Amphiphilic photocleavable block copolymers based on monomethyl poly(ethylene glycol) and poly(4-substituted-ε-caprolactone): synthesis, characterization, and cellular uptake

• Published in: RSC advances Vol. 3; no. 40; pp. 18453 - 18463
• Main Authors: Peng, Kang-Yu, Wang, Shiu-Wei, Hua, Mu-Yi, Lee, Ren-Shen
• Format: Journal Article
• Language: English
• Published: 01.01.2013
• Subjects: Biocompatibility; biodegradability; Block copolymers; Cellular; composite polymers; cytoplasm; doxorubicin; dyes; encapsulation; fluorescence; hydrophilicity; hydrophobicity; indomethacin; irradiation; lactones; Light irradiation; Micelles; nanoparticles; polyethylene glycol; Synthesis; Toxicity; Uptakes
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/c3ra42763c

This paper presents the synthesis of a novel amphiphilic block copolymer containing photodegradable linkers as junction points between hydrophilic and hydrophobic chains. MPEG-ONB-PXCL block copolymers were synthesized by a combination of ROP and "clicks" from a difunctional photoresponsive initiator (ONB). The copolymers are biodegradable and biocompatible, and can self-assemble into photoresponsive micelles. When polymer solutions were exposed to UV, we observed significant changes in the structure and morphology of particles. Fluorescence emission measurements showed that Nile red (NR), a hydrophobic dye, encapsulated by the MPEG-ONB-PXCL micelles, is released upon irradiation because of disruption of the micelles. Light-triggered bursts were observed for Indomethacin (IMC)-loaded MPEG-ONB-PXCL micelles upon at 30 min of light irradiation. No significant toxicity of these nanoparticles was found, at concentrations up to 1000 mu g mL super(-1), before or after light irradiation. The doxorubicin (DOX)-loaded micelles facilitated improved uptake of DOX by HeLa cells within 60 min, and were retained primarily in the cytoplasm.