfold to fivefold in comparison to drug solution in granuloma air pouch fluid (GAPF). The therapeutic availability (TA) of DLNE-8 was 2.89, 2.34, and 1.66 times that of drug solution, DLNE-4 and DLNE-7, respectively. The GAPF/serum ratio of diclofenac from DLNE-8 was above one at all time points indicating the targeting potential of albumin ligated LNEs to inflammatory sites.Graphical Abstract: Diclofenac lipid nanoemulsions (DLNEs) were prepared with different compositions. Optimized formulations were developed based on size, PDI, zeta potential, and in vitro drug release. The optimized DLNEs were evaluated for drug content and entrapment efficiencies and stability. The albumin was coupled to DLNE-7 globules by EDC method and quantified by modified Bradford method. Granuloma air pouch was developed in rats to study in vivo pharmacokinetics. The rate and extent of absorption of diclofenac from albumin coupled LNE (DLNE-8) in granuloma air pouch fluid was higher than that of all other formulations indicating the preferential accumulation of drug at inflammatory site.

Nanostructured silver vanadate as a promising antibacterial additive to water-based paints - Corrected Proof

2011-12-26

Abstract: In this article, we report the use of nanostructured silver vanadate as a promising antibacterial additive to water-based paints that has potential for applications in bathrooms, kitchens, and hospital environments. This hybrid nanomaterial was prepared by a simple and fast precipitation reaction involving silver nitrate and ammonium vanadate, dismissing the hydrothermal treatment. The preparation involved using Ag vanadate nanowires (β-AgVO3) with diameters ranging from 20 to 60 nm and decorated with silver (Ag) nanoparticles (NPs) with diameters ranging from 5 to 40 nm. Results of antibacterial tests show that this hybrid material has a promising antibacterial activity against several types of bacteria strains, such as methicillin-resistant Staphylococcus aureas (MRSA), Enterococcus faecalis, Escherichia coli, and Salmonella enterica Typhimurium. The evaluated material exhibits antibacterial activity 30 times larger than that of Oxacillin. In addition, this nanomaterial was tested as an antibacterial additive to water-based paints, and formulations with 1% show a 4-mm inhibition zone against a MRSA strain.Graphical Abstract: Nanostructured silver vanadate is a promising antibacterial additive to water-based paints that is potential for applications in bathrooms, kitchens and hospitals environments thus certainly contributing to decrease the number of hospital infections

Mono-dispersed high magnetic resonance sensitive magnetite nanocluster probe for detection of nascent tumors by magnetic resonance molecular imaging - Corrected Proof

Chunfu Zhang, Xuan Xie, Sheng Liang, Mingli Li, Yajie Liu, Hongchen Gu — 2011-12-26

Abstract: Sensitive molecular imaging and detection of tumors or their supporting neovascularity require high-avidity, target-specific probes, which produce robust signal amplification compatible with a sensitive high-resolution imaging modality. In this context, we fabricated a high magnetic resonance (MR)-sensitive magnetite nanocluster (MNC) probe specific for tumor angiogenesis by assembly of hydrophobic superparamagnetic iron oxide nanoparticles (SPIONs) with (Mal)mPEG-PLA copolymer into cluster and subsequent encoding c(RGDyC) peptide on the cluster (RGD-MNC) for detection of nascent tumors. We found that RGD-MNC is highly sensitive (r2 = 464.94 s-1mM-1) and specific for αvβ3-positive cells. Both nascent (35 ± 6.6 mm3) and large tumors (256 ± 22.3 mm3) can be registered by RGD-MNC and detected by MR imaging (MRI), with the nascent tumors demonstrating more pronounced MR contrast. Immunohistochemical studies revealed that MR signal decrease was closely correlated with histological characteristics of tumors (microvessel density and αvβ3 expression levels) at different growth stages.Graphical Abstract: Due to its high sensitivity and specificity, both nascent and big tumors can be detected by RGD-MNC, and the MRI contrast is highly correlated with angiogenic vessel densities and αvβ3 integrin expression levels of tumors at different growth stages.

Polystyrene nanoparticles affecting blood coagulation - Corrected Proof

Cecilia Oslakovic, Tommy Cedervall, Sara Linse, Björn Dahlbäck — 2011-12-26

Abstract: The association of nanoparticles (NPs) with blood coagulation proteins may influence the natural balance between pro- and anticoagulant pathways. We investigated whether polystyrene NPs, when added to human plasma, affected the generation of thrombin in plasma. Amine-modified NPs were found to decrease the thrombin formation due to binding of factors VII and IX to the NPs, which resulted in depletion of the respective protein in solution. In contrast, carboxyl-modified NPs were able to act as a surface for activation of the intrinsic pathway of blood coagulation in plasma. These results highlight the influence of NPs on a biologically important pathway.Graphical Abstract: This article explores schematic picture of the different effects on blood coagulation by polystyrene nanoparticles (NPs). Blood coagulation can be activated either through the intrinsic/contact pathway or through the extrinsic pathway. Amine-modified NPs bind FVII and FIX, which leads to a decrease in thrombin formation. Carboxyl-modified NPs are able to activate the intrinsic pathway of coagulation by activation of FXII.

Quantitative characterization of the lipid encapsulation of quantum dots for biomedical applications - Corrected Proof

2011-12-26

Abstract: The water solubilization of nanoparticles is key for many applications in biomedicine. Despite the importance of surface functionalization, progress has been largely empirical and very few systematic studies have been performed. Here we report on the water solubilization of quantum dots using lipid encapsulation. We systematically evaluate the monodispersity, zeta potential, stability, and quantum yield for quantum dots encapsulated with single and double acyl–chain lipids, pegylated double acyl–chain lipids, and single alkyl–chain surfactant molecules with charged head groups. We show that charged surfactants and pegylated lipids are important to obtain monodisperse suspensions with high yield and excellent long-term stability.Graphical Abstract: Lipid encapsulation is a biomimetic approach to water solubilization of nanoparticles that takes advantage of hydrophobic interactions to drive formation of an outer leaflet. The physicochemical properties of lipid-encapsulated nanoparticles, such as monodispersity, zeta potential, stability, and quantum yield, can be optimized by varying the composition of the lipid layer through combinations of single- and double–acyl chain lipids, pegylated double–acyl chain lipids, and single–alkyl chain surfactant molecules with charged head groups.

ERα signaling imparts chemotherapeutic selectivity to selenium nanoparticles in breast cancer - Corrected Proof

Kiritkumar K. Vekariya, Jasmine Kaur, Kulbhushan Tikoo — 2011-12-26

Abstract: The present study focuses on the synthesis of stable selenium nanoparticles (SeNPs) and the elucidation of their mechanism of action in preventing the growth of mammary tumors. Selenious acid and reduced glutathione in the presence of sodium alginate were used as precursors for synthesis of SeNPs. Cell viability and expression of apoptotic markers (pp38, Bax, and cytochrome c) were assessed in MCF-7 and MDA-MB-231 breast cancer cells treated with SeNPs. Reduction in tumor volume was measured in rats with dimethylbenz[a]anthracene-induced mammary tumors. Synthesized SeNPs ranged in size from 40 to 90 nm and were stable up to 3 months of storage. We report that SeNP-induced cell death and expression of pp38, Bax, and cytochrome c were significantly higher in estrogen receptor-α (ERα)–positive cells (MCF-7) but not in ERα-negative cells (MDA-MB-231). Interestingly, animals showing significant decrease in tumor volume (small tumors) had lower levels of ERα as compared with animals showing a nonsignificant decrease in tumor volume (large tumor). This is the first report in our knowledge suggesting that the anticancer activity of SeNPs correlates with the level of ERα in breast cancer cells both in vivo and in vitro.Graphical Abstract: MCF-7 cells, which are rich in ERα receptors are more susceptible to apoptosis when treated with SeNPs as compared with SeNPs–treated MDA-MB-231 cells, which do not have many ERα receptors. Thus, we propose a causal relationship between the levels of ERα and SeNPs–mediated cell death.

Nanoscale surface modification favors benign biofilm formation and impedes adherence by pathogens - Corrected Proof

2011-12-26

Abstract: We have found in vitro that a biofilm of benign Escherichia coli 83972 interferes with urinary catheter colonization by pathogens, and in human studies E. coli 83972–coated urinary catheters are associated with lower rates of catheter-associated urinary tract infections. We hypothesized that modifying surfaces to present mannose ligands for the type 1 fimbriae of E. coli would promote formation of dense E. coli 83972 biofilms, thereby interfering with surface colonization by Enterococcus faecalis, a common uropathogen. We covalently immobilized mannose on silicon substrates by attaching amino-terminated mannose derivative to carboxylic acid–terminated monolayers via amidation. Fluorescence microscopy showed that E. coli 83972 adherence to mannose-modified surfaces increased 4.4-fold compared to unmodified silicon surfaces. Pre-exposing mannose-modified surfaces to E. coli 83972 established a protective biofilm that reduced E. faecalis adherence by 83-fold. Mannose-fimbrial interactions were essential for the improved E. coli 83927 adherence and interference effects.Graphical Abstract: We covalently immobilized a mannose derivative on silicon substrates by attaching an oligo(ethylene glycol) mannoside with an amino-terminal group onto carboxylic acid–terminated monolayers via amidation. The resulting monolayers presented mannose ligands for the receptors on the type 1 fimbriae of Escherichia coli 83972. E. coli 83972 is a benign organism, and an established biofilm of this organism can prevent surface attachment by pathogens, such as Enterococcus faecalis. Our results showed that surface modification with mannose-presenting monolayers promoted biofilm formation by the benign organism and resulted in exclusion of the pathogen from the surface, a process known as bacterial interference.

Characterization of high-affinity peptides and their feasibility for use in nanotherapeutics targeting leukemia stem cells - Corrected Proof

2011-12-26

Abstract: Peptides featuring the LR(S/T) motif were identified that could specifically bind to the C-type lectin-like molecule-1 (CLL1), a protein preferentially expressed on acute myeloid leukemia stem cells (LSCs). Micellar nanoparticles were covalently decorated with CLL1-targeting peptides for targeted drug delivery. The resulting peptide-coated nanoparticles were 13.5 nm in diameter and could be loaded with 5 mg of daunorubicin per 20 mg of telodendrimers. These “targeting nanomicelles” transported the drug load to the interior of cells expressing CLL1 and to LSCs isolated from clinical specimens in vitro, but did not bind to normal blood or normal hematopoietic stem cells. The presence of CLL1-targeting peptides on the surface of the nanomicelles enabled the improved binding and delivery of substantially more daunorubicin into the cells expressing CLL1 and CD34+ leukemic cells compared with unmodified nanomicelles. In conclusion, nanomicelles coated with CLL1-targeting peptides are potentially useful for eradicating LSCs and improving leukemia therapy.Graphical Abstract: A chemotherapeutic drug, drug combinations and/or radioisotopes are loaded inside nanomicelles. Targeting ligands against leukemia stem cell (LSC) surface molecules are decorated on the surface of nanomicelles. After intravenous administration, these targeting nanomicelles can specifically deliver high-concentration therapeutic agents to and eradicate LSC. In addition, the therapeutic agents can diffuse into blood circulation to kill leukemic cells throughout the body. Furthermore, formulation of chemotherapeutic drugs in nanomicelles can decrease therapy-related toxicity and improve treatment outcomes.

Improving intraperitoneal chemotherapeutic effect and preventing postsurgical adhesions simultaneously with biodegradable micelles - Corrected Proof

2011-12-07

Abstract: The two major concerns after cytoreductive surgery of abdominal and pelvic malignancies are residual tumors and peritoneal adhesions, which are inevitable and have great impact on prognosis. Therefore, to improve the intraperitoneal chemotherapeutic effect and prevent postsurgical adhesions simultaneously after surgery, we developed a novel strategy that combines the controlled drug delivery system (CDDS) with an antiadhesion barrier. Biodegradable poly(ethylene glycol)–poly(ɛ-caprolactone)–poly(ethylene glycol) (PECE) copolymer formed micelles in water, which turned instantly into a nonflowing gel at body temperature as a result of micellar aggregation. Effectiveness of doxorubicin-loaded PECE micelles (Dox-M) in improving intraperitoneal chemotherapeutic effect and preventing adhesions was investigated. Subsequently, we established a novel mouse model for postsurgical residual tumors and peritoneal adhesions, in which Dox-M could improve intraperitoneal chemotherapeutic effect and prevent postsurgical peritoneal adhesions simultaneously. Thus, it is a promising strategy to combine the CDDS and barrier method to improve the intraperitoneal chemotherapeutic effect and prevent peritoneal adhesions simultaneously after surgery.Graphical Abstract: A novel strategy to improve the effect of postsurgical intraperitoneal chemotherapy and prevent peritoneal adhesions simultaneously after cytoreductive surgery is proposed in this work, which combines a controlled drug delivery system with a barrier method. Our results indicated that the drug-loaded micelles showed an impressive antitumor and adhesion prevention effect in a novel mouse model of postsurgical residual tumors and peritoneal adhesion.

Release profile and transscleral permeation of triamcinolone acetonide loaded nanostructured lipid carriers (TA-NLC): in vitro and ex vivo studies - Corrected Proof

2011-11-23

Abstract: Nanostructured lipid carriers (NLC) have been developed for sustained release of triamcinolone acetonide (TA), a corticosteroid commonly indicated for macular edema, neovascularization, and other ocular inflammatory disorders. TA-NLC were prepared by high-pressure homogenization and characterized for in vitro release by dialysis bag. Ex vivo permeation profile was assessed using rabbit sclera isolated and mounted in Franz diffusion cells. TA-NLC were placed in episcleral donor compartment and choroidal side was perfused with HEPES buffer. Tissue sections underwent drug wash-out, following analysis by validated RP-HPLC of drug content and perfused fractions collected over 24 hours. Drug release followed one-order kinetics and permeability studies confirmed that TA is able to diffuse across rabbit sclera in sustained profile, following zero-order kinetics. Strong tissue binding was observed, providing a drug depot. These findings are of potential use when designing future TA therapy strategies for ocular diseases of posterior segment.Graphical Abstract: Nanostructured Lipid Carriers (NLC) have been developed for sustained release of Triamcinolone Acetonide (TA), a corticosteroid commonly indicated for macular oedema, neovascularization and other ocular inflammatory conditions. Drug release from NLC followed one-order kinetics. Ex vivo permeability studies confirmed that TA is able to diffuse through rabbit sclera in a sustained profile, following a zero-order kinetic model. Strong tissue binding was observed, providing a drug depot.

An investigation on the antibacterial, cytotoxic, and antibiofilm efficacy of starch-stabilized silver nanoparticles - Corrected Proof

2011-11-23

Abstract: The increased emergence of drug resistant microbes creates a major challenge to the scientific community for successful development of effective therapeutics. The antimicrobial activities of silver ions are well known, but limited information is available on the effects of green silver-nanoparticles (AgNPs) on human pathogens. In this article, we evaluated the antibacterial activity of starch-stabilized AgNPs against a panel of human pathogens commonly associated with air, water and food borne infections. The shape and size distribution of AgNPs were characterized by transmission electron microscopy. We showed that AgNPs were more effective against Gram-positive and Gram-negative pathogens as compared with acid-fast bacteria. AgNPs were not cytotoxic to macrophages at the bactericidal concentration and can augment intracellular killing potential of macrophages. Furthermore, we showed that AgNPs disrupt biofilm formation and exhibit better antibacterial activity compared to human cationic antimicrobial peptide LL-37. In summary, our data suggest AgNPs as a promising template for the design of novel antibacterial agents.Graphical abstract: Graphical representation of different activities of AgNPs against bacteria and macrophages. Starch-stabilized AgNPs exhibit antimicrobial activity, inhibit biofilm formation, no cytotoxic effect on mouse macrophages, and kill intracellular bacteria.

In vitro mechanistic study of cell death and in vivo performance evaluation of RGD grafted PEGylated docetaxel liposomes in breast cancer - Corrected Proof

Sachin Naik, Deepa Patel, Krishna Chuttani, Anil K. Mishra, Ambikanandan Misra — 2011-11-23

Abstract: Objectives of the investigations were to prepare RGD grafted docetaxel liposomes (RGD-PEG-LP-DC) using supercritical fluid technology and evaluate it in vitro for cytotoxicity, DNA content analysis, mechanism of cell death, and in vivo for pharmacokinetic and biodistribution studies in BALB/c mice. The RGD-PEG-LP-DCs were found to be most cytotoxic in BT-20 and MDA-MB-231 cell lines. The flowcytometry results shows at 48 hours, 96% G2 phase arrest for RGD-PEG-LP-DC at 5 nM drug concentration. The mode of cell death was found to be mainly by necrosis at low drug equivalent concentration (1 nM) and by apoptosis at high drug equivalent concentration (10 nM). With increase in time and concentration the mode of cell death by apoptosis was found to be increasing. Biodistribution demonstrated that site specific drug distribution, t1/2, and MRT improved significantly for RGD-PEG-LP-DC. From the studies site specific and sustained intracellular drug delivery from RGD-PEG-LP-DCs may provide promising strategy in enhancing embattled against breast cancer treatment.Graphical Abstract:

Nanoresonator chip-based RNA sensor strategy for detection of circulating tumor cells: response using PCA3 as a prostate cancer marker - Corrected Proof

2011-11-23

Abstract: There is widespread interest in circulating tumor cells (CTCs) in blood. Direct detection of CTCs (often < 1/mL) is complicated by a number of factors, but the presence of ∼103 to 104 copies of target RNA per CTC, coupled with simple enrichments, can greatly increase detection capability. In this study we used resonance frequency shifts induced by mass-amplifying gold nanoparticles to detect a hybridization sandwich bound to functionalized nanowires. We selected PCA3 RNA as a marker for prostate cancer, optimized antisense binding sites, and defined conditions allowing single nucleotide mismatch discrimination, and used a hybrid resonator integration scheme, which combines elements of top-down fabrication with strengths of bottom-up fabrication, with a view to enable multiplexed sensing. Bound mass calculated from frequency shifts matched mass estimated by counting gold nanoparticles. This represents the first demonstration of use of such nanoresonators, which show promise of both excellent specificity and quantitative sensitivity.Graphical Abstract: Sandwich hybridization assay for DD3 RNA. A primary ASO (green) is covalently attached to the NW surface. Incubation with DD3 RNA (blue) results in hybridization. Subsequent hybridization with the ASO:AuNP (red) completes the sandwich. Formation of the sandwich hybridization complex adds mass to the anchored NW nanoresonator, which results in a shift in the resonance frequency of the NW, which is quantitatively proportional to the number of complexes bound. The resonance frequency shift is measured using laser interferometry.

In vitro study of magnetite-amyloid β complex formation - Corrected Proof

2011-11-23

Abstract: Biogenic magnetite (Fe3O4) has been identified in human brain tissue. However, abnormal concentration of magnetite nanoparticles in the brain has been observed in different neurodegenerative pathologies. In the case of Alzheimer's disease (AD), these magnetic nanoparticles have been identified attached to the characteristic brain plaques, which are mainly formed by fibrils of amyloid β peptide (Aβ). However, few clues about the formation of the magnetite-Aβ complex have been reported. We have investigated the interaction between these important players in AD with superconducting quantum interference, scanning electron microscope, surface plasmon resonance, and magnetic force microscopy. The results support the notion that the magnetite-Aβ complex is created before the synthesis of the magnetic nanoparticles, bringing a highly stable interaction of this couple.Graphical Abstract: Abnormal concentration of magnetite nanoparticles in the brain has been observed in different neurodegenerative pathologies. In the case of Alzheimer's disease (AD), these magnetic nanoparticles have been identified attached to the fibrils of amyloid β peptide (Aβ). However, few clues about the formation of the magnetite-Aβ complex have been reported. This work represents a first approach to study the association of magnetite nanoparticles and Aβ in vitro.Iron can adopt both the ferric (Fe3+) and ferrous (Fe2+) valence states in vivo. The ability to change from one state to the other confers a very important role on iron in different biological oxidation and transport processes. However, the disruption of the normal iron metabolism can entail harmful consequences because Fe3+ and, especially, Fe2+ generate toxic free radicals mainly via the Fenton reaction.

Multifunctional nanoplatforms for fluorescence imaging and photodynamic therapy developed by post-loading photosensitizer and fluorophore to polyacrylamide nanoparticles - Corrected Proof

2011-11-23

Abstract: We report a novel post-loading approach for constructing a multifunctional biodegradable polyacrylamide (PAA) nanoplatform for tumor-imaging (fluorescence) and photodynamic therapy (PDT). This approach provides an opportunity to post-load the imaging and therapeutic agents at desired concentrations. Among the PAA nanoparticles, a formulation containing the photosensitizer, HPPH [3-(1′-hexyloxyethyl)pyropheophorbide-a], and the cyanine dye in a ratio of 2:1 minimized the undesirable quenching of the HPPH electronic excitation energy because of energy migration within the nanoparticles and/or Förster (fluorescence) resonance energy transfer (FRET) between HPPH and cyanine dye. An excellent tumor-imaging (NIR fluorescence) and phototherapeutic efficacy of the nanoconstruct formulation is demonstrated. Under similar treatment parameters the HPPH in 1% Tween 80/5% aqueous dextrose formulation was less effective than the nanoconstruct containing HPPH and cyanine dye in a ratio of 2 to 1. This is the first example showing the use of the post-loading approach in developing a nanoconstructs for tumor-imaging and therapy.Graphical Abstract: Long wavelength photosensitizer (PS) and NIR cyanine dye (CD) were post-loaded to PAA NPs in variable ratios. Among all the preparations, the nanoplatform containing the PS and CD in a ratio of two to one (2:1) showed the best tumor-imaging (fluorescence) and PDT efficacy (six of ten mice [BALB/c mice bearing Colon 26 tumors] were tumor free on day 60). Under similar treatment parameters the PS (HPPH) in 1% Tween 80/5% aqueous dextrose formulation was 20% less effective.

Paclitaxel-loaded polymeric micelles based on poly(ɛ-caprolactone)-poly(ethylene glycol)-poly(ɛ-caprolactone) triblock copolymers: in vitro and in vivo evaluation - Corrected Proof

Linhua Zhang, Yingna He, Guilei Ma, Cunxian Song, Hongfan Sun — 2011-11-18

Abstract: The purpose of this study was to develop polymeric nanoscale drug-delivery system (nano-DDS) for paclitaxel (PTX) from poly(ɛ-caprolactone)-poly(ethylene glycol)-poly(ɛ-caprolactone) (PCL-PEG-PCL, PCEC) copolymers, intended to be intravenously administered, able to improve the therapeutic efficacy of the drug and devoid of the adverse effects of Cremophor EL. Both of the PTX-loaded polymeric micelles and polymersomes were successfully prepared from PCEC copolymers. The obtained PTX-loaded micelles exhibited core-shell morphology with satisfactory size (93 nm), and were favorable for intravenous injection. In vitro cytotoxicity demonstrated that the cytotoxic effect of PTX-loaded micelles was lower than that of Taxol (Bristol-Myers Squibb, Princeton, New Jersey). Pharmacokinetic results indicated that the PTX-loaded micelles had longer systemic circulation time and slower plasma elimination rate than those of Taxol. Furthermore, PTX-loaded micelles showed greater tumor growth-inhibition effect in vivo on EMT6 breast tumor, in comparison with Taxol. Therefore, the prepared polymeric micelles might be potential nano-DDS for PTX delivery in cancer chemotherapy.Graphical Abstract: Flower-like PTX-loaded polymeric micelles from PCL4000-PEG8000-PCL4000 were successfully prepared by thin film method. The obtained micelles exhibited apparent core-shell morphology with satisfactory size (93 nm), which were favorable for intravenous injection. In vivo anti-tumor study showed that the PTX-loaded polymeric micelles could significantly inhibit EMT6 breast tumor growth and reduce the toxicity of PTX. The prepared PTX-loaded polymeric micelles have the potential to be developed as an effective anticancer nano-scale drug delivery system for cancer chemotherapy.

Self-Assembly and liver targeting of sulfated chitosan nanoparticles functionalized with glycyrrhetinic acid - Corrected Proof

Qin Tian, Xiu-Hua Wang, Wei Wang, Chuang-Nian Zhang, Ping Wang, Zhi Yuan — 2011-11-17

Abstract: A drug carrier based on glycyrrhetinic acid-modified sulfated chitosan (GA-SCTS) was synthesized. The glycyrrhetinic acid (GA) acted as both a hydrophobic group and a liver-targeting ligand. The GA-SCTS micelles displayed rapid and significant ability to target the liver in vivo. The IC50 for doxorubicin (DOX)-loaded GA-SCTS micelles (DOX/SA-SCTS micelles) against HepG2 cells was 54.7 ng/mL, which was extremely lower than the amount of no-GA-modified DOX-loaded micelles. In addition, DOX/SA-SCTS micelles could target specifically the liver cancer cells. They had higher affinity for the liver cancer cells (HepG2 cells) than for the normal liver cells (Chang liver cells). There was nearly 2.18-fold improvement in uptake of the DOX/SA-SCTS micelles by HepG2 cells than that by Chang liver cells. These results indicate that GA-SCTS is not only an excellent carrier for drugs, but also a potential vehicle for liver-cancer targeting.Graphical Abstract: Glycyrrhetinic acid (GA)-modified carriers are more efficient for liver- or hepatocyte-targeted delivery; however, less information is available about their biodistribution, and there is no information that GA-modified drug delivery system has the ability to target specifically the liver cancer cells. Therefore, GA-modified sulfated chitosan (GA-SCTS) polymeric micelles were designed and prepared in this work. The biodistribution and in vitro cellular uptake assays were investigated. GA-SCTS micelles had several advantages, such as the low CAC (critical aggregation concentration) value, high encapsulation efficacy, and high loading content for doxorubicin (DOX). In addition, they displayed rapid and significant ability to target the liver in vivo. It is important to note that GA-SCTS micelles had higher affinity for HepG2 cells (liver cancer cells) than for Chang liver cells (liver normal cells).

Photothermal release of small molecules from gold nanoparticles in live cells - Corrected Proof

2011-11-17

Abstract: The ability of gold (Au) nanoparticles (NPs) to generate heat efficiently by absorbing visible and near-infrared (NIR) light holds great promise as a means to trigger chemical and biochemical events near the NPs. Previous demonstrations show that pulsed laser irradiation can selectively elicit the release of a fluorescent dye covalently anchored to the NP surface through a heat-labile linker without measurably changing the temperature of the surroundings. This article reports that the authors demonstrate the biological efficacy of this approach to photodelivery by showing that the decorated AuNPs are rapidly internalized by cells, are stable under physiological conditions, are nontoxic, and exhibit nonlethal photorelease following exposure to pulsed laser radiation. These observations, further supported by the versatility of our delivery motif, reaffirm the potential for further development of nonlethal photothermal therapeutics and their future relevance to such fields as gene therapy and stem-cell differentiation.Graphical Abstract: Spherical 15-nm gold nanoparticles (AuNPs) were decorated with a modified fluorescent dye anchored to the particle surface by a mercaptoalkyl chain and an intervening, heat-labile oxabicycloheptene linker. Solutions containing the decorated NPs were injected into live oocytes and introduced to Chinese hamster ovary cells via their growth media. Both cell cultures were shown to be viable following exposure to the NP solutions and subsequent pulsed laser irradiation, which resulted in visible increases in fluorescence attributable to diffusion of the dye away from the NP surface following cleavage of the oxabicycloheptene structure elicited by photothermal heating of the AuNPs.

Development and evaluation of a dual-modality (MRI/SPECT) molecular imaging bioprobe - Corrected Proof

Ripen Misri, Dominik Meier, Andrew C. Yung, Piotr Kozlowski, Urs O. Häfeli — 2011-11-17

Abstract: Specific bioprobes for single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) have enormous potential for use in cancer imaging in near-future clinical settings. The authors describe the development of dual modality molecular imaging bioprobes, in the form of magnetic nanoparticles (NPs) conjugated to antibodies, for SPECT and MRI of mesothelin-expressing cancers. The bioprobes were developed by conjugating 111In labeled antimesothelin antibody mAbMB to superparamagnetic iron oxide NPs. Our experimental findings provide evidence that such bioprobes retain their magnetic properties as well as the ability to specifically localize in mesothelin-expressing tumors. It is anticipated that combining SPECT with MR will help obtain both functional and anatomical imaging information with high signal sensitivity and contrast, thereby providing a powerful diagnostic tool for early diagnosis and treatment planning of mesothelin-expressing cancers.Graphical Abstract: A molecular imaging agent comprising magnetic nanoparticles bioconjugated to radioactive antibodies was developed for dual-modality imaging of tumors with SPECT and MRI. This dual-modality imaging approach is advantageous due to the ability of each imaging modality to image different properties or processes, allowing more precise localization of the tumors.

Lapatinib/Paclitaxel polyelectrolyte nanocapsules for overcoming multidrug resistance in ovarian cancer - Corrected Proof

2011-11-17

Abstract: The sonication-assisted layer-by-layer (SLBL) technology was developed to combine necessary factors for an efficient drug-delivery system: (i) control of nanocolloid size within 100 – 300 nm, (ii) high drug content (70% wt), (iii) shell biocompatibility and biodegradability, (iv) sustained controlled release, and (v) multidrug-loaded system. Stable nanocolloids of Paclitaxel (PTX) and lapatinib were prepared by the SLBL method. In a multidrug-resistant (MDR) ovarian cancer cell line, OVCAR-3, lapatinib/PTX nanocolloids mediated an enhanced cell growth inhibition in comparison with the PTX-only treatment. A series of in vitro cell assays were used to test the efficacy of these formulations. The small size and functional versatility of these nanoparticles, combined with their ability to incorporate various drugs, indicates that lapatinib/PTX nanocolloids may have in vivo therapeutic applications.Graphical Abstract: I) A principal scheme of LbL nanoparticles formation from insolubile drugs. II) The citotoxic potential of Lapatinib / Paclitaxel polyelectrolyte nanocapsules was evaluated in a chemoresistant ovarian cancer cell line. After administration, drugs-loaded nanoparticles exerted a significant increase in the therapeutic activity compared with free paclitaxel.

Bioactive silica-based nanoparticles stimulate bone-forming osteoblasts, suppress bone-resorbing osteoclasts, and enhance bone mineral density in vivo - Corrected Proof

2011-11-17

Abstract: Bone is a dynamic tissue that undergoes renewal throughout life in a process whereby osteoclasts resorb worn bone and osteoblasts synthesize new bone. Imbalances in bone turnover lead to bone loss and development of osteoporosis and ultimately fracture, a debilitating condition with high morbidity and mortality. Silica is a ubiquitous biocontaminant that is considered to have high biocompatibility. The authors report that silica nanoparticles (NPs) mediate potent inhibitory effects on osteoclasts and stimulatory effects on osteoblasts in vitro. The mechanism of bioactivity is a consequence of an intrinsic capacity to antagonize activation of NF-κB, a signal transduction pathway required for osteoclastic bone resorption but inhibitory to osteoblastic bone formation. We further demonstrate that silica NPs promote a significant enhancement of bone mineral density (BMD) in mice in vivo, providing a proof of principle for the potential application of silica NPs as a pharmacological agent to enhance BMD and protect against bone fracture.Graphical Abstract: Activation of the NF-κB signal transduction pathway is central to the formation and activity of bone-degrading osteoclasts but is potently inhibitory to the differentiation and activity of bone building osteoblasts. Silica nanoparticles suppress osteoclasts and stimulate osteoblasts in vitro by antagonizing activation of NF-κB. When injected into mice in vivo, silica nanoparticles promote the accretion of bone mineral density. Consequently silica nanoparticles may have clinical potential as novel anti-osteoporotic pharmaceuticals.

Double-walled carbon nanotubes trigger IL-1β release in human monocytes through Nlrp3 inflammasome activation - Corrected Proof

2011-11-17

Abstract: Because of their outstanding physical properties, carbon nanotubes (CNTs) are promising new materials in the field of nanotechnology. It is therefore imperative to assess their adverse effects on human health. Monocytes/macrophages that recognize and eliminate the inert particles constitute the main target of CNTs. In this article, we report our finding that double-walled CNTs (DWCNTs) synergize with Toll-like receptor agonists to enhance IL-1β release in human monocytes. We show that DWCNTs–induced IL-1β secretion is exclusively linked to caspase-1 and to Nlrp3 inflammasome activation in human monocytes. We also establish that this activation requires DWCNTs phagocytosis and potassium efflux, but not reactive oxygen specied (ROS) generation. Moreover, inhibition of lysosomal acidification or cathepsin-B activation reduces DWCNT-induced IL-1β secretion, suggesting that Nlrp3 inflammasome activation occurs via lysosomal destabilization. Thus, DWCNTs present a health hazard due to their capacity to activate Nlrp3 inflammasome, recalling the inflammation caused by asbestos and hence demonstrating that they should be used with caution.Graphical Abstract: Scheme explaining the mechanism leading to the activation of the Nlrp3 inflammasome by DWCNTs. IL-1β secretion in response to DWCNT treatment requires a first signal dependent on TLRs. This TLR-dependent signal leads to pro-IL1β synthesis. Then, the DWCNTs are phagocytosed by monocytes, causing phagosomal acidification and cathepsin B activation and finally leading to Nlrp3 inflammasome activation. This activation also requires a potassium efflux, but not ROS generation.

Novel micelles based on amphiphilic branched PEG as carriers for fenretinide - Corrected Proof

2011-11-16

Abstract: This study reports on the preparation and evaluation of amphiphilic macromolecules based on branched polyethylene glycol covalently linked with alkyl hydrocarbon chains. These macromolecules easily dissolved in an aqueous environment, with formation of micellar nanoaggregates endowed with hydrophobic inner cores capable of hosting fenretinide by complexation. The complexes increased fenretinide aqueous solubility, while hindering its release as a free drug in an aqueous environment. Particle size analysis indicated dimensional suitability of the complexes for intravenous administration. Neuroblastoma cell lines (SH-SY5Y and NGP) exhibited increased sensitivity to fenretinide in complex as compared to free drug, associated with higher intracellular concentrations of fenretinide observed after treatment with the complex. Transmission electronic microscopy images revealed endocytosis of the micellar complex. Moreover, fenretinide conversion to its metabolite 4-oxo-fenretinide was delayed in cells treated with the complex, further supporting the hypothesis that fenretinide may be absorbed by micellar transport and exposed to the cytoplasm for conversion to its metabolite only after micelle destabilization.Graphical Abstract: Branched PEG linked to an alkyl chain self-assembles in water with formation of micelles that entrap fenretinide into their hydrophobic inner cores. (A) Scheme; (B) TEM image.

Cancer cell response to nanoparticles: criticality and optimality - Corrected Proof

Hirak Kumar Patra, Anjan Kr Dasgupta — 2011-11-16

Abstract: A stochastic variation in size and electrical parameters is common in nanoparticles. Synthesizing gold nanoparticles with a varying range of size and zeta potential, we show that there is clustering at certain regions of hydrodynamic diameter and zeta potentials that can be classified using k-clustering technique. A cluster boundary was observed around 50 nm, a size known for its optimal response to cells. However, neither size nor zeta potential alone determined the optimal cellular response (e.g., percentage cell survival) induced by such nanoparticles. A complex interplay prevails between size, zeta potential, nature of surface functionalization, and extent of adhesion of the cell to a solid matrix. However, it follows that the ratio of zeta potential to surface area, which scales as the electrical field (by Gaussian law), serves as an appropriate indicator for optimal cellular response. The phase plot spanned by fractional survival and effective electric field (charge density) indicates a positive correlation between mean cell survival and the magnitude of the electric field. The phase plot spanned by fractional survival and effective electric field (charge density) associated with the nanosurface shows a bifurcation behavior. Wide variation of cell survival response is observed at certain critical values of the surface charge density, whereas in other ranges the cellular response is well behaved and more predictable. Existence of phase points near the critical region corresponds to wide fluctuation of nanoparticle-induced response, for small changes in the nanosurface property. Smaller nanoparticles with low zeta potential (e.g., those conjugated with arginine) can have such an attribute (i.e., higher electrical field strength), and eventually they cause more cell death. The study may help in optimal design of nanodrugs.Graphical Abstract: A stochastic variation found in wet-route synthesis of nanoparticles, clustering occurs at certain regions of effective electric field (charge density) associated with the nanosurface, showing a series of distinct clusters that grow in size with increase in the field strength. Particles with lower zeta potential and smaller nanoparticles correspond to the smallest cluster, and this condition seems suitable for optimal cytotoxicity behavior. In the presence of a smaller field one finds larger clusters, implying a bi-stable survival behavior with small fluctuations in nanosurface resulting in large fluctuations in cell survival response.

New strategy of efficient inhibition of cancer cells by carborane carboxylic acid–CdTe nanocomposites - Corrected Proof

2011-11-16

Abstract: Nanoconjugates composed of drug molecules encapsulated in quantum dots (QDs) attract enormous attention due to their promising bioimaging and biomedical applications. Here, the anticancer efficiency of potential pharmacophore agents (o-carborane (Cb), o-carborane-C-carboxylic acid (Cbac1), and o-carborane-C(1)C(2)-dicarboxylic acid (Cbac2) coupling with cadmium telluride QDs capped with cysteamine (CA-CdTe QDs)) have been explored. Compared with free CA-CdTe QDs, the composites consisting of Cbac1/Cbac2 and safe-dosage QDs can greatly improve the inhibition efficiency toward SMMC-7721 hepatocellular carcinoma cells with the aid of our real-time cell bioelectronic sensing system and the MTT assay. The enhanced cytotoxicity correlates with increased intracellular reactive oxygen species generation and cell apoptosis. Confocal laser scanning fluorescent microscopy shows improved cellular uptake and drug distribution of the Cbac1/Cbac2-CdTe QDs nanoconjugates. This work raises the possibility that the carborane pharmacophore in combination with QDs or other anticancer drugs may be viable for efficient cancer diagnosis and chemotherapy.Graphical Abstract: In this contribution, the specific interactions of carborane pharmacophore agents, namely carborane–carboxylic acid derivatives (denoted as Cbac1 and Cbac2), with cadmium telluride quantum dots capped with cysteamine (CA-CdTe QDs) are explored. The corresponding carborane–carboxylic acid derivatives–CdTe nanoconjugates exhibit synergistic inhibition on target cancer cells, raising the possibility of carborane anticancer agents in combination with safe-dosage QDs for cancer chemotherapy.

Gold-peptide nanoconjugate cellular uptake is modulated by serum proteins - Corrected Proof

2011-11-02

Abstract: Gold nanoparticles (AuNPs, 20 nm) were conjugated with two different cysteine-terminated peptides. Radio-ligand binding studies were conducted to characterize AuNP-peptide binding, suggesting both covalent and noncovalent interactions. The interactions of serum proteins with AuNP-peptide nanoconjugates were determined using gel electrophoresis and dynamic light scattering. Serum proteins rapidly bound the nanoconjugates (15 minutes). The cellular uptake of free peptides and nanoconjugates into mouse myogenic (Sol8) cells was investigated in the absence or presence of serum. In the absence of serum, peptides presented as nanoconjugates showed significantly higher intracellular fluorescence signals compared to those in the presence of serum (P < 0.05), suggesting that serum proteins inhibit AuNP-mediated peptide delivery. The cellular uptake of nanoconjugates was also confirmed using transmission electron microscopy. These data suggest that AuNP-peptide nanoconjugates are a useful platform for intracellular delivery of therapeutics. However, a deeper understanding of the mechanisms regulating their uptake and intracellular trafficking is needed.Graphical Abstract: Fetal bovine serum (FBS) affects cellular uptake of nanoconjugates. The figure shows confocal fluorescence images of Sol8 cells incubated with AuNP-peptide A nanoconjugates (2 hours) in the presence (A) or the absence (B) of FBS. Fluorescence images suggest that in the absence of FBS, AuNP-mediated uptake of peptide A is enhanced. FBS proteins overcoat nanoconjugates, and this may lead to alterations to retrograde trafficking pathways.

Preclinical study of the cyclodextrin-polymer conjugate of camptothecin CRLX101 for the treatment of gastric cancer - Corrected Proof

2011-10-26

Abstract: Camptothecin showed remarkable anticancer activity in animal models of cancer but was restricted in clinical use for its adverse toxicity in patients. The preclinical efficacy of CRLX101, a nanoparticle (NP) assembly containing cyclodextrin-based polymer and camptothecin was evaluated by in vitro cytotoxicity in gastric cancer cell lines and in vivo antitumor effects in human gastric cancer cell line BGC823 xenografts. Treated tumor sections were analyzed for presence of NPs and compared with vehicle control tumors for hypoxia and angiogenesis. Gastric cancer cell lines showed high in vitro cytotoxicity for CRLX101 and also showed strong antitumor activity in vivo. Electron micrographs revealed the intracellular presence of NPs in close proximity to vesicles. A significant decrease in expressions of carbonic anhydrase, VEGF, and CD31 proteins in treated tumors indicated an inhibition of hypoxia and angiogenesis. The results provide preclinical data for gastric adenocarcinoma.Graphical Abstract: Most of the chemotherapeutic drugs used in the clinic today are limited by their toxic side effects. For the past several decades, numerous methods have been employed to improve the therapeutic efficacy of anticancer drugs by designing molecularly targeted agents that modulate the pathways associated with tumor progression. Additionally, targeted drug delivery has been advancing to alter the therapeutic index by making more drug molecules available to the diseased site and reducing systemic drug exposure.

Visible light–responsive core-shell structured In2O3@CaIn2O4 photocatalyst with superior bactericidal properties and biocompatibility - Corrected Proof

2011-10-26

Abstract: Antibacterial activity of photocatalytic substrates is primarily induced by ultraviolet light irradiation. Visible light–responsive photocatalysts were recently discovered, offering greater opportunity to use photocatalysts as disinfectants in our living environment. The development of antibacterial photocatalysts, however, has mainly focused on titanium oxide (TiO2)–related materials with antibacterial properties not comparable with conventional chemical disinfectants. This study demonstrated that a core-shell structured In2O3@CaIn2O4 substrate has superior visible light–induced bactericidal properties, as compared with several commercially available and laboratory-prepared visible light–responsive photocatalysts. The high performance is enhanced by more easily photoexcited electron transfer between the interfaces of In2O3 and CaIn2O4 to minimize the electron-hole recombination during photocatalysis. Additionally, when compared with TiO2-based photocatalysts, In2O3@CaIn2O4 treatments did not induce significant cell death and tissue damage, implying a superior biocompatibility. These findings suggest that In2O3@CaIn2O4 may have potential application in the development of a safer and highly bactericidal photocatalyst.Graphical Abstract: The In2O3@CaIn2O4 nanoparticle is a visible light–responsive photocatalyst that has superior bactericidal activity as compared with several commercially available and laboratory-prepared photocatalysts. The high performance is enhanced by more easily photoexcited electron transfer between the interfaces of In2O3 and CaIn2O4 to minimize the electron-hole recombination during photocatalysis. Additionally, In2O3@CaIn2O4 exhibits a superior biocompatibility when compared with TiO2-based visible light–responsive photocatalysts and can be used in vivo. These findings suggest that In2O3@CaIn2O4 may have potential application in the development of a safer and highly bactericidal photocatalyst.

Classification of lung cancer histology by gold nanoparticle sensors - Corrected Proof

Orna Barash, Nir Peled, Ulrike Tisch, Paul A. Bunn, Fred R. Hirsch, Hossam Haick — 2011-10-26

Abstract: We propose a nanomedical device for the classification of lung cancer (LC) histology. The device profiles volatile organic compounds (VOCs) in the headspace of (subtypes of) LC cells, using gold nanoparticle (GNP) sensors that are suitable for detecting LC-specific patterns of VOC profiles, as determined by gas chromatography–mass spectrometry analysis. Analyzing the GNP sensing signals by support vector machine allowed significant discrimination between (i) LC and healthy cells; (ii) small cell LC and non–small cell LC; and between (iii) two subtypes of non–small cell LC: adenocarcinoma and squamous cell carcinoma. The discriminative power of the GNP sensors was then linked with the chemical nature and composition of the headspace VOCs of each LC state. These proof-of-concept findings could totally revolutionize LC screening and diagnosis, and might eventually allow early and differential diagnosis of LC subtypes with detectable or unreachable lung nodules.Graphical Abstract: Experimental procedure for in vitro studies of lung cell line head space. The samples were analyzed by both the gold nanoparticle sensors (B, C, F) and gas chromatography–mass spectrometry (D, E, G).

Cytotoxicity of functionalized carbon nanotubes in J774A macrophages - Corrected Proof

2011-10-26

Abstract: Cytotoxicity of carbon nanotubes (CNTs) is a prime concern for its use as antigen carriers. Here we evaluated the cytotoxic effect of unpurified (UP-CNTs), purified (P-CNTs), fluorescein isothiocyanate–functionalized (FITC-CNTs), and Entamoeba histolytica 220-kDa lectin–functionalized CNTs (L220-CNTs) in J774A macrophage (MOs) cell line. Cell viability and apoptosis were analyzed by MTT and TUNEL assays, respectively. Cyclooxygenase-2 (COX-2) was analyzed by reverse transcription–polymerase chain reaction. Cytotoxicity at 6.0 mg/L was higher with UP-CNTs > P-CNTs > FITC-CNTs, showing a decrease in cell viability and an increase in apoptosis. In contrast, MOs interacted with L220-CNTs showed an increase in cell viability without signs of apoptosis. Although UP-CNTs and P-CNTs exhibited COX-2 induction with 6.0 mg/L, functionalized CNTs were able to induce COX-2 at concentrations as low as 0.06 mg/L. These results suggest that functionalization decreases toxicity, and that L220-CNTs may be an excellent candidate for the production of a nanovaccine against amebiasis.Graphical Abstract: Viability of macrophages interacted with carbon nanotubes (CNTs) at different concentrations at 24 hours. Each bar represents mean ± SD of two experiments done in triplicates (n = 6). a, P < 0.01 denotes significant differences between mean values measured in the indicated group as compared to control without stimulus (CTL). b, P < 0.01 denotes differences between mean values for CNTs at different concentrations. c, P < 0.01 denotes differences between mean values for a particular concentration among different CNTs. CNT-FITC, fluorescein isothiocyanate–functionalized CNTs; CNT-L220, Entamoeba histolytica-220 kDa lectin–functionalized CNTs; P, purified; UP, unpurified.

Synergistic effects of cell-penetrating peptide Tat and fusogenic peptide HA2-enhanced cellular internalization and gene transduction of organosilica nanoparticles - Corrected Proof

2011-10-26

Abstract: The nonviral gene delivery system is an attractive alternative to cancer therapy. A new kind of gelatin-silica nanoparticles (GSNPs) was developed through a two-step sol–gel procedure. To improve the transfection efficacy, GSNPs modified with different fusion peptides (Tat, HA2, R8, Tat/HA2, and Tat/R8) were prepared for particle size, zeta potential, cellular uptake, hemolysis activity at physiological pH (7.0) or acidic pH (5.0), and condensation of plasmid DNA. The results suggest that the sizes and zeta potentials of GS-peptide conjugates were 147 – 161 nm and 19 – 33 mV, respectively; GS-peptide conjugates exhibited low cytotoxicity; the plasmid DNA was readily entrapped at a GS-peptide/pDNA weight ratio of 50 – 200. The in vitro and in vivo studies demonstrated that the synergistic effects of cell-penetrating peptide Tat and fusogenic peptide HA2 could promote the efficient cellular internalization, endosome escape, and nucleus targeting, hence delivering the therapeutic nucleic acid efficiently.Graphical Abstract: The synergistic effects of cell-penetrating peptide Tat and fusogenic peptide HA2 could promote the efficient cellular internalization, endosome escape, and nuclear targeting of the therapeutics' nucleic acid, hence delivering genes efficiently.

Enhancement of focused ultrasound with microbubbles on the treatments of anticancer nanodrug in mouse tumors - Corrected Proof

Chung-Yin Lin, Jia-Rong Li, Hsiao-Ching Tseng, Ming-Fang Wu, Win-Li Lin — 2011-10-26

Abstract: Ultrasound sonication with microbubbles (MBs) has the potential to enhance the delivery of nanoparticles into the sonicated tumors. In this study, we investigated the feasibility of focused ultrasound (FUS) sonication with MBs to improve nanodrug delivery and tumor treatment. Tumor-bearing mice were first injected with MBs (SonoVue) intravenously, were then sonicated at the tumors with FUS sonication, and were finally injected with the PEGylated liposomal doxorubicin (DOX). The accumulation of DOX in tumors with time, the tumor growth responses for initial treated tumor size and DOX dosage, and the response for an additional sonication after DOX injection were studied. The results demonstrate that FUS sonication with MBs can significantly enhance DOX accumulation in the sonicated tumor at 24 hours after treatment. A significant hindrance to tumor growth is achieved for a small tumor with a low dose, whereas large tumors require a higher dose.Graphical Abstract: Schematic diagram showing the arrangement of focused ultrasound beam for mouse tumor treatment. A 5-mm-thick ultrasound transmission gel was mantled over the mouse skin, and the focused ultrasound beam was targeted on the tumor. The ultrasound beam was circularly scanned with a diameter of 3 mm during sonication.

In vitro study of ethosome penetration in human skin and hypertrophic scar tissue - Corrected Proof

Zhen Zhang, Yan Wo, Yixin Zhang, Danru Wang, Rong He, Huijin Chen, Daxiang Cui — 2011-10-26

Abstract: The purpose of this study is to characterize a novel transdermal delivery carrier, ethosomes containing 5-fluorouracil. The delivery of drugs from ethosomes in human hypertrophic scar (HS) and the mechanisms of action of ethosomes in human HS were investigated. Percutaneous ethosome permeation was evaluated in vitro in human HS and skin using a Franz's cell. The amount of 5-fluorouracil that permeated HS and skin after 24 hours was most abundant in ethosomes via HS (E-Scar), followed by hydroethanolic solution via HS (H-Scar), ethosomes via skin (E-Skin), and hydroethanolic solution via skin (H-Skin). The penetration of ethosomes in HS and skin was analyzed by ethosomes fluorescently labeled with rhodamine 6GO using confocal laser scanning microscopy. The fluorescence intensity after application for 24 hours was highest in E-Scar, followed by E-Skin, H-Scar, and H-Skin, which indicates the penetration of ethosomes in HS was greatest. In conclusion, we consider that ethosomes are a highly efficient carrier in HS.Graphical Abstract: The penetration of ethosomes encapsulating 5-FU was investigated by CLSM in hypertrophic scar (HS) tissue and normal skin. Highly efficient penetration was observed in HS, and 74-nm ethosomes could be a potential drug carrier in the treatment of HS.

Quantitative and qualitative flow cytometric analysis of nanosized cell-derived membrane vesicles - Corrected Proof

2011-10-24

Abstract: Nanosized cell-derived membrane vesicles are increasingly recognized as therapeutic vehicles and high-potential biomarkers for several diseases. Currently available methods allow bulk analysis of vesicles but are not suited for accurate quantification and fail to reveal phenotypic heterogeneity in membrane vesicle populations. For such analyses, single vesicle-based, multiparameter, high-throughput methods are needed. We developed a fluorescence-based, high-resolution flow cytometric method for quantitative and qualitative analysis of nanosized membrane vesicles. Proof of principle was obtained by single-particle analysis of virions and liposomes. Further validation was obtained by quantification of cell-derived nanosized membrane vesicles from cell cultures and body fluids. An important aspect was that the technology was extended to detect specific proteins on individual vesicles. This allowed identification of exosome subsets and phenotyping of individual exosomes produced by dendritic cells (DCs) undergoing different modes of activation. The described technology allows quantitative, multiparameter, and high-throughput analysis of a wide variety of nanosized particles and has broad applications.Graphical Abstract: Flow cytometric analysis of heterogeneous populations of cell-derived nanosized membrane vesicles.

Development of a method for magnetic labeling of platelets - Corrected Proof

2011-10-24

Abstract: Platelets play a dominant role in the pathogenesis of bleeding disorders and cardiovascular pathology (e.g., myocardial infarction). Nonradioactive labeling of platelets may offer several clinical applications, ranging from survival studies of transfused platelet concentrates to studies on the pathogenesis of stroke. We used ferucarbotran superparamagnetic nanoparticles (NPs) for cell labeling. Platelets incorporated these NPs by endocytosis (without linkers or binding agents). Flow cytometry using FITC-conjugated magnetic NPs showed ex vivo labeling of about 98% of platelets; NPs were predominantly located inside the platelet granules as confirmed by fluorescence microscopy and transmission electron microscopy. Iron concentrations of 2 pg per platelet were reached as determined by atomic absorption spectroscopy. This will enable sensitive ex vivo determination of transfused labeled platelets, allowing survival studies. In vitro, labeled platelets gave a clear signal by 7 Tesla magnetic resonance tomography. Magnetic labeling of platelets may offer a new tool for diagnosis and research in transfusion medicine and cardiovascular medicine.Graphical abstract: Human platelets were labeled with superparamagnetic iron oxide nanoparticles. Platelets incorporate these nanoparticles by endocytosis without the need of specific linkers or binding agents as confirmed by electron and fluorescence microscopy and cellular iron determination. Optimal conditions for the visualization of labeled platelets by MRI were determined. Magnetically labeled platelets may offer a new tool for diagnosis and research in cardiovascular disorders.

Induction of tumor-specific immunity by multi-epitope rat HER2/neu-derived peptides encapsulated in LPD Nanoparticles - Corrected Proof

Seyed Amir Jalali, Mojtaba Sankian, Jalil Tavakkol-Afshari, Mahmoud Reza Jaafari — 2011-10-24

Abstract: The goal of study was first to design multi-epitope peptides from the rat HER2/neu (rHER2/neu) oncogene and then to evaluate the effectiveness of these peptides encapsulated in liposome-polycation-DNA(LPD) nanoparticles (NPs) for the induction of immune response in BALB/c mice. Four multi-epitope peptides derived from the rHER2/neu were designed and different groups of mice were vaccinated with free peptides or peptides encapsulated in NPs. Two of the four tested peptides (p5 and p435), as well as their combinations with the LPD NPs induced a significantly higher IFN-γ and CTLresponses in comparison with the control groups. Consequently, these responses led to lower tumor sizes and longer survival time in TUBO tumor mice model. Our results demonstrate that rHER2/neu-peptides (p5 and p435) and their encapsulation can induce an antigen-specific immunity. This study also presents the first attempt to evaluate the effectiveness of natural rHER2/neu-peptides containing CTL multi-epitope and encapsulated in LPD NPs.Graphical Abstract: Liposome-polycation-DNA (LPD) nanoparticles efficiently encapsulate the multi-epitope rat HER2/neu peptides and CpG-ODN adjuvant, deliver them to the antigen presenting cells for MHC class-I presentation, induce cytotoxic T lymphocyte response in BALB/c mice and results to lower tumor sizes and longer survival time in TUBO tumor mice model which overexpress HER2/neu oncogene.