In vivo cancer imaging by poly(ethylene glycol)-b-poly(ɛ-caprolactone) micelles containing a near-infrared probe

Cho, Hyunah; Indig, Guilherme L.; Weichert, Jamey; Shin, Ho-Chul; Kwon, Glen S.

doi:10.1016/j.nano.2011.06.009

« Previous Next »Nanomedicine: Nanotechnology, Biology and Medicine
Volume 8, Issue 2 , Pages 228-236, February 2012

In vivo cancer imaging by poly(ethylene glycol)-b-poly(ɛ-caprolactone) micelles containing a near-infrared probe

Hyunah Cho, MS
- Department of Pharmaceutical Science, School of Pharmacy, University of Wisconsin, Madison, Wisconsin, USA
Guilherme L. Indig, PhD
- Department of Chemistry and Biochemistry, University of Wisconsin, Milwaukee, Wisconsin, USA
Jamey Weichert, PhD
- Department of Radiology, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, USA
Ho-Chul Shin, MS
- Department of Pharmaceutical Science, School of Pharmacy, University of Wisconsin, Madison, Wisconsin, USA
Glen S. Kwon, PhD
- Department of Pharmaceutical Science, School of Pharmacy, University of Wisconsin, Madison, Wisconsin, USA
- College of Pharmacy, Kyung Hee University, Seoul, South Korea
- Corresponding author: Department of Pharmaceutical Science, School of PharmacyUniversity of Wisconsin, Madison, WI 53705, USA.

Received 10 November 2010; accepted 8 June 2011. published online 27 June 2011.

Abstract

Noninvasive near-infrared (NIR) fluorescence imaging is a promising technique for the intraoperative assessment of solid tumor removal. We incorporated a lipophilic NIR probe, 1,1′-dioctadecyltetramethyl indotricarbocyanine iodide (DiR), in poly(ethylene glycol)-b-poly(ɛ-caprolactone) (PEG-b-PCL) micelles, resulting in DiR solubilization in water, occupying nanoscopic PEG-b-PCL micelles. DiR in a self-quenched or nonquenched state showed different kinetics of release from PEG-b-PCL micelles in vitro; however, both obtained high tumor delineation (tumor-to-muscle ratio of 30–43 from collected organs). These results suggest that PEG-b-PCL micelles with DiR are a promising nanosized imaging agent that will provide a basis for enhanced surgical guidance via NIR visualization of tumors.

From the Clinical Editor

In this paper, noninvasive near-infrared fluorescence imaging coupled with specific lipophilic probes is discussed as a promising technique for intraoperative assessment of solid tumor removal, leading to optimized outcomes for in toto removal of tumors.

Graphical Abstract

PEG-b-PCL micelles migrated into solid tumors with incorporated DiR in either a non-quenched state (left) or a self-quenched state (right) by the EPR effect, delineating solid tumors. Non-quenched DiR displayed a rapid onset of strong fluorescence intensity at solid tumors. On the other hand, self-quenched DiR displayed relatively lower fluorescence intensity, but a gradual increase over time at solid tumors.