Ko Han-Seung, Lee Sangwoon, Jho Jae Young
School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, Korea.
Nanomaterials (Basel). 2021 Jan 15;11(1):213. doi: 10.3390/nano11010213.
To enhance the bioactivity of poly(lactic acid) (PLA), a potential bone repair material, without the lowering of mechanical strength, hydroxyapatite (HA) was introduced in the form of nanofibers as the filler for application in spinal implant materials. HA nanofibers (HANF) with aspect ratio as high as ~100 were synthesized by controlling the starting pH of the reaction. While the tensile and flexural strength of PLA/HANF composites were enhanced compared with those of PLA resin, and were higher for the composites with HANF of higher aspect ratio. To further strengthen the composites, HANF was grafted with PLA chain to form HANF-g-PLA, which could improve the interface between the HANF and matrix PLA. PLA/HANF-g-PLA composites showed even higher tensile and flexural strength than PLA/HANF composites, apparently due to the better dispersion and interfacial adhesion. The composite containing 10 wt% HANF-g-PLA showed the flexural strength of 124 MPa, which was 25% higher than that of PLA resin. In the bioactivity test using a simulated body fluid solution, the rate and uniformity of the apatite growth were observed to be higher for the composites with HANF, and were even higher for those with HANF-g-PLA. This study suggested the possibility of using the PLA/HANF-g-PLA composite in the field of spinal implant materials.
为了在不降低机械强度的情况下提高聚乳酸（PLA）（一种潜在的骨修复材料）的生物活性，以纳米纤维形式引入羟基磷灰石（HA）作为填充剂应用于脊柱植入材料。通过控制反应起始pH值合成了长径比高达~100的HA纳米纤维（HANF）。与PLA树脂相比，PLA/HANF复合材料的拉伸强度和弯曲强度得到了提高，对于长径比更高的HANF复合材料，其强度更高。为了进一步增强复合材料，将PLA链接枝到HANF上形成HANF-g-PLA，这可以改善HANF与基体PLA之间的界面。PLA/HANF-g-PLA复合材料的拉伸强度和弯曲强度甚至比PLA/HANF复合材料更高，这显然是由于更好的分散性和界面粘附性。含有10 wt% HANF-g-PLA的复合材料弯曲强度为124 MPa，比PLA树脂高25%。在使用模拟体液溶液的生物活性测试中，观察到含有HANF的复合材料磷灰石生长速率和均匀性更高，而含有HANF-g-PLA的复合材料更高。本研究表明了PLA/HANF-g-PLA复合材料在脊柱植入材料领域应用的可能性。
