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Photosensitive Cross‐linked Block Copolymers with Controllable Release
Author(s) -
Yu LiLi,
Lv Cong,
Wu LiZhu,
Tung ChenHo,
Lv WanLiang,
Li ZhongJin,
Tang XinJing
Publication year - 2011
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/j.1751-1097.2011.00894.x
Subject(s) - micelle , copolymer , atom transfer radical polymerization , polymer , polymer chemistry , gel permeation chromatography , monomer , methacrylate , dynamic light scattering , chemistry , ethylene glycol dimethacrylate , polymerization , methyl methacrylate , ethylene glycol , linker , photochemistry , materials science , organic chemistry , nanoparticle , methacrylic acid , nanotechnology , aqueous solution , computer science , operating system
We intend to form photosensitive block copolymer micelles for controllable release of encapsulated substances. Here, we designed and synthesized a new photocleavable cross‐linker (2‐nitrophenyl ethylene glycol dimethacrylate) for methyl methacrylate (MMA) atom transfer radical polymerization. Four different ratios (0:1, 1:26, 1:16, 1:8.8) of the photocleavable cross‐linker to MMA monomer were used and four block copolymers (P0, P1, P2, P3) were synthesized with PEO‐Br as the macroinitiator. Gel permeation chromatography and 1 H NMR studies showed that linear polymer molecules could be cross‐linked by the photocleavable linker. The fluorescence studies of the encapsulated Nile Red (NR) showed that there were lower critical micelle concentrations for the polymer P1, P2 and P3 than polymer P0. And dynamic light scattering and SEM confirmed the formation of polymer micelles. Photolysis experiments demonstrated that NR encapsulated in the polymer micelles could be released upon UV irradiation (365 nm, 11 mW cm −2 ) due to the breakage of the photocleavable linker and the generation of more hydrophilic acid moieties, which destabilized polymer micelles. Our study shows a new strategy for the possibility of photocontrollable drug release for hydrophobic drugs.