Development and characterization of PLA/hydroxyapatite/TiO₂ biocomposites: Mechanical, physicochemical, and degradation properties

Biodegradable polymer composites have emerged as promising materials for biomedical applications, particularly in bone repair and regenerative medicine. Among these, polylactic acid (PLA) has gained considerable attention due to its biocompatibility, biodegradability, and ease of processing. However, its clinical application is limited by brittleness, low mechanical strength, and poor bioactivity. To address these limitations, in this study, hydroxyapatite (HA) and titanium dioxide (TiO₂) were incorporated into the PLA matrix to develop PLA/HA and PLA/HA/TiO₂ composites using a solvent casting method combined with ultrasonication, with varying HA (2–6 wt%) and TiO₂ (0.25–1 wt%) contents. The developed composites were systematically characterized using FESEM, XRD, and FTIR to analyze morphology, phase composition, and chemical interactions. Mechanical and physicochemical properties were evaluated using tensile testing, hardness analysis, surface roughness, water uptake, contact angle, and in vitro biodegradation studies. The results demonstrated that the incorporation of HA improved tensile strength (up to 28% at 4 wt% HA), hardness, and hydrophilicity, while reducing water absorption. The addition of TiO₂ further enhanced mechanical performance and interfacial bonding, with optimal results observed at 0.50 wt% TiO₂. Biodegradation studies revealed improved stability of the composites compared to neat PLA, while maintaining favorable degradation characteristics. Overall, the developed PLA/HA/TiO₂ biocomposites exhibit moderate mechanical, structural, and functional properties and can be considered for non-load-bearing bone tissue engineering scaffolds, guided bone regeneration matrices, and temporary resorbable support materials, where biodegradability, surface bioactivity, and controlled degradation are more important than high structural strength.