Physical, mechanical and biological performance of PHB-Chitosan/MWCNTs nanocomposite coating deposited on bioglass based scaffold: Potential application in bone tissue engineering

Abstract

Nowadays, using the nanocomposite coatings on bioceramic scaffolds is a great interest for many researchers to improve the properties of these scaffolds. In this study, the effect of poly (3-hydroxybutyrate) PHB-Chitosan (Cs)/multi-walled carbon nanotubes (MWCNTs) nanocomposite coating deposited on nano-bioglass (nBG)-titania (nTiO₂) scaffolds fabricated by foam replication method was investigated. Structural analyses such as XRD and FT-IR confirmed the presence of PHB, Cs and MWCNTs in the coated scaffolds. The results of SEM and porosity measurement showed that even with 1 wt% MWCNTs, scaffolds have a high percentage of interconnected porosity. The compressive strength of the scaffolds coated with PHB-Cs/MWCNTs (1 wt%) was increased up to 30 folds compared to nBG/nTiO₂ scaffold. The surface roughness of the coated scaffolds, which was determined by AFM, was increased. The nanocomposite coating caused a decrease in contact angle and retaining the negative zeta potential of the coated scaffolds. The increase in pH and degradation rate was observed in the coated scaffolds. Increasing the apatite-like formation by the presence of PHB-Cs/MWCNTs was confirmed by SEM, EDAX and XRD tests. PHB-Chitosan/MWCNTs nanocomposite coating lead to more proliferation and viability of MG-63 cells and higher secretion of alkaline phosphatase.

Keywords: Bioglass; Carbon nanotubes; Chitosan; Polyhydroxybutyrate; Tissue engineering; Titania.