Formation of hydroxyapatite coatings with addition of chitosan from aqueous solutions by thermal substrate method

Abstract

The aim of this investigation was obtaining of biocompatible coatings for medical implants based on biopolymer chitosan and hydroxyapatite, which is the main mineral component of bone tissue. Coatings were obtained by thermal substrate method, because it allows low temperature deposition and provides possibility to incorporate into coating structure biomolecules, unstable at high temperatures. As a way of chitosan incorporation into coating composition co-precipitation method was proposed. It allows obtaining uniform coatings with required composition and morphology. The obtained coatings were investigated by using of XRD, SEM with EDS, adhesion was tested by test-tape method. It was assigned that chitosan addition decreased hydroxyapatite crystallinity, so the range of concentrations from 0.01 to 0.1 g/L was chosen at pH = 6.5. It was determined that variation of chitosan concentrations in the initial solution influenced on morphology and structure of hydroxyapatite coatings as well as on the antibacterial properties and the use in orthopedics and dentistry. The best characteristics were obtained for hydroxyapatite-chitosan coatings deposited from solution with chitosan concentration 0.025 g/L.