Thermal, morphological, spectroscopic and biological study of chitosan, hydroxyapatite and wollastonite biocomposites

Abstract

The objective of this work was to investigate the thermal, morphological, spectroscopic and cytotoxicity of hydroxyapatite–wollastonite powders obtained via sol–gel synthesis and of biocomposites chitosan–hydroxyapatite–wollastonite. A mixture of wollastonite, calcium nitrate tetrahydrate and ammonium dihydrogen phosphate with a ratio of 1:2:1.2 or 2:2:1.2, respectively, was produced following drying and heat treatment where the final composite was macerated. These powders were added to a chitosan solution where it was further dried and neutralized. The ceramic loads were used in various ratios. The materials were characterized by TG, DSC, DRX, MEV, FTIR and cytotoxicity. Based on the studied properties, it can be said that the sol–gel process proved to be effective in obtaining hydroxyapatite–wollastonite powders. By TG, it was verified that the thermal stability of the powders increased when a greater percentage of wollastonite was used. For biocomposites with higher percentages of load, there was increase in thermal stability, probably attributed to the higher compaction of the biocomposites when compared to the pure. By DSC, there was a tendency of displacement of the endothermic and exothermic peaks, suggesting that the biocomposite with higher load has greater capacity of retention and interaction stronger with molecules of water, but also has greater thermal stability. The samples present biomaterial potential with prospects of endodontic use, which showed cell viability in L929 fibroblast cell culture above 70.00%.