Controlled degradation of hydrogels using multi-functional cross-linking molecules
Controlled degradation of hydrogels using multi-functional cross-linking molecules
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DOI：
10.1016/j.biomaterials.2003.09.030
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发表时间：
2004-06-01
期刊：
影响因子：
14
通讯作者：
Mooney, DJ
中科院分区：
文献类型：
--
作者：
Lee, KY;Bouhadir, KH;Mooney, DJ
水凝胶，化学交联或物理缠结，已经发现了许多应用作为药物和细胞的新型递送载体。然而，目前可从许多水凝胶获得的降解速率和机械强度的窄范围限制了它们的应用。我们假设，利用多功能交联分子形成水凝胶可以提供比双功能交联分子更宽的范围和更严格的控制凝胶的降解速率和机械刚度。为了解决这一问题，我们从海藻酸钠中分离出α-L-古洛糖醛酸残基，并将其氧化制备聚（醛古洛糖醛酸）（PAG）。以聚丙烯酰胺-共-酰肼（PAH）为多功能交联分子或己二酸二酰肼（AAD）为双功能交联分子，制备了水凝胶。监测两种PAG凝胶类型的初始性质和降解行为。PAG/PAH水凝胶在降解前表现出更高的机械刚度，并且在相同浓度的交联官能团下，比PAG/AAD凝胶降解更慢。力学刚度的增强和降解行为的延长可能归因于在相同浓度的官能团下，PAH在凝胶中的多个附着点。这种用多功能交联分子调节凝胶性质的方法可广泛用于水凝胶。(C)2003 Elsevier Ltd.保留所有权利。
Hydrogels, chemically cross-linked or physically entangled, have found a number of applications as novel delivery vehicles of drugs and cells. However, the narrow ranges of degradation rates and mechanical strength currently available from many hydrogels limits their applications. We have hypothesized that utilization of multi-functional cross-linking molecules to form hydrogels could provide a wider range and tighter control over the degradation rates and mechanical stiffness of gels than bi-functional cross-linking molecules. To address the possibility, we isolated alpha-L-guluronate residues of sodium alginate, and oxidized them to prepare poly(aldehyde guluronate) (PAG). Hydrogels were formed with either poly(acrylamide-co-hydrazide) (PAH) as a multi-functional cross-linking molecule or adipic acid dihydrazide (AAD) as a bi-functional cross-linking molecule. The initial properties and degradation behavior of both PAG gel types were monitored. PAG/PAH hydrogels showed higher mechanical stiffness before degradation and degraded more slowly than PAG/AAD gels, at the same concentration of cross-linking functional groups. The enhanced mechanical stiffness and prolonged degradation behavior could be attributed to the multiple attachment points of PAH in the gel at the same concentration of functional groups. This approach to regulating gel properties with multifunctional cross-linking molecules could be broadly used in hydrogels. (C) 2003 Elsevier Ltd. All rights reserved.