Enhanced Biocompatibility and Antibacterial Activity of Selective Laser Melting Titanium with Zinc-Doped Micro-Nano Topography

Abstract

Selective laser melting (SLM) titanium is a suitable material for use in customized implants. However, long-term implant survival requires both successful osseointegration and promising antibacterial characteristics. Native SLM titanium thus requires proper modifications to improve its bioactivity and antibacterial efficacy. Micro-arc oxidation (MAO) was conducted on sandblasted SLM substrate to form a microporous TiO2 coating. Subsequently, hydrothermal treatment was applied to fabricate micro-nano zinc-incorporated coatings with different Zn content (1 mM-Zn and 100 μM-Zn). Surface characterization was performed using scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, a three-dimensional profilometer, and a contact angle measuring device. The osteoblast-like cell line MC3T3-E1, Subclone 14, was used in cell viability assays to evaluate adhesion, proliferation, and ALP activity. An antibacterial assay was conducted using Streptococcus sanguinis and Fusobacterium nucleatum. Zn-incorporated samples exhibited higher adhesion, proliferation, and differentiation than did SLM and MAO samples. 100 μM Zn samples exhibited the highest proliferation, and 1 mM-Zn samples manifested the highest ALP activity. In addition, Zn-incorporated samples exerted inhibitory effects on both Streptococcus sanguinis and Fusobacterium nucleatum. Combining micro-arc oxidation and hydrothermal treatment, we successfully fabricated a novel Zn-incorporated coating on a microporous SLM surface which possesses both outstanding bioactivity and antibacterial efficacy.

Influence of Successive Chemical and Thermochemical Treatments on Surface Features of Ti6Al4V Samples Manufactured by SLM

“…As an example, the SEM images of the Ti6Al4V sample before and after the acid etching at 80 • C for 20 min are displayed in Figure 2. The as-prepared SLM samples showed surface morphological features according to those reported in previous studies (Figure 2a) [25,36]. Residual partially melted powder particles (protrusions) were found on the surface of the native SLM samples that showed a rough wavy surface without nano-topographic characteristics.…”

Surface Properties and Biocompatibility of Anodized Titanium with a Potential Pretreatment for Biomedical Applications

“…Accordingly, the rising effective surface area that will increase the hydrophilicity of the surface [1,26]. Good wettability will have an impact on the absorption of biological fluids, proteins, and cells on the Ti surface, as well as affecting cell morphology, adhesions, and proliferation [21,29,30].…”

Surface Modification of Titanium Implants by Metal Ions and Nanoparticles for Biomedical Application

“…The layer had strong hydrophilicity, surface roughness, balanced biological activity, and antibacterial effect. 148 (3) The surface morphology of nanocoating can form a unique microenvironment, promote osteoblast differentiation, and regulate the behavior of osteoblast-related cells. 145 The unity and surface morphology of ZnO-NPs should be studied due to their specific toxicity to improve osteoblast activity.…”