Development of functionalized multi-walled carbon nanotube-based polysaccharide-hydroxyapatite scaffolds for bone tissue engineering

New tricomponent composite scaffolds with high porosity (82.82% for oxidized carbon nanotube (fMWCNT)-gellan-hydroxyapatite (HAP) and 91.76% for fMWCNT-amylopectin-HAP) were prepared by a freeze drying method and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FE-SEM). Further, their ability to promote cell proliferation of the MG 63 cell line for bone regeneration was studied. In vitro MTT assays with the MG 63 cell line demonstrated better cell proliferation on both the fMWCNT-gellan-HAP and fMWCNT-amylopectin-HAP scaffolds. The cell adhesion of the MG 63 cells on the scaffolds after four days was confirmed by fluorescence imaging using Hoechst and Acridine Orange dye staining. Enhanced mineralization over time was observed in the alkaline phosphatase (ALP) activity. A higher compressive strength (222.60 +/- 8.4 kPa) was observed for fMWCNT-gellan-HAP, when compared to fMWCNT-amylopectin-HAP (57.32 +/- 2.4 kPa). This may be due to the lower porosity of fMWCNT-gellan-HAP. These results ascertained that the prepared tricomponent scaffolds can be used as promising materials in bone tissue engineering.