In vitro evaluation of osteoblast adhesion, proliferation and differentiation on chitosan-TiO2 nanotubes scaffolds with Ca2 + ions

•CTNTs scaffolds showed improved compressive modulus and reduced degradation rate.•CTNTs scaffolds showed adsorption affinity towards Ca2 + ions.•Adsorption isotherm of Ca2 + ions on CTNTs scaffolds fit with Freundlich isotherm.•CTNTs scaffolds with Ca2 + ions promoted adhesion, growth and differentiation.

Hydrothermally synthesized TiO2 nanotubes (TNTs) were first used as a filler for chitosan scaffold for reinforcement purpose. Chitosan-TNTs (CTNTs) scaffolds prepared via direct blending and freeze drying retained cylindrical structure and showed enhanced compressive modulus and reduced degradation rate compared to chitosan membrane which experienced severe shrinkage after rehydration with ethanol. Macroporous interconnectivity with pore size of 70-230 μm and porosity of 88% were found in CTNTs scaffolds. Subsequently, the functionalization of CTNTs scaffolds with CaCl2 solutions (0.5 mM-40.5 mM) was conducted at physiological pH. The adsorption isotherm of Ca2 + ions onto CTNTs scaffolds fitted well with Freundlich isotherm. CTNTs scaffolds with Ca2 + ions showed high biocompatibility by promoting adhesion, proliferation and early differentiation of MG63 in a non-dose dependent manner. CTNTs scaffolds with Ca2 + ions can be an alternative for bone regeneration.