Preparation of sodium chitosan phosphate/zinc oxide complexes for periodontal dressing application

Abstract

Sodium chitosan phosphate/zinc oxide complexes were prepared by mixing zinc oxide powder to sodium chitosan phosphate aqueous solution. Mole ratios of sodium chitosan phosphate to zinc oxide were varied in the range of 1:0.25-2. The possible structure of the metal complexes were characterized by FTIR, XRD, TGA and DSC. Surface morphology was observed by SEM. Hardness was measured to investigate the mechanical property of the complex. Cytocompatiblility was tested with human gingival fibroblast to all complexes using sodium chitosan phosphate as control. It was found that the complex with various mole ratios was feasibly formed by donating lone pair electrons from nitrogen of amine groups, oxygen of phosphate groups and oxygen of hydroxyl groups of sodium chitosan phosphate to water molecules surrounding on the surface of zinc oxide. All complexes with various mole ratios exhibited the metal complex degradation stage in the range of 200-220 °C that did not found in sodium chitosan phosphate. Hardness of the complexes increased as increasing the amount of zinc oxide. For direct contact test, the complexes with sodium chitosan phosphate to zinc oxide ratios of 1:0.25 and 1:0.5 showed biocompatibility as well as the control that was suitable for applying as periodontal dressing whereas, the complexes with mole ratios of 1:1 and 1:2 exhibited cytotoxicity due to large amount of zinc oxide covering the surface of complexes. For indirect contact test, the extracted solutions from all complexes with various mole ratios showed biocompatibility as well as the control.