Effect of HA/PVA Composition on the Microstructure and Mechanical Properties of Porous Hydroxyapatite Scaffolds Fabricated Using the Polyurethane Sponge Replication Method

Abstract

Hydroxyapatite is acknowledged as a valuable biomaterial for bone tissue engineering because of its outstanding biocompatibility and resemblance to natural bone. Nonetheless, attaining an ideal equilibrium between porosity and mechanical strength in porous HA scaffolds continues to be difficult. This research examines how different HA/PVA ratios (85/15, 80/20, and 75/25) influence the structural and mechanical characteristics of porous hydroxyapatite scaffolds created through the polyurethane sponge replication technique. The scaffolds were subjected to sintering at 900 °C and then coated with 15 wt% gelatin to enhance structural stability and interparticle adhesion. Scanning electron microscopy and X-ray diffraction were utilized for microstructural and phase analyses, and porosity, density, and compressive strength were assessed to evaluate scaffold performance. The findings suggest that the HA/PVA mixture greatly influences the structure and mechanical properties of the scaffold. The 80/20 HA/PVA ratio demonstrated the best performance, yielding a compressive strength of 2.48 MPa, a density of 6.842 g/cm³, and a porosity close to 56%, along with a highly interconnected porous structure. The gelatin layer enhanced structural stability by minimizing microcrack development and reinforcing the scaffold structure. Moreover, micropores averaging 2.378 µm in size were detected, suggesting their likely appropriateness for applications in tissue integration and bone regeneration.