Compared Biocompatibility of ZnTiO3, ZnO and TiO2 Sol-Gel Films with Human Mesenchymal Stem Cells

Abstract

ABSTRACTThe biomedical applications of ZnO are drastically limited by its intrinsic solubility, which shortens the stability and lifetime of devices. We show that the functionality of ZnO in human mesenchymal stem cell (hMSC) studies is limited due to poor cell adhesion. The sol-gel route has been employed to obtain zinc titanate thin films for their integration as surface protective layer on ZnO. These films were obtained from zinc acetate (ZnAc) and titanium isopropoxide (TIPT). So derived xerogels were dried and their thermal evolution studied by TGM-DTA to identify critical annealing temperatures. The evolution of the microstructure and composition of spun cast films was determined by XRD and FTIR. Organic and ionic byproducts were eliminated at T>300°C, which kickstarts a transformation of the amorphous materials into polycrystalline. Thin films consisted of the ZnTiO3 perovskite from annealing temperatures of 500°C. Cell adhesion on the synthesized samples (both amorphous and crystalline) was assayed by culturing hMSCs. Immunofluorescence images of actin cytoskeleton were obtained and proliferation studied using Ki67. Cell density, single cell area and proliferation rates on ZnTiO3 films were closer to control TiO2 surfaces than to ZnO films. Such behavior validates the short term biocompatibility of ZnTiO3 films and its potential use as surface layer for ZnO biomedical devices.