Preparation and characterization of carbon nanotube-grafted-chitosan - natural hydroxyapatite composite for bone tissue engineering

Porous, biodegradable and biocompatible chitosan, chitosan with natural hydroxyapatite derived from Thunnus Obesus bone (chitosan/HAp) and chitosan grafted with functionalized multiwalled carbon nanotube in addition to HAp (f-MWCNT-g-chitosan/HAp) scaffolds were prepared for the first time via freeze-drying method and physiochemically characterized as bone graft substitutes. The cross-linkages in the novel f-MWCNT-g-chitosan/HAp scaffold were observed by FT-IR spectroscopy. The water uptake, retention ability and degradation of composite scaffolds decreased whereas thermal stability increased with an addition of HAp and f-MWCNT. Uniform dispersion of HAp and f-MWCNT in chitosan matrix with interconnected porosity of 70-200 μm (chitosan/HAp) and 46-200 μm (f-MWCNT-g-chitosan/HAp) was observed by X-ray diffraction, scanning electron microscopy and optical microscopy. Cell proliferation in composite scaffolds was twice than in pure chitosan when checked in vitro using MG-63 cell line. These observations suggest that the novel chitosan/HAp and f-MWCNT-g-chitosan/HAp composite scaffolds are promising biomaterials for bone tissue engineering