Structural, mechanical, and in-vitro characterization of hydroxyapatite loaded PLA composites

This article is intended to present an optimized Biocomposites material to prepare customized implants by using additive manufacturing technology. The most preferred implant material, polylactic acid (PLA) and hydroxyapatite (HAp), is chosen as matrix and reinforcements with different weight percentages of reinforcements. The 3D-printed composites underwent structural, mechanical, thermal stability, and in-vitro characterization. In the composites, the functional groups "OH, C-H, C--O, C-O, and PO4" identified by Fourier transform infrared spectroscopy (FTIR). The thermal stability of the composites was identified by Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). For the composition of PLA-HAp, a maximum tensile strength of 62 +/- 0.5 MPa (30 wt%), a maximum compressive strength of 61 +/- 0.5 MPa at 50 wt%), a maximum flexural strength of 46 +/- 0.5 MPa (20 wt%), and a Shore-D hardness of 82 +/- 0.5 SHN (50 wt%) were obtained. Modeled maximal principal stress in PLA and HAp. The 30 wt% of HAp-PLA composite carried out the in-vitro direct cytotoxicity, and it revealed 97% cell viability and 3% cytotoxicity through the L929 cell line. The results indicate that the addition of reinforcement increased the mechanical strength and cell visibility; therefore, the HAp-PLA composite would be used in biomedical applications.