Network formation and degradation behavior of hydrogels formed by Michael-type addition reactions
Network formation and degradation behavior of hydrogels formed by Michael-type addition reactions
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DOI：
10.1021/bm049607o
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发表时间：
2005-01-01
影响因子：
6.2
通讯作者：
Hubbell, J
中科院分区：
文献类型：
--
作者：
Metters, A;Hubbell, J
水解不稳定的聚（乙二醇）为基础的水凝胶是通过迈克尔型加成反应之间的不饱和丙烯酸酯部分和亲核硫醇。虽然这些凝胶提供了选择性，原位聚合和潜在的生物相容性矩阵的细胞和蛋白质封装的优点，控制这些交联网络的宏观行为之前和水解降解过程中的复杂的结构-性能关系的透彻理解不存在。因此，在这项工作中，提出了一个新的理论模型来描述逐步聚合凝胶的形成和水解降解。该模型解释了水解动力学的变化以及结构效应，如前体功能和初级循环或其他结构非理想性的存在，降低了网络的交联效率。模型预测和实验数据的比较验证了这种优化生物材料设计的方法，并揭示了结构非理想性在确定真实的交联系统的降解行为中起着关键作用。在网络形成期间降低前体浓度和官能度产生高浓度的网络非理想性，其最终导致更高的初始溶胀比和更快的表观降解速率。
Hydrolytically labile poly(ethylene glycol)-based hydrogels are fabricated via a Michael-type addition reaction between unsaturated acrylate moieties and nucleophilic thiols. Although these gels offer the advantage of selective, in situ polymerization and potential as biocompatible matrixes for cell and protein encapsulation, a thorough understanding of the complex structure-property relationships that control the macroscopic behaviors of these cross-linked networks before and during hydrolytic degradation does not exist. Therefore, in this work, a novel theoretical model is presented to describe the formation and hydrolytic degradation of the step-polymerized gels. The model accounts for variations in hydrolysis kinetics as well as structural effects such as precursor functionality and the presence of primary cycles or other structural nonidealities that lower the cross-linking efficiency of the networks. Comparison of model predictions and experimental data validate this methodology for optimizing biomaterial design and reveal that structural nonidealities play a key role in determining the degradation behavior of real cross-linked systems. Decreasing precursor concentration and functionality during network formation generate high concentrations of network nonidealities that ultimately lead to higher initial swelling ratios and faster apparent rates of degradation.