A New Method for the Synthesis of Coatings of HA-Gelatin on Titanium

The paper discusses an alternative method - the synthesis of biomimetic composite coatings on a titanium alloy. With this method of obtaining materials, the bond of the implant with the bone develops due to the biomimetic formation of an active layer of hydroxyapatite on the surface of the titanium alloy. This layer is formed as a result of the transition of calcium ions from the implant material into the intercellular fluid, the composition of which is similar, for example, to the composition of the simulated human body fluid. In this study, we tried to synthesize a biomimetic composite based on a gelatin-calcium-phosphate coating on a titanium alloy VT1-0 and determine its structure, composition, and physicochemical properties. Synthesis of composite coatings on titanium alloy implants consisting of hydroxyapatite powder and 1%, 2% and 3% gelatin was conducted. The samples of titanium implants were immersed in the hydroxyapatite suspension with the addition of gelatin, while the pH value was 7.4, which corresponds to physiological. In the study, a titanium alloy of the VT1-0 grade was used, and its surface was preliminarily subjected to processing: it was polished, etched, and exposed to a powerful ion beam. The XRD data showed that samples synthesized in simulated body solution at different concentrations of gelatin are single-phase and represent hydroxyapatite. It has been established that the crystallization rate depends on the method of pretreatment of the titanium implant surface. A faster growth of crystals was observed on thin sections of polished specimens, while on etched specimens, dendritic growth occurred in bulk defects caused by etching. The consolidation of the composite layer was observed after exposure to a powerful ion beam.