Thermoresponsive and Photocrosslinkable PEGMEMA-PPGMA-EGDMA Copolymers from a One-Step ATRP Synthesis
Thermoresponsive and Photocrosslinkable PEGMEMA-PPGMA-EGDMA Copolymers from a One-Step ATRP Synthesis
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DOI：
10.1021/bm801308q
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发表时间：
2009-04-01
影响因子：
6.2
通讯作者：
Howdle, Steven M.
中科院分区：
文献类型：
--
作者：
Tai, Hongyun;Wang, Wenxin;Howdle, Steven M.
热敏感型和光交联型聚合物可作为组织工程中的可注射支架，在原位形成具有更高力学性能和稳定性的凝胶。它们易于处理，并在光聚合之前保持其形状，用于临床实践。本文报道了以聚乙二醇甲基醚甲基丙烯酸酯(PEGMEMA，M(0)=475)和聚丙二醇甲基丙烯酸酯(PPGMA，M(N)=375)为单官能团单体，以高达30%的乙二醇二甲基丙烯酸酯(EGDMA)为多官能团单体的一步失活增强原子转移自由基聚合(ATRP)，合成了一种具有温度响应性和光交联性的新型共聚物。用凝胶渗透色谱(GPC)和核磁共振氢谱(1)对所合成的PEGMEMA-PPGMA-EGDMA三元共聚物进行了表征，证明了它们具有多乙烯基官能团和超支化结构。这些水溶性共聚物在32℃下表现出较低的临界溶液温度(LCST)行为，与聚(N-异丙基丙烯酰胺)(PNIPAM)相当。该共聚物还可以通过其多乙烯基官能团通过光聚合进行交联化。流变学研究清楚地表明，在高于LcST的温度下形成的光交联凝胶比在低于LcST的温度下形成的光交联凝胶具有更高的存储模数。此外，通过调整共聚物的组成和浓度，可以调整凝胶的交联度，以调整其多孔结构和机械性能。已经生产了存储模数从10到400kpa的广泛范围的水凝胶。
Thermoresponsive and photocrosslinkable polymers can be used as injectable scaffolds in tissue engineering to yield gels in situ with enhanced mechanical properties and stability. They allow easy handling and hold their shapes prior to photopolymerization for clinical practice. Here we report a novel copolymer with both thermoresponsive and photocrosslinkable properties via a facile one-step deactivation enhanced atom transfer radical polymerization (ATRP) using poly(ethylene glycol) methyl ether methylacrylate (PEGMEMA, M(0) = 475) and poly(propylene glycol) methacrylate (PPGMA, M(n) = 375) as monofunctional vinyl monomers and up to 30% of ethylene glycol dimethacrylate (EGDMA) as multifunctional vinyl monomer. The resultant PEGMEMA-PPGMA-EGDMA copolymers have been characterized by gel permeation chromatography (GPC) and (1)H NMR analysis, which demonstrate their multivinyl functionality and hyperbranched structures. These water-soluble copolymers show lower critical solution temperature (LCST) behavior at 32 degrees C, which is comparable to poly(N-isopropylacrylamide) (PNIPAM). The copolymers can also be cross-linked by photopolymerization through their multivinyl functional groups. Rheological studies clearly demonstrate that the photocrosslinked gels formed at a temperature above the LCST have higher storage moduli than those prepared at a temperature below the LCST. Moreover, the cross-linking density of the gels can be tuned to tailor their porous structures and mechanical properties by adjusting the composition and concentration of the copolymers. Hydrogels with a broad range of storage moduli from 10 to 400 kPa have been produced.