文献类型：期刊文献

英文题名：Biodegradable comb-dendritic tri-block copolymers consisting of poly(ethylene glycol) and poly(L-lactide): Synthesis, characterizations, and regulation of surface morphology and cell responses

作者：Gong, Feirong[2];Cheng, Xiaoyan[2];Wang, Shanfeng[1];Wang, Yang[3];Gao, Yun[2];Cheng, Shujun[2]

机构：[1]Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA;[2]E China Univ Sci & Technol, Key Lab Ultrafine Mat, Minist Educ, Sch Mat Sci & Engn, Shanghai 200237, Peoples R China;[3]Fudan Univ, Shanghai Med Coll, Shanghai 200032, Peoples R China

年份：2009

卷号：50

期号：13

起止页码：2775

外文期刊名：POLYMER

收录：;EI(收录号：20092312109290);WOS:【SCI-EXPANDED(收录号:WOS:000267415600005)】；

基金：This work was supported by the 863 Project (2007AA02Z450) from the Ministry of Science and Technology of China. We thank Shanghai Aosi Biological Technology Service Co., Ltd. for the gift of cells and technical assistance for cell Culture.

语种：英文

外文关键词：Polylactide; Comb-dendritic tri-block copolymer; Cell responses

摘要：A series of well-defined dumbbell-shaped tri-block copolymers consisting of comb-like poly(L-lactide) (PLLA) and linear poly(ethylene glycol) (PEG) with narrow molecular weight distributions and varied PLLA arm lengths have been synthesized via the sequential preparation of terminal dendronized poly-hydric PEG and ring-opening polymerization (ROP) of L-lactide (LA). The terminal dendronized poly-hydric PEG was prepared by the conjugation of amine-terminated fourth-generation polyester dendrons with NHS-activated PEG followed by the deprotection of acetonide groups. The length of PLLA arms can be readily controlled by the feed molar ratio of LA monomer to the hydroxyl groups in PEG macro-initiator. Differential scanning calorimetric (DSC) measurements and thermal gravimetric analysis (TGA) have been performed to indicate that the glass transition temperature (T-g), melting point (T-m), degree of crystallinity (chi(c)), and onset decomposition temperature (T-d) of the copolymers are lower than those of the linear polylactide (LPLLA). Self-organized porous structures have been found in the copolymer films after solution casting and solvent evaporation. Honeycomb-like surface morphology could be achieved by adjusting the length of PLLA arms. Meanwhile, surface chemistry of the copolymer films such as surface hydrophobicity and the capability of adsorbing protein increase with the length of PLLA arms. Controllable material properties have been correlated with the in vitro cell responses. No cytotoxicity, of the dumbbell-shaped copolymers has been found using rabbit bone marrow stromal cells (BMSCs). Human embryonic kidney (HEK) 293T cells have been used to reveal the effect of surface characteristics on cell attachment and proliferation. It has been found that cell proliferation has been enhanced significantly on the surfaces of the copolymers with longer PLLA arm lengths because of more favorable surface physicochemical properties. (C) 2009 Elsevier Ltd. All rights reserved.