In vitro characterization of a biocompatible composite based on poly(3-hydroxybutyrate)/hydroxyapatite nanoparticles as a potential scaffold for tissue engineering.

The use of regeneration scaffolds has been a promising strategy in the bone tissue engineering area. Among the materials available for this purpose the poly(3-hydroxybutyrate) - PHB stands out for its adequate biocompatibility and osteoinduction capacity. Hydroxyapatite, in turn, has as its main characteristics its ability to increase bioactivity and cell proliferation. Thus, the objective of the present study was to obtain PHB composites with nanohydroxyapatite (Hap) (0.05%, 0.20%, and 0.50%) and evaluate the microstructure, thermal and mechanical properties and molecular dynamics. Besides that, in vitro biological properties such as wettability, cell viability and adhesion of L929 fibroblasts cells, enzymatic degradation and radiographic contrast were evaluated. The results indicate a weak interaction between Hap and PHB, however, the dispersion states of the nanoparticles can influence crystallization and thermal stability. Through the evaluation of the mechanical behavior was verified a harder behavior with the Hap addition. The wettability of the systems showed a tendency to increase with the addition of nanoparticles. All systems presented high values of viability and cell adhesion, the latter being more pronounced for systems containing Hap. The nanoparticles acted as a barrier slowing the rate of enzymatic degradation and contributed to the increase in radiographic contrast. The results obtained indicate that the systems are promising for application in tissue engineering.