How geometry,size, and surface properties of tailor-made particles control the efficiency of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/hydroxyapatite nanocomposites

Bioactive calcium phosphate nanoparticles as reinforcing filler have widely been used to produce polymer nanocomposite scaffolds suitable for application in bone tissue engineering; however, no study has investigated the effect of geometry, size, and surface properties of these nanoparticles on physical and mechanical behavior of scaffolds. This study was therefore devoted to determine how the critical features of the reinforcing nanoparticles could tailor the efficiency of polymeric nanocomposites. For this, we developed fibrous nanocomposite systems in which poly(3-hydroxybutyrate-co-3-hydroxyvalerate), PHBV, was combined with hydroxyapatite (HA) nanoparticles having different sizes, geometries, surface chemical groups, and concentrations. The results showed that critical properties could be controlled by incorporating appropriate amounts of nanoparticles with a specific geometry and surface properties. It was also seen that the tensile modulus of fibrous nanocomposite increased from 77 MPa for neat PHBV to about 161 MPa for the nanocomposites containing 15 wt% surface-modified nanoparticles with elongated morphology.