Boron-incorporated biocomposite coatings on 316L and NiTi alloys: Enhanced structural, antibacterial activity, and cell viability performances

Abstract

Boron doped (5 %, 10%, and 15 wt.%) Hydroxyapatite (B-HA) biocomposites were syntesized and coated on 316L SS and NiTi (Ni-45Ti) metallic substrates by using the electrophoretic deposition process (EPD). The morphological and structural characterization of the coatings was executed using scanning electron microscopy (SEM) and X-ray diffraction devices (XRD). Antibacterial tests were conducted using Escherichia coli (E. coli, JM103) and Staphylococcus aureus (S. aureus, ATCC29293) microorganisms. The mitochondrial activity assay (MTT)-[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] was used to examine cell viability and cytotoxicity in Saos-2 osteoblast cells. HA and boron peaks, as well as B-TCP and metallic components, were detected in XRD examinations. Porous morphologies were generated on the surface with boron doped B-HA coatings, as revealed by SEM views. Antibacterial activity studies revealed that both metallic coating groups, notably with boron doping, demonstrated antibacterial activity against gram-negative E. coli and gram-positive S. aureus. The antibacterial activity of the 316L group was shown to be better than that of the NiTi group in comparisonal testing. The syntesized boron-doped biocomposite coatings did not have any detrimental effects on living cells, according to cell viability studies. The cell viability rate was found to be greater in NiTi coatings than in 316 SS coatings, and the impact was amplified by the addition of boron.

Keywords: 316L; NiTi; antimicrobial activity; boron; cell viability; electrophoretic coating; hydroxyapatite.