Biocompatibility study of coatings obtained by atomic layer deposition on titanium implants made of various alloys

Restoration of bone tissue following trauma, congenital defects, or tumor resection remains one of the key challenges in medicine. Traditional autotransplantation methods are limited by donor material availability and the invasive nature of tissue harvesting. This has driven research into biocompatible materials that mimic bone tissue, particularly those based on titanium and its alloys. However, while pure titanium lacks sufficient mechanical strength, alloys (e.g., Ti6Al4V) may exhibit inferior biocompatibility due to aluminum and vanadium impurities. The aim of this study was to investigate the effects of nanoscale titanium dioxide (TiO2) coatings, deposited via atomic layer deposition (ALD), on the biocompatibility of titanium implants for maxillofacial surgery. Samples made of VT6 alloy (Grade5) were fabricated using selective laser sintering (SLS) and electron beam melting (EBM) techniques, followed by application of 25 nm TiO2 coatings. Elemental analysis revealed titanium oxidation (27.4% oxygen content) in SLS-produced samples, while EBM samples showed no oxidation. The TiO2 coating reduced surface concentrations of aluminum and vanadium, thereby enhancing biocompatibility. Testing with mesenchymal stem cells (MSCs) demonstrated that coated samples increased nucleic acid content in the secretome by 6—11% compared to control (Grade2 titanium) and by 22—27% compared to uncoated VT6 alloy. Conclusions. Additive manufacturing technologies (SLS and EBM) improve the biocompatibility of VT6 alloy (Grade5). 25 nm TiO2 coatings further enhance osseointegration properties. The ALD method effectively creates barrier layers that mitigate migration of harmful impurities.