title: Biodegradable amphiphilic block copolymers bearing protected hydroxyl groups: synthesis and characterization.
abstract: A new biodegradable amphiphilic block copolymer, poly(ethylene glycol)-b-poly(L-lactide-co-9-phenyl-2,4,8,10-tetraoxaspiro[5,5]undecan-3-one) [PEG-b-P(LA-co-PTO)], was successfully prepared by ring-opening polymerization (ROP) of L-lactide (LA) and functionalized carbonate monomer 9-phenyl-2,4,8,10-tetraozaspiro[5,5]undecan-3-one (PTO) in the presence of monohydroxyl poly(ethylene glycol) as macroinitiator using Sn(Oct)2 as catalyst. NMR, FT-IR, and GPC studies confirmed the copolymer structure. It could self-assemble into micelles in aqueous solution with critical micelle concentration (CMC) in the magnitude of mg/L, which changed with the composition of the copolymer. After catalytic hydrogenation, copolymers with active hydroxyl groups were obtained. Adhesion and proliferation of Vero cells on the copolymer films showed that the synthesized copolymers were good biocompatible materials. In vitro degradation of the copolymer before and after deprotection was investigated in the presence of proteinase K. The free hydroxyl groups on the copolymers were capable of further modification with biotin. This new amphiphilic block copolymer has great potential for both drug encapsulation and conjugate because of its low CMC and the presence of active hydroxyl groups.
authors.affiliation: State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PR China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Hu
authors.forename: Shi
authors.initials: S
authors.lastname: Liu
authors.forename: Xuesi
authors.initials: X
authors.lastname: Chen
authors.forename: Guojun
authors.initials: G
authors.lastname: Mo
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Xie
authors.forename: Xiabin
authors.initials: X
authors.lastname: Jing
mesh_terms: D000818:Animals; D001711:Biotransformation; D002522:Chlorocebus aethiops; D006878:Hydroxides / Q000737:chemistry / Q000493:pharmacokinetics*; D007773:Lactates / Q000737:chemistry / Q000493:pharmacokinetics*; D011092:Polyethylene Glycols / Q000737:chemistry / Q000493:pharmacokinetics*; D011108:Polymers / Q000737:chemistry / Q000493:pharmacokinetics; D013501:Surface-Active Agents / Q000737:chemistry / Q000493:pharmacokinetics*; D014709:Vero Cells
chemical_list: D006878:Hydroxides; D007773:Lactates; D011108:Polymers; D013501:Surface-Active Agents; C088513:poly(lactic acid-ethylene glycol); D011092:Polyethylene Glycols; C031356:hydroxide ion