Abstract：
Low mechanical strength is still the key question for collagen hydrogel consisting of nanofibrils as hard tissue repair scaffolds with no loss of biological function. In this work, novel collagen nanofibrous hydrogels with high mechanical strength were fabricated based on the pre-protection of trisodium citrate masked Zr(SO4)2 solution for collagen self-assembling nanofibrils and then further coordination with Zr(SO4)2 solution. The mature collagen nanofibrils with d-period were observed in Zr(IV) mediated collagen hydrogels by AFM when the Zr(IV) concentration was ≥ 10 mmol/L, and the distribution of zirconium element was uniform. Due to the coordination of Zr(IV) with ─COOH, ─NH2 and ─OH within collagen and the tighter entanglement of collagen nanofibrils, the elastic modulus and compressive strength of Zr(IV) mediated collagen nanofibrous hydrogel were 208.3 and 1103.0 kPa, which were approximate 77 and 12 times larger than those of pure collagen hydrogel, respectively. Moreover, the environmental stability such as thermostability, swelling ability and biodegradability got outstanding improvements and could be regulated by Zr(IV) concentration. Most importantly, the resultant hydrogel showed excellent biocompatibility and even accelerated cell proliferation.
摘要：
低机械强度仍然是由纳米原纤维组成的胶原水凝胶作为硬组织修复支架而不损失生物学功能的关键问题。在这项工作中,基于柠檬酸三钠掩蔽的Zr（SO4）2溶液对胶原蛋白自组装纳米原纤维的预保护，然后与Zr（SO4）2溶液进一步配位，制备了具有高机械强度的新型胶原蛋白纳米纤维水凝胶。当Zr（IV）浓度≥10mmol/L时，通过AFM在Zr（IV）介导的胶原水凝胶中观察到具有d周期的成熟胶原纳米原纤维，锆元素分布均匀。由于Zr（IV）与─COOH的配位，胶原蛋白内的NH2和OH以及胶原蛋白纳米原纤维的紧密缠结，Zr(IV)介导的胶原纳米纤维水凝胶的弹性模量和抗压强度分别为208.3和1103.0kPa,大约是纯胶原水凝胶的77和12倍，分别。此外，环境稳定性，如热稳定性，溶胀能力和生物降解能力得到了显着改善，并且可以通过Zr（IV）浓度进行调节。最重要的是,所得水凝胶显示出优异的生物相容性，甚至加速细胞增殖。
