Fabrication of carbon nanotube (CNT)/poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) nanocomposite films for human mesenchymal stem cell (hMSC) differentiation

Abstract

Carbon nanotube (CNT)/poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) nanocomposite films were fabricated using a solution mixing and evaporation method. The surface morphology, mechanical and electrical properties of these novel hybrid films were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle determination, tensile tests and electrical measurements. Compared to neat PHBHHx, both the surface roughness and the electrical conductivity of the nanocomposites increased, and mechanical properties showed a significant improvement due to the presence of CNTs. The cell compatibility of the nanocomposites was evaluated by human mesenchymal stem cells (hMSCs). The activity and proliferation of hMSCs were demonstrated to be outstanding when nanocomposite films contained 1% CNTs compared with that on the neat PHBHHx. Levels of osteogenesis differentiation on nanocomposite films were assessed through alkaline phosphatase (ALP) activities, calcium contents and specific osteogenesis genes mRNA expressions, which showed that the 1% CNT/PHBHHx composite film was also suitable for osteogenesis of hMSCs. The results indicated that semi-conductive CNT/PHBHHx biomaterials could be a potential candidate in bone tissue engineering.