The Effect of Hydroxyapatite Inclusion on the Chemical, Physical and Biological Properties of...

This study focuses on the development and comprehensive evaluation of the physicochemical, mechanical, and biological properties of composites based on polyhydroxybutyrate (PHB), chitosan (Ch), and hydroxyapatite (HA) for biomedical applications. DSC and FTIR spectroscopy showed that the addition of hydroxyapatite did not significantly affect the structure of the materials, but AFM data revealed a change in the surface morphology. Variations in RMS roughness ranging from 13 to 150 nm were observed for chitosan and the composites. The density of the HA-containing samples was 0.06-0.067 g/cm³, which is higher than that of the unfilled composite (0.056 g/cm³). Optimal hydrophilic properties (contact angle 38.9°) and elasticity (damping factor 0.064) were recorded for the sample with 10% HA (PChHA10). The water absorption varied: the addition of chitosan increased the value to 7.5 g/g, compared to 2.7 g/g for pure PHB, while HA slowed the swelling kinetics (more than 180 min). A biodegradation study revealed that samples containing 10-20% HA exhibited the highest stability in an enzymatic environment, while further increases in HA content resulted in increased degradation rates. The PChHA10 is considered to offer the balanced combination of properties. The potential applications of this material in medicine include its use as a scaffold for the in vitro cultivation of osteoblasts and chondrocytes, as well as for implantation in models of bone and cartilage defects in vivo.