State Key Laboratory of Organic-Inorganic Composites, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing, 100029, People's Republic of China.
School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington, 99164.
J Biomed Mater Res A. 2019 Jul;107(7):1443-1454. doi: 10.1002/jbm.a.36659. Epub 2019 Mar 4.
The strategy of using conductive materials in regenerating bone defects is attractive, benefiting from the bioelectricity feature of natural bone tissues. Thereby, POP conductive fibers were fabricated by coating polypyrrole (PPY) onto electrospun poly(l-lactide) (PLLA) fibers, and their potentials in promoting osteogenic differentiation of bone mesenchymal stromal cells (BMSCs) were investigated. Different from the smooth-surfaced PLLA fibers, POP fibers were rough-surfaced and favorable for protein adsorption and mineralization nucleation. When electrical stimulation (ES) was applied, the surface charges on the conductive POP fibers further promoted the protein adsorption and the mineral deposition, while the non-conductive PLLA fibers displayed no such promotion. When BMSCs were cultured on these fibers, strong cell viability was detected, indicating their good biocompatibility and cell affinity. In osteogenic differentiation studies, BMSCs demonstrated the strongest ability in differentiating toward osteoblasts when they were cultured on the POP fibers under ES, followed by the case without ES. In comparison with the conductive POP fibers, the non-conductive PLLA fibers displayed significantly weaker ability in inducing the osteogenic differentiation of BMSCs with ES being applied or not. Alongside the differentiation, both the calcium deposition on BMSC/material complexes and the intracellular Ca concentration were identified the most abundant when BMSCs grew on the POP fibers under ES. These findings suggested that the surface charges of conductive fibers played roles in regulating protein adsorption, ion migration and nucleation, particularly under ES, which contributed much to the increased intracellular Ca ions, and thus accelerated the osteogenic differentiation of the seeded cells. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2019.
利用导电材料修复骨缺损的策略很有吸引力，这得益于天然骨组织的生物电特性。因此，通过将聚吡咯（PPY）涂覆到静电纺丝的聚（L-丙交酯）（PLLA）纤维上，制备了 POP 导电纤维，并研究了它们促进骨髓间充质干细胞（BMSCs）成骨分化的潜力。与光滑表面的 PLLA 纤维不同，POP 纤维具有粗糙表面，有利于蛋白质吸附和矿化核的形成。施加电刺激（ES）时，导电 POP 纤维表面的电荷进一步促进了蛋白质的吸附和矿物质的沉积，而不导电的 PLLA 纤维则没有这种促进作用。当 BMSCs 在这些纤维上培养时，检测到很强的细胞活力，表明它们具有良好的生物相容性和细胞亲和性。在成骨分化研究中，当 BMSCs 在 ES 下培养在 POP 纤维上时，其向成骨细胞分化的能力最强，其次是没有 ES 的情况。与导电的 POP 纤维相比，施加或不施加 ES 时，不导电的 PLLA 纤维诱导 BMSCs 成骨分化的能力明显较弱。伴随着分化，当 BMSCs 在 ES 下生长在 POP 纤维上时，BMSC/材料复合物上的钙沉积和细胞内 Ca 浓度被鉴定为最丰富的。这些发现表明，导电纤维的表面电荷在调节蛋白质吸附、离子迁移和成核方面发挥了作用，尤其是在 ES 下，这有助于增加细胞内 Ca 离子，从而加速了种子细胞的成骨分化。© 2019 年 Wiley 期刊出版公司。J 生物医学材料研究 A 部分，2019 年。
