In the present study, poly(3-hydroxybutyrate)-based composite scaffolds were prepared with multi-walled carbon nanotubes and hydroxyapatite nanoparticles for hard tissue engineering applications by electrospinning. All the prepared scaffolds showed connective porous structure, which were suitable for cell proliferation and migration. The mechanical properties of the poly(3-hydroxybutyrate) scaffold were improved by 0.5% of carbon nanotube addition, whereas the addition of hydroxyapatite nanoparticles up to 10% had an insignificant effect in tensile strength. However, scanning electron microscopy and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay results suggested that the mesenchymal stem cells attachment and their metabolic activities on the surface of the poly(3-hydroxybutyrate) scaffolds with hydroxyapatite were enhanced compared to poly(3-hydroxybutyrate) scaffolds. In addition, after 6 weeks of in vivo biocompatibility results in a model of rat indicated better tissue reactions for the scaffolds that contained hydroxyapatite. Overall, poly(3-hydroxybutyrate) composite scaffolds with 10% hydroxyapatite and 0.5% carbon nanotube showed optimal performances for the potential scaffold for hard tissue engineering application.
