Kim Jung Soo, Choi Jaeho, Ki Chang Seok, Lee Ki Hoon
Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul, South Korea.
Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, South Korea.
Front Bioeng Biotechnol. 2021 Mar 24;9:653509. doi: 10.3389/fbioe.2021.653509. eCollection 2021.
Since articular cartilage does not regenerate itself, researches are underway to heal damaged articular cartilage by applying biomaterials such as a hydrogel. In this study, we have constructed a dual-layer composite hydrogel mimicking the layered structure of articular cartilage. The top layer consists of a high-density PEG hydrogel prepared with 8-arm PEG and PEG diacrylate using thiol-norbornene photo-click chemistry. The compressive modulus of the top layer was 700.1 kPa. The bottom layer consists of a low-density PEG hydrogel reinforced with a 3D silk fiber construct. The low-density PEG hydrogel was prepared with 4-arm PEG using the same cross-linking chemistry, and the compressive modulus was 13.2 kPa. Silk fiber was chosen based on the strong interfacial bonding with the low-density PEG hydrogel. The 3D silk fiber construct was fabricated by moving the silk fiber around the piles using a pile frame, and the compressive modulus of the 3D silk fiber construct was 567 kPa. The two layers were joined through a covalent bond which endowed sufficient stability against repeated torsions. The final 3D silk fiber construct embedded dual-layer PEG hydrogel had a compressive modulus of 744 kPa. Chondrogenic markers confirmed the chondrogenic differentiation of human mesenchymal stem cells encapsulated in the bottom layer.
由于关节软骨无法自行再生，目前正在进行相关研究，试图通过应用水凝胶等生物材料来修复受损的关节软骨。在本研究中，我们构建了一种模仿关节软骨分层结构的双层复合水凝胶。顶层由使用硫醇-降冰片烯光点击化学法，用八臂聚乙二醇（PEG）和聚乙二醇二丙烯酸酯制备的高密度PEG水凝胶组成。顶层的压缩模量为700.1千帕。底层由用三维丝纤维构建体增强的低密度PEG水凝胶组成。低密度PEG水凝胶是用四臂PEG采用相同的交联化学法制备的，其压缩模量为13.2千帕。选择丝纤维是基于其与低密度PEG水凝胶的强界面结合力。三维丝纤维构建体是通过使用桩架将丝纤维绕桩移动而制成的，三维丝纤维构建体的压缩模量为567千帕。两层通过共价键连接，赋予了其足够的稳定性以抵抗反复扭转。最终嵌入双层PEG水凝胶的三维丝纤维构建体的压缩模量为744千帕。软骨生成标记物证实了封装在底层的人间充质干细胞的软骨生成分化。
