Original Article
Spatial controlled multistage nanocarriers through hybridization of dendrimers and gelatin nanoparticles for deep penetration and therapy into tumor tissue

https://doi.org/10.1016/j.nano.2017.01.008Get rights and content

Abstract

Most nanoparticles (NPs) have difficulty deeply penetrating into tumor tissues. Here, we designed a spatially controlled multistage nanocarrier by encapsulating small polyamidoamine (PAMAM) dendrimers (~5 nm) within large gelatin NPs (~200 nm). This multistage nanocarrier is meant to be stable during systemic circulation and to leak through tumor vasculature walls by the enhanced permeation and retention (EPR) effect. Afterwards, this multistage nanocarrier release PAMAM dendrimers in response to the high matrix metalloproteinase-2 (MMP-2) enzymes in the tumor microenvironment, and further transport into tumor cells. In this study, the demonstrated high intracellular uptake and deep penetration into tumor model verified the effective enzymes-responsively and spatially controlled multistage penetration of these combined nanocarriers. In addition, these multistage nanocarrier were further loaded with anti-tumor drug methotrexate (MTX) and evaluated both in vitro and in vivo to investigate their anti-tumor effect, which demonstrated that this multistage nanocarrier hold great potential in improving anti-tumor efficiency.

Graphical Abstract

A spatially controlled multistage nanocarrier with small polyamidoamine (PAMAM) dendrimers (~5 nm) encapsulating into large gelatin NPs (~200 nm). With an outer gelatin layer to act as a shield, these multistage nanocarriers were more stable during systematic circulation for their relatively large particle size and electrically neutral surface, than positively charged PAMAM dendrimers alone. However, gelatin NPs were degraded via matrix metalloproteinase-2 (MMP-2) enzymes in tumor tissue, triggering an internal release of PAMAM dendrimers that possessed small particle sizes and a positive charge, which guaranteed improved subsequent deep penetration and high intracellular uptake into tumor cells through electrostatic adsorptive endocytosis.

Image 1
  1. Download : Download high-res image (364KB)
  2. Download : Download full-size image

Section snippets

Preparation of multistage nanocarriers

Blank gelatin nanoparticles were prepared by the nanoprecipitation method as reported earlier with some modifications.38 Briefly, 40 mg of gelatin was dissolved in 2 mL deionized water at 50 °C. This solution was added dropwise to 30 mL of methanol-containing Lutrol F127 (2%), and subsequently crosslinked with 0.5 mL of a glutaraldehyde solution (5%). The system was stirred overnight to allow particles to form crosslinks. After crosslink, the suspension was centrifuged by centrifuge (TG16-WS,

Preparation of FITC labeled PAMAM dendrimers

The H1-NMR results are shown in Figure 1, A. From the H1-NMR spectrum of FITC-PAMAM, both the characteristic peaks of PAMAM dendrimers (δ = 2.484 ppm, δ = 2.627 ppm, δ = 2.751–2.849 ppm, and δ = 3.110–3.489 ppm) and of FITC (δ = 6.548–6.641 ppm, δ =7.208 ppm, and δ = 7.939 ppm) were found. The UV spectrum also proved that the FITC and PAMAM has been conjugated successfully as the absorbance peak of FITC has moved from 492 nm to 501 nm, which is similar to our previous research. The integral value of these

Discussions

In this study, we designed a tumor-microenvironment-responsive multistage nanocarrier that remains stable at a relatively large scale during blood circulation. After entering tumor tissues, the large-scale nanocarriers were digested by MMP-2 enzymes and subsequently released smaller-scale dendrimers. Released dendrimers were able to deeply penetrate into tumor tissues and enter tumor cells with high efficiency; therefore, these nanocarriers may have applications as ideal drug carriers to

Acknowledgements

This work was supported by the National Natural Science Foundation of China [grant numbers 81402859].

References (41)

  • K. Qian et al.

    The studies about doxorubicin-loaded p(N-isopropyl-acrylamide-co-butyl methylacrylate) temperature-sensitive nanogel dispersions on the application in TACE therapies for rabbit VX2 liver tumor

    J Control Release

    (2015)
  • S. Sunoqrot et al.

    Prolonged blood circulation and enhanced tumor accumulation of folate-targeted dendrimer-polymer hybrid nanoparticles

    J Control Release

    (2014)
  • R.S. Dhanikula et al.

    Influence of molecular architecture of polyether-co-polyester dendrimers on the encapsulation and release of methotrexate

    Biomaterials

    (2007)
  • M. Bhagat et al.

    Nanocarriers to solid tumors: considerations on tumor penetration and exposure of tumor cells to therapeutic agents

    Curr Pharm Biotechnol

    (2012)
  • B. Chaurasiya et al.

    Influence of tumor microenvironment on the distribution and elimination of Nano-formulations

    Curr Drug Metab

    (2016)
  • H.S. Choi et al.

    Renal clearance of quantum dots

    Nat Biotechnol

    (2007)
  • F. Yuan et al.

    Vascular permeability in a human tumor xenograft: molecular size dependence and cutoff size

    Cancer Res

    (1995)
  • H. Cabral et al.

    Accumulation of sub-100 nm polymeric micelles in poorly permeable tumours depends on size

    Nat Nanotechnol

    (2011)
  • L. Tang et al.

    Investigating the optimal size of anticancer nanomedicine

    Proc Natl Acad Sci U S A

    (2014)
  • J. Wang et al.

    The role of micelle size in tumor accumulation, penetration, and treatment

    ACS Nano

    (2015)
  • Cited by (0)

    View full text