College of Materials, Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, Sichuan, P. R. China.
College of Chemistry, Sichuan University, Chengdu 610064, China.
J Mater Chem B. 2021 Nov 17;9(44):9191-9203. doi: 10.1039/d1tb01554k.
Traditional shape memory polymers (SMPs) could avoid large volume trauma during implantation; however, for bone repair, scaffolds with high porosity and biomineralization are essential to promote bone regeneration. A novel porous composite scaffold with high biomineralization activity was developed by sequential gas foaming and a freeze-drying method. The results showed that the cross-linked block structure of the polymer matrix presented excellent shape memory properties, and osteogenesis was promoted by citrate functionalized amorphous calcium phosphate (CCACP). CCACP improved the mechanical strength of the scaffold, and the synergistic effect of CCACP and PEG promotes hydrophilicity and further promoted cell adhesion. Bending experiments indicated that the shape-memory effect of the scaffolds could be varied by varying the CCACP content. In addition, hydroxyapatite deposition was sped up as CCACP accelerated the mineralization of the scaffolds. Moreover, the result of the CCK-8 assessment suggested that composite scaffolds exhibited high biocompatibility, and the cells extended out abundant filopodia to adhere onto the scaffolds. In rat bone defect models, the obtained scaffolds promoted new bone formation compared to the control group. The developed composite scaffolds show potential for minimally invasive bone repair application.
传统形状记忆聚合物（SMPs）在植入过程中可以避免大体积的创伤；然而，对于骨修复，具有高孔隙率和生物矿化的支架对于促进骨再生至关重要。通过顺序气体发泡和冷冻干燥方法开发了具有高生物矿化活性的新型多孔复合支架。结果表明，聚合物基质的交联嵌段结构表现出优异的形状记忆性能，柠檬酸功能化无定形磷酸钙（CCACP）促进了成骨。CCACP 提高了支架的机械强度，CCACP 和 PEG 的协同作用提高了亲水性，并进一步促进了细胞黏附。弯曲实验表明，通过改变 CCACP 的含量可以改变支架的形状记忆效应。此外，CCACP 加速了支架的矿化，从而加快了羟基磷灰石的沉积。此外，CCK-8 评估的结果表明，复合支架表现出较高的生物相容性，细胞伸出丰富的丝状伪足附着在支架上。在大鼠骨缺损模型中，与对照组相比，获得的支架促进了新骨的形成。开发的复合支架具有微创骨修复应用的潜力。
