BIOERODIBLE HYDROGELS BASED ON PHOTOPOLYMERIZED POLY(ETHYLENE GLYCOL)-CO-POLY(ALPHA-HYDROXY ACID) DIACRYLATE MACROMERS
BIOERODIBLE HYDROGELS BASED ON PHOTOPOLYMERIZED POLY(ETHYLENE GLYCOL)-CO-POLY(ALPHA-HYDROXY ACID) DIACRYLATE MACROMERS
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DOI：
10.1021/ma00056a005
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发表时间：
1993-02-15
期刊：
影响因子：
5.5
通讯作者：
HUBBELL, JA
中科院分区：
文献类型：
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作者：
SAWHNEY, AS;PATHAK, CP;HUBBELL, JA
合成了具有聚（乙二醇）中心嵌段的大分子单体，其用α-羟基酸的低聚物如低聚（dl-乳酸）或低聚（乙醇酸）延伸并用丙烯酸酯基团封端，并以获得生物可蚀性水凝胶为目标进行表征，所述水凝胶可以通过大分子单体的水溶液的光聚合与组织或蛋白质直接接触而形成。确定这些大分子单体的PEG组分必须大于约55摩尔%以提供水溶性。大分子单体的两亲性使它们呈现胶束构象，这使它们能够进行快速光聚合。由于大分子单体的多功能性，聚合导致交联凝胶的形成。这些凝胶在低聚（α-羟基酸）区域水解成聚（乙二醇）、α-羟基酸和低聚（丙烯酸）后降解。这些凝胶的降解速率可以通过适当选择低聚（α-羟基酸）来定制，从少于1天到长达4个月。使用无毒的光引发剂，大分子聚合物可以在与组织直接接触的情况下用可见光快速光聚合，而没有过度加热或局部毒性。如果在与组织接触时聚合，则凝胶可能通过相互渗透粘附在组织上;如果在与组织接触前聚合，则凝胶非常不粘附，可能是由于含有大量游离水，这些游离水不与乙二醇聚合物的醚键形成氢键。这些新型材料适用于许多生物医学应用，并显示出在大分子药物递送中的潜在用途。
Macromers having a poly(ethylene glycol) central block, extended with oligomers of alpha-hydroxy acids such as oligo(dl-lactic acid) or oligo(glycolic acid) and terminated with acrylate groups, were synthesized and characterized with the goal of obtaining a bioerodible hydrogel that could be formed in direct contact with tissues or proteins by photopolymerization of aqueous solutions of the macromer. It was determined that the PEG component of these macromers must be greater than approximately 55 mol % to provide water solubility. The amphiphilic nature of the macromers causes them to assume a micellar conformation, which enables them to undergo rapid photopolymerization. Due to the multifunctionality of the macromers, polymerization results in the formation of cross-linked gels. These gels degrade upon hydrolysis of the oligo(alpha-hydroxy acid) regions into poly(ethylene glycol), the alpha-hydroxy acid, and oligo(acrylic acid). The degradation rates of these gels can be tailored by appropriate choice of the oligo(alpha-hydroxy acid) from less than 1 day to up to 4 months. Using non toxic photoinitiators, the macromers can be rapidly photopolymerized with visible light in direct contact with tissues without excess heating or local toxicity. If polymerized in contact with tissues, the gels adhere to the tissues, presumably by interpenetration; if polymerized prior to contact with tissues, the gels are very nonadhesive, presumably by possession of a large amount of free water which is not hydrogen bonded with the ether linkages of the ethylene glycol mers. These novel materials are suitable for a number of biomedical applications and show potential for use in macromolecular drug delivery.