Evaluation of the effects of multiwalled carbon nanotubes on electrospun poly(3-hydroxybutirate) scaffold for tissue engineering applications

In this study, regarding the importance of optimal design and unique role of a scaffold in tissue regeneration and repair, poly(hydroxybutyrate) (PHB)/multiwalled carbon nanotubes (CNTs) nanocomposite scaffolds with different samples concentrations of CNTs (0, 0.5, 0.75, 1.0, and 1.25% w/v) was prepared by electrospinning technique. Morphological evaluation of scaffolds by using scanning electron microscopy showed the pore volume in all the scaffolds was over 80% and the addition of CNTs increased the average fiber diameter, from 210 nm (neat PHB) to 500 nm at 1.0% CNTs. To evaluate the structural properties of scaffolds, transmission electron microscopy and Fourier transform infrared spectroscopy were used and showed the presence of CNTs at along the fibers. The analysis of mechanical properties of the PHB/CNTs composites by using universal testing machine revealed great improvement over pure PHB scaffold, so that the tensile stress of the PHB/0.5%CNTs scaffolds was increased by 157%. The bioactivity of scaffolds was analyzed by placing them in simulated body fluid for 4 weeks and results showed that CNTs increase the bioactivity of scaffolds. The wettability of the scaffolds was evaluated with a conventional sessile drop method. The results of contact angles of surface showed that CNTs treatment increases the surface wettability. The attachment ability and viability of osteosarcoma cell lines MG-63 in presence of the scaffolds were also investigated. The attachment and proliferation of MG-63 were significantly increased in the PHB/CNTs scaffolds compared with the PHB control. Therefore, the PHB/CNTs composite scaffolds may be potentially useful in tissue engineering applications.