Polymeric Micelles Encapsulating Photosensitizer: structure/photodynamic Therapy Efficiency Relation

Biomacromolecules. 2014 Apr 14;15(4):1443-55. doi: 10.1021/bm5000407. Epub 2014 Mar 3.

Abstract

Various polymeric micelles were formed from amphiphilic block copolymers, namely, poly(ethyleneoxide-b-ε-caprolactone), poly(ethyleneoxide-b-d,l-lactide), and poly(ethyleneoxide-b-styrene). The micelles were characterized by static and dynamic light scattering, electron microscopy, and asymmetrical flow field-flow fractionation. They all displayed a similar size close to 20 nm. The influence of the chemical structure of the block copolymers on the stability upon dilution of the polymeric micelles was investigated to assess their relevance as carriers for nanomedicine. In the same manner, the stability upon aging was assessed by FRET experiments under various experimental conditions (alone or in the presence of blood proteins). In all cases, a good stability over 48 h for all systems was encountered, with PDLLA copolymer-based systems being the first to release their load slowly. The cytotoxicity and photocytotoxicity of the carriers were examined with or without their load. Lastly, the photodynamic activity was assessed in the presence of pheophorbide a as photosensitizer on 2D and 3D tumor cell culture models, which revealed activity differences between the 2D and 3D systems.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Culture Techniques / methods
  • Chlorophyll / analogs & derivatives
  • Chlorophyll / chemistry
  • Chlorophyll / pharmacology
  • Drug Carriers / chemistry*
  • Drug Carriers / toxicity
  • Drug Stability
  • Fluorescence Resonance Energy Transfer
  • HCT116 Cells / drug effects
  • Humans
  • Lactones / chemistry
  • Light
  • Micelles
  • Photochemotherapy / methods*
  • Photosensitizing Agents / chemistry*
  • Photosensitizing Agents / pharmacology
  • Polyesters / chemistry
  • Polyethylene Glycols / chemistry
  • Polymers / chemistry*
  • Scattering, Radiation
  • Structure-Activity Relationship

Substances

  • Drug Carriers
  • Lactones
  • Micelles
  • Photosensitizing Agents
  • Polyesters
  • Polymers
  • poly(epsilon-caprolactone-co-ethylene oxide)
  • poly(ethylene glycol)-block-poly(epsilon-caprolactone)
  • Chlorophyll
  • Polyethylene Glycols
  • pheophorbide a