Tuning the compositional configuration of hydroxyapatite modified with vanadium ions including thermal stability and antibacterial properties

Abstract

Different contributions of vanadate ions have been incorporated into hydroxyapatite (HAP) lattice with different concentrations using the co-precipitation technique. Vanadate ions have introduced a structural change of the HAP formula to be as: [Ca10(PO4)6-x(VO4)x(OH)2]; whereas 0.0≤x≤1.2. Vanadate dopants have a considerable effect on lattice parameters, whereas the a-axis starts from 9.483 Å and expands to its maxima of 9.602 Å. However, the c-axis begins with 6.916 Å and plunges to 6.853 Å for x = 0.0 and 0.6, respectively. Moreover, the compositions showed higher thermal stability till x = 1.0; then, it declined sharply. The thermodynamic parameters accompanied by the thermal degradation process have been calculated using Coats–Redfern and Horowitz–Metzger methods. Both dehydration and decomposition kinetics show endothermic, non-spontaneous, and slow decomposition reactions. The cell viability was enhanced for V-HAP and reached its highest value of 99.4 %. The highest vanadate concentration, the more effective as antibacterial material, whose inhibition zone reaches its maximum values of 20.4 ± 1.5 and 19.5 ± 1.3 mm against E. coli and S. aureus respectively. Subsequently, these types of biomaterials could be suggested for potential clinical applications.