Department of Pharmaceutical and Bioengineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, China.
J Biomed Mater Res A. 2013 Feb;101(2):385-93. doi: 10.1002/jbm.a.34338. Epub 2012 Jul 30.
Polymeric genipin macromers, prepared by ring-opening polymerization at various pH values, are used as crosslinking agents to fix collagen hydrogels. The results indicate that as the dark color of polymeric genipin itself and the networks formed by long-range intermolecular crosslinking, the genipin-fixed collagen hydrogels displace darker color. The polymeric genipin prepared at higher pH value needs longer time to fully crosslink with collagen molecules. Moreover, polymerization of genipin reduces the yield of genipin-fixed collagen hydrogels due to low extent of crosslinking. Specially, the microscope photographs present the porous networks structures of genipin-fixed collagen hydrogels. The pore size increases with the increase in polymerization degree of genipin. The data of FTIR indicate the likely transition of -NH(2) groups in collagen chains into C=N. Owning to much more number of hydrophilic groups and more porous networks, collagen hydrogels fixed by genipin with higher polymerization degree have higher water absorption capacity. The equilibrium swelling of genipin-fixed collagen hydrogels is pH-responsive, which show "M" type changes with the pH values. The results obtained in the study suggest that the polymeric genipin prepared at various pH values lead to significant influence to the crosslinking characteristics and properties of collagen hydrogels.
聚合法尼泊金大分子单体在不同 pH 值下开环聚合，用作交联剂固定胶原水凝胶。结果表明，由于聚合法尼泊金本身的深颜色和长程分子间交联形成的网络，固定化的胶原水凝胶颜色变深。在较高 pH 值下制备的聚合法尼泊金需要更长的时间才能与胶原分子充分交联。此外，由于交联程度低，法尼泊金的聚合降低了固定化胶原水凝胶的产率。特别地，显微镜照片呈现了法尼泊金固定化胶原水凝胶的多孔网络结构。随着法尼泊金聚合度的增加，孔径增大。FTIR 数据表明胶原链中的 -NH(2) 基团可能转化为 C=N。由于具有更多数量的亲水基团和更多的多孔网络，用聚合度较高的法尼泊金固定的胶原水凝胶具有更高的吸水率。固定化胶原水凝胶的平衡溶胀对 pH 值具有响应性，随着 pH 值的变化呈现"M"型变化。研究结果表明，不同 pH 值下制备的聚合法尼泊金对胶原水凝胶的交联特性和性能有显著影响。
