Properties of Coatings Based on Calcium Phosphate and Their Effect on Cytocompatibility and Bioactivity of Titanium Nickelide

Abstract

Coatings based on calcium phosphate with thicknesses of 0.5 and 2 μm were obtained by high-frequency magnetron sputtering on NiTi substrates in an argon atmosphere. The coating was characterized using X-ray diffraction, scanning electron microscopy, atomic force microscopy, and in vitro cytocompatibility and bioactivity studies. A biphasic coating of tricalcium phosphate (Ca3(PO4)2) and hydroxyapatite (Ca10(PO4)6(OH)2) with a 100% degree of crystallinity was formed on the surface. The layer enriched in calcium, phosphorus, and oxygen was observed using scanning electron microscopy and energy-dispersive X-ray spectroscopy. Scanning electron microscopy showed that the surface structure is homogeneous without visible defects. The 2 µm thick coating obtained by sputtering with a deposition time of 4 h and a deposition rate of 0.43 µm/h is uniform, contains the highest amount of the calcium phosphate phase, and is most suitable for the faster growth of cells and accelerated formation of apatite layers. Samples with calcium phosphate coatings do not cause hemolysis and have a low cytotoxicity index. The results of immersion in a solution simulating body fluid show that NiTi with the biphasic coating promotes apatite growth, which is beneficial for biological activity.

Influence of casein phosphopeptide-amorphous calcium phosphate on the surface topography and composition of nickel-titanium archwires during orthodontic treatment with fixed appliances

“…A biofilm, enriched with precipitated Ca and P as a result of exposure to CPP-ACP, might act as a protective layer and reduce the surface Ni content of orthodontic wire. The ongoing development of novel calcium phosphate coatings for NiTi alloys aimed at biomedical application [38][39][40] underscores the potentially protective and anticorrosive nature of CPP-ACP. The use of CPP-ACP holds promise for application as a safe anticariogenic alternative to fluoride in orthodontic patients, acting as a chemoprophylactic agent with anticorrosion properties.…”

Enhanced Biocompatibility and Osteogenic Property of Biodegradable Zn-0.5Li Alloy through Calcium–Phosphorus Coating

“…It was reported that a Zn-1.5 Mg alloy was treated in a supersaturated calcium-phosphorus solution at 37 • C for 14 days, which resulted in the formation of a protective layer of calcium-rich phosphate on the alloy surface, and that cell viability and adhesion were significantly enhanced when U-2 OS cells were cultured on the calcium phosphate-protected film [16]. In another study, CaP coatings were prepared by high-frequency magnetron sputtering, and it was found that bone marrow mesenchymal stem cells (MSCs) adhered well to the coating surface and showed good proliferation [24]. In an in vivo study of CaP coatings prepared on zinc alloy surfaces, no significant inflammatory or adverse reactions were observed around the implants.…”