Cross-linking and degradation of step-growth hydrogels formed by thiol-ene photoclick chemistry.
Cross-linking and degradation of step-growth hydrogels formed by thiol-ene photoclick chemistry.
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DOI：
10.1021/bm300752j
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发表时间：
2012-07-09
影响因子：
6.2
通讯作者：
Lin, Chien-Chi
中科院分区：
文献类型：
--
作者：
Shih, Han;Lin, Chien-Chi
硫醇 - 烯光点击水凝胶已被用于多种组织工程和控释应用。在这种逐步增长的光聚合体系中，多臂聚乙二醇降冰片烯（PEG4NB）与含二硫醇的交联剂交联，形成化学交联水凝胶。虽然硫醇 - 烯凝胶化的机制在文献中有详细描述，但其网络理想性和降解行为却未得到充分表征。在此，我们将硫醇 - 烯水凝胶的网络交联情况与迈克尔加成型水凝胶进行了比较，发现硫醇 - 烯水凝胶形成的凝胶点更快，交联程度更高。然而，硫醇 - 烯水凝胶仍存在显著的网络非理想性，这表现为水凝胶溶胀对大分子单体含量的高度依赖性。此外，PEG - 降冰片烯大分子单体中酯键的存在使硫醇 - 烯水凝胶可发生水解降解。通过将模型预测与实验结果进行验证，我们发现硫醇 - 烯水凝胶的水解降解不仅受酯键水解的控制，还受网络交联程度的影响。为了调控硫醇 - 烯水凝胶的网络交联和降解，我们引入了不同序列的肽交联剂，并对这些PEG - 肽水凝胶的水解降解进行了表征。此外，我们将一种对胰凝乳蛋白酶敏感的肽作为交联剂的一部分，以将凝胶的降解模式从本体降解转变为表面侵蚀。
Thiol-ene photo-click hydrogels have been used for a variety of tissue engineering and controlled release applications. In this step-growth photopolymerization scheme, multi-arm poly(ethylene glycol) norbornene (PEG4NB) was crosslinked with di-thiol containing crosslinkers to form chemically crosslinked hydrogels. While the mechanism of thiol-ene gelation was well described in the literature, its network ideality and degradation behaviors are not well-characterized. Here, we compared the network crosslinking of thiol-ene hydrogels to Michael-type addition hydrogels and found thiol-ene hydrogels formed with faster gel points and higher degree of crosslinking. However, thiol-ene hydrogels still contained significant network non-ideality, demonstrated by a high dependency of hydrogel swelling on macromer contents. In addition, the presence of ester bonds within the PEG-norbornene macromer rendered thiol-ene hydrogels hydrolytically degradable. Through validating model predictions with experimental results, we found that the hydrolytic degradation of thiol-ene hydrogels was not only governed by ester bond hydrolysis, but also affected by the degree of network crosslinking. In an attempt to manipulate network crosslinking and degradation of thiol-ene hydrogels, we incorporated peptide crosslinkers with different sequences and characterized the hydrolytic degradation of these PEG-peptide hydrogels. In addition, we incorporated a chymotrypsin-sensitive peptide as part of the crosslinkers to tune the mode of gel degradation from bulk degradation to surface erosion.
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影响因子：
10.8
作者：
Anseth, KS;Metters, AT;Bowman, CN
通讯作者：
Bowman, CN
影响因子：
14
作者：
Benton, Julie A.;Fairbanks, Benjamin D.;Anseth, Kristi S.
通讯作者：
Anseth, Kristi S.
影响因子：
3.7
作者：
Lin, CC;Metters, AT
通讯作者：
Metters, AT
影响因子：
3.7
作者：
Lin CC;Anseth KS
通讯作者：
Anseth KS
DOI：
10.1073/pnas.0737381100
发表时间：
2003-04-29
影响因子：
11.1
作者：
Lutolf, MP;Lauer-Fields, JL;Hubbell, JA
通讯作者：
Hubbell, JA