胶原自组装与化学交联制备水凝胶及其性能表征

Preparation and characterization of hydrogels based on collagen self-assembly and chemical cross-linking

借助胶原(Col)自组装制备水凝胶并采用氧化羧甲基纤维素钠(OCMC)对其交联改性.红外图谱表明改性前后胶原均具有完整三股螺旋结构.当OCMC∶Col(w/w)≤0.3∶1时,相邻胶原纤维交联形成“纤维单元”,热变性温度(Td)和储能模量(G′)分别从47.0℃、101.3 Pa增加至52.1℃、112.1 Pa;当0.3∶1<OCMC∶Col(w/w)≤5∶1时,交联度提高至43.9%,多个纤维单元进一步交联聚集,Td和G′分别提高7.0℃、23.9 Pa,形变率降低5.1%;当OCMC∶Col(w/w)>5∶1后,交联剂虽翻倍增加,但纤维排列已非常紧密,因此Td、G′及形变率的变化量仅为2.6℃、5.0 Pa和0.1%.

Collagen(Col)hydrogel was prepared via collagen self-assembly and then modified by oxidized sodium carboxymethyl cellulose(OCMC).FT-IR spectra showed that both the uncrosslinked and crosslinked collagens had the complete triple-helical structure.As the ratio of OCMC/collagen was no more than 0.3∶1,the adjacent collagen fibrils were preferentially crosslinked and formed"fibril units".The thermal denaturation temperature(Td)and storage modulus(G′)increased from 47.0℃and 101.3 Pa to 52.1℃and 112.1 Pa,respectively.At 0.3∶1<OCMC∶Col(w/w)≤5∶1,the crosslinking degree increased to 43.9%and the"fibril units"gradually aggregated.As a result,the values of Td and G′increased obviously by 7.0℃and 23.9 Pa,respectively,and the deformation rate decreased by 5.1%.When the ratio of OCMC to collagen was more than 5∶1,although the OCMC amount was doubled,the collagen fibrils had aggregated closely;the variations of Td,G′and deformation rate were only 2.6℃,5.0 Pa and 0.1%,respectively.