Modulated Composite Nanofibers with Enhanced Structural Stability for Promotion of Hard Tissue Healing

Abstract

While various polyesters have been electrospun into fibrous scaffolds, these constructs lack sufficient strength and osteoconductivity that is usually desired for potential bone tissue engineering. Here, hydroxyapatite (HA), either in the form of traditional nanospheres or in the form of nanorods, was tried to incorporate into a new nanofibrous scaffold based on electrospun poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with a given 3-hydroxyvalerate (HV) content. The rod-like nanoparticles were used, in particular, to closely mimic the natural structure of bone. Since the solubility of polymers is a critical parameter in the electrospinning process, the solubility of PHBV having different HV contents was also examined in different solvents using a combined experimental and theoretical study. According to the results, 1,1,1,3,3,3-hexafluoropropan-2-ol is ideally able to dissolve PHBV with 5% HV content and hence to produce nanofibers with minimal structural defects during the electrospinning process. Moreover, although both the spherical and rod-like particles could be homogeneously embedded in the PHBV at the expected concentration, the addition of rod-like HA to PHBV can result in composite nanofibers with a significantly enhanced structural strength.