Rare transition metal doped hydroxyapatite coating prepared via microwave irradiation improved corrosion resistance, biocompatibility and anti-biofilm property of titanium alloy

Abstract

Here, we synthesized niobium doped hydroxyapatite (Nb-HAP) coatings on grade-5 titanium (Ti6Al4V) alloy sheets via microwave irradiation for the improvement of its biocompatibility and corrosion resistance with excellent antibiofilm function. The functionalized coated sample confirmed the presence of calcium deficient hydroxyapatite (HAP) containing niobium (Nb). The coating was observed to be denser, thicker and crystalline after doping. The average roughness of the surface was enhanced and became more hydrophilic with the functionalization of Nb. Moreover, the doping was found to have greatly improved the corrosion resistance of the substrates. The apatite layer on the Ti alloy surface revealed to adsorb more protein and enhanced the cell survival by more than 30 %. The presence of Nb in the coating ensured anti-biofilm property against both gram -ve and gram +ve bacteria strains. An improved hemocompatibility towards goat erythrocytes and cytocompatibility towards human keratinocyte cells were also evident in the post coating state. Hence, the microwave-assisted preparation of Nb doped HAP coating not only could improve the physical traits of the substrate, but could enhance the biocompatibility of bone implant as well. Furthermore, the microwave irradiation techniques used here might make the process faster and economical for efficient bioactive HAP coating deposition on Ti alloy. • Microwave assisted niobium doped HAP coating was deposited on Ti alloy sheet. • The doping improved crystallinity and hydrophilicity of the coated surface. • Reinforcement of niobium improved the corrosion resistance of the metal alloy. • The coatings were noncytotoxic, hemocompatible and resistant to bacterial growth.