PDF(Pubmed)
Abstract：
Degradable piezoelectric materials possess significant potential for application in the realm of bone tissue regeneration. However, the correlation between cell regulation mechanisms and the dynamic variation caused by material degradation has not been explained, hindering the optimization of material design and its in vivo application. Herein, piezoelectric poly (L-lactic acid) (PLLA) nanofibers with different molecular weights (MW) were fabricated, and the effects of their piezoelectric properties, structural morphology, and material products during degradation on the adhesion and osteogenic differentiation of mesenchymal stem cells (MSCs) were investigated. Our results demonstrated that cell adhesion-mediated piezoelectric stimulation could significantly enhance cell spreading, cell orientation, and upregulate the expression of calmodulin, which further triggers downstream signaling cascade to regulate osteogenic differentiation markers of type I collagen and runt-related transcription factor 2. Additionally, during the degradation of the nanofibers, the piezoelectric properties of PLLA weakened, the fibrous structure gradually diminished, and pH levels in the vicinity decreased, which resulting in reduced osteogenic differentiation capability of MSCs. However, nanofibers with higher MW (280 kDa) have the ability to maintain the fibrous morphology and piezoelectricity for a longer time, which can regulate the osteogenic differentiation of stem cells for more than 4 weeks. These findings have provide a new insight to correlate cell behavior with MW and the biodegradability of piezopolymers, which revealed an active method for cell regulation through material optimization for bone tissue engineering in near future.
摘要：
可降解压电材料在骨组织再生领域具有巨大的应用潜力。然而,细胞调节机制与物质降解引起的动态变化之间的相关性尚未得到解释，阻碍了材料设计的优化及其在体内的应用。在这里，制备了不同分子量(MW)的压电聚(L-乳酸)(PLLA)纳米纤维,以及它们的压电特性的影响，结构形态，研究了降解过程中材料产物对间充质干细胞(MSCs)的黏附和成骨分化的影响。我们的结果表明，细胞粘附介导的压电刺激可以显着增强细胞扩散，细胞取向,并上调钙调蛋白的表达，这进一步触发下游信号级联，以调节I型胶原蛋白和runt相关转录因子2的成骨分化标志物。此外,在纳米纤维的降解过程中，PLLA的压电性能减弱，纤维结构逐渐减弱，附近的pH值下降，导致MSCs成骨分化能力降低。然而,具有较高MW（280kDa）的纳米纤维具有更长时间保持纤维形态和压电性的能力，可以调节干细胞的成骨分化4周以上。这些发现为将细胞行为与分子量和压电聚合物的生物降解性相关联提供了新的见解。在不久的将来，通过材料优化为骨组织工程揭示了一种积极的细胞调控方法。
