Synthesis and gelation characteristics of photo-crosslinkable star Poly(ethylene oxide-co-lactide-glycolide acrylate) macromonomers

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• 作者：Seyedsina Moeinzadeh^a ; Saied Nouri Khorasani^a ; Junyu Ma^a ; Xuezhong He^a ; Esmaiel Jabbari ; ^a ; ^{jabbari@engr.sc.edu"" rel=""nofollow}
• 关键词：Star macromonomer ; Degradable ; Gelation kinetics
• 刊名：Polymer
• 出版年：2011
• 出版时间：18 August 2011
• 年：2011
• 卷：52
• 期：18
• 页码：3887-3896
• 全文大小：830 K

文摘

Viability of encapsulated cells in situ crosslinkable macromonomers depends strongly on the minimum concentration of polymerization initiators and monomers required for gelation. Novel 4-arm poly(ethylene oxide-co-lactide-glycolide acrylate) (SPELGA) macromonomers were synthesized and characterized with respect to gelation, sol fraction, degradation, and swelling in aqueous solution. SPELGA macromonomers were crosslinked in the absence of N-vinyl-2-pyrrolidone (NVP) monomer to produce a hydrogel network with a shear modulus of 27 ± 4 kPa. The shear modulus of the gels increased by 170-fold as the macromonomer concentration was increased from 10 to 25 wt % . Sol fraction ranged between 8 and 18 % . Addition of only 0.4 mol % NVP to the polymerization mixture increased modulus by 2.2-fold from 27 ± 4 (no NVP) to 60 ± 10 kPa. The higher modulus was attributed to the dilution effect of polymer chains in the sol, by delaying the onset of diffusion-controlled reaction, and cross-propagation of the growing chains with network-bound SPELGA acrylates. Degradation of SPELGA gels depended on water content and density of hydrolytically degradable ester groups.