State Key Laboratory of Organic-Inorganic Composites, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, 100029, China.
State Key Laboratory of Organic-Inorganic Composites, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, 100029, China.
Colloids Surf B Biointerfaces. 2021 Aug;204:111785. doi: 10.1016/j.colsurfb.2021.111785. Epub 2021 Apr 24.
Bone is an electrically responsive tissue, so electroactive materials that can deliver electrical cues to bone are helpful for enhancing regeneration under electrical stimulation (ES), and conductive materials are crucial in ES transmission to determine osteogenesis. Compared with polyesters, biodegradable polyorganophosphazenes (POPPs) show superiority in the field of bone tissue engineering thanks to their rich phosphorus/nitrogen contents, suggesting that the combination of POPPs-based conductive substrates with ES may achieve synergistic enhancements on osteogenesis. Herein, conductive composite films were fabricated by blending poly[(alanine ethyl ester)-(glycine ethyl ester)]phosphazene (PAGP) with carbon nanotubes (CNTs). After surface modification with polydopamine (PDA), bone marrow mesenchymal stromal cells (BMSCs) were cultured on the films under ES, using the cells cultured on conductive films composed of poly(L-lactide) (PLLA) and CNTs as controls. The BMSCs on PAGP/CNT films demonstrated significantly faster proliferation rates and stronger osteogenic differentiation potentials than those on PLLA/CNT films, while cell attachments on the two PDA-coated substrates were similar. Under appropriate ES, further increases in the expressions of osteogenic markers as alkaline phosphatase, collagen I and calcium deposition were identified in comparison with the cases without ES. The contributions of the osteocompatible POPPs, the substrate conductivity and the ES treatment to enhanced osteogenesis suggested new strategies for the design of bone repair materials.
骨骼是一种对电反应的组织，因此能够向骨骼传递电信号的电活性材料有助于在电刺激（ES）下增强再生，而导电材料在 ES 传输中对于确定成骨至关重要。与聚酯相比，由于其丰富的磷/氮含量，可生物降解的聚有机磷腈（POPP）在骨组织工程领域表现出优势，这表明基于 POPP 的导电基底与 ES 的结合可能在成骨方面实现协同增强。本文通过将聚[（丙氨酸乙酯）-（甘氨酸乙酯）]磷腈（PAGP）与碳纳米管（CNT）共混来制备导电复合膜。经过聚多巴胺（PDA）表面改性后，在 ES 下将骨髓间充质基质细胞（BMSC）培养在薄膜上，以由聚（L-丙交酯）（PLLA）和 CNT 组成的导电薄膜上培养的细胞作为对照。与 PLLA/CNT 薄膜相比，PAGP/CNT 薄膜上的 BMSC 增殖速度更快，成骨分化潜力更强，而两种 PDA 涂层基底上的细胞附着相似。在适当的 ES 下，与没有 ES 的情况相比，碱性磷酸酶、胶原蛋白 I 和钙沉积等成骨标志物的表达进一步增加。对成骨相容的 POPP、基底导电性和 ES 处理对增强成骨的贡献表明了设计骨修复材料的新策略。
