Zhu Xiangbo, Chen Taijun, Feng Bo, Weng Jie, Duan Ke, Wang Jianxin, Lu Xiaobo
Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan 610031, P.R. China.
Department of Bone and Joint Surgery, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan 646000, P.R. China.
ACS Biomater Sci Eng. 2018 Oct 8;4(10):3534-3544. doi: 10.1021/acsbiomaterials.8b00682. Epub 2018 Sep 21.
Although hydrogels based on biopolymers show many advantages, their low mechanical properties limit their applications in osteochondral tissue engineering. In this study, one part of our work aimed at preparing a high strength biohydrogel by using a double-network (DN) hydrogel system, which consisted of two interpenetrating polymer networks composed of γ-glutamic acid, lysine, and alginate, and meanwhile by incorporating bacterial cellulose into the DN structures. The results showed that compression modulus of the resultant hydrogel (0.322 MPa) was comparable with that of natural articular cartilage and swelling degree was greatly depressed by using these strategies. On this basis, a bilayer hydrogel scaffold based on the bionics principle for osteochondral regeneration was fabricated via chemical and physical cross-linking. Additionally, hydroxyapatite (HA) particles with two different sizes were introduced into the bilayer hydrogels, respectively: micro-HA in the top layer for promoting cartilage matrix deposition and HA nanocrystals in the bottom layer for enhancing compression modulus and osteogenesis. The osteochondral defect model of rabbits was used to evaluate the repair effect of the scaffolds with the bilayer structure, and the results showed such as-synthesized scaffolds had a good osteochondral repair effect.
尽管基于生物聚合物的水凝胶具有许多优点，但其较低的机械性能限制了它们在骨软骨组织工程中的应用。在本研究中，我们工作的一部分旨在通过使用双网络（DN）水凝胶系统制备高强度生物水凝胶，该系统由由γ-谷氨酸、赖氨酸和藻酸盐组成的两个互穿聚合物网络构成，同时将细菌纤维素掺入DN结构中。结果表明，所得水凝胶的压缩模量（0.322 MPa）与天然关节软骨相当，并且通过使用这些策略，溶胀度大大降低。在此基础上，通过化学和物理交联制备了基于仿生原理用于骨软骨再生的双层水凝胶支架。此外，将两种不同尺寸的羟基磷灰石（HA）颗粒分别引入双层水凝胶中：顶层为微HA以促进软骨基质沉积，底层为HA纳米晶体以提高压缩模量和成骨作用。使用兔骨软骨缺损模型评估具有双层结构的支架的修复效果，结果表明所合成的支架具有良好的骨软骨修复效果。
