Fabrication and characterization of hydroxyapatite-strontium/polylactic acid composite for potential applications in bone regeneration

In this study, polylactic acid (PLA) was reinforced with hydroxyapatite (HAp) microparticles and strontium (Sr) powder via the melt extrusion/hot pressing manufacturing process to produce scaffolding materials with bone regeneration potentials. After the fabrication of the materials, the physico-chemical and mechanical characteristics were investigated. The morphology of the precursors for scaffold fabrication and the resulting composites was investigated. The structural characterization showed the semicrystalline nature of the PLA polymer and the characteristic reflections of HAp loading in the polymer matrix. The functional groups of the PLA matrix and the loaded variants showed the characteristic bands of HAp and Sr for the PLA-HAp and PLA-HAp-Sr scaffolding materials, respectively. Moreover, the physical property evaluation showed that with the addition of HAp, the porosity of the PLA-HAp scaffolds was reduced. However, the addition of Sr increased the porosity of the scaffolds, and this can possibly be ascribed to the grain refinement ability of strontium. The mechanical measurement data showed that the inclusion of Sr produced the maximum average Vickers hardness value of 49.1 HV. The composite scaffolds showed bioactivity potentials, thus, they can serve as suitable bone regeneration materials.