School of Material Science and Engineering of Xihua University, Chengdu 610039, China.
Sichuan Institute for Drug Control, Chengdu 610017, China.
Int J Biol Macromol. 2024 Nov;280(Pt 4):136189. doi: 10.1016/j.ijbiomac.2024.136189. Epub 2024 Oct 1.
Despite the exceptional biocompatibility and degradability of Poly (-lactic acid) (PLLA), its brittleness, low melting strength, and poor bone induction makes it challenging to utilize for bone repair. This study used a simple, efficient solid hot drawing (SHD) method to produce high-strength PLLA, using supercritical CO (SC-CO) foaming technology to give PLLA a bionic microporous structure to enhance its toughness, while precisely controlling micropore homogeneity and improving the melt strength by using Polydimethylsiloxane (PDMS). This PDMS-regulated oriented microporous structure resembled that of natural bone, displaying a maximum tensile strength of 165.9 MPa and a maximum elongation at break of 164.2 %. Furthermore, this bionic structure promoted the polarization of mouse bone marrow macrophages (iBMDM), exhibiting a simultaneous pro- and anti-inflammatory effect. This structure also contributed to the adhesion and growth of mouse embryonic fibroblasts (NIH-3 T3), promoting osteogenic differentiation, which paved the way for developing degradable PLLA bone-repair load-bearing materials.
尽管聚（乳酸）（PLLA）具有出色的生物相容性和可降解性，但它的脆性、低熔融强度和较差的骨诱导性使其难以用于骨修复。本研究使用简单、高效的固相反拉（SHD）方法生产高强度 PLLA，使用超临界 CO（SC-CO）发泡技术为 PLLA 赋予仿生微孔结构，以提高其韧性，同时通过聚二甲基硅氧烷（PDMS）精确控制微孔均匀性并提高熔融强度。这种 PDMS 调节的定向微孔结构类似于天然骨，表现出 165.9 MPa 的最大拉伸强度和 164.2%的最大断裂伸长率。此外，这种仿生结构促进了小鼠骨髓巨噬细胞（iBMDM）的极化，表现出同时的促炎和抗炎作用。这种结构还有助于小鼠胚胎成纤维细胞（NIH-3T3）的黏附和生长，促进成骨分化，为开发可降解 PLLA 骨修复承重材料铺平了道路。
