Cytocompatibility by MTT assay and platelet adhesion of Ti and Ti-6Al-4V coated with hydroxyapatite in different plasma gas atmospheres

Aim: This study was performed to evaluate the biocompatibility of pure titanium and Ti-6Al-4V metals coated with hydroxyapatite (HA) by plasma spray using different plasma gas atmospheres. Materials and methods: The cell viabilities for each HA-coated sample in an atmosphere of argon, argon–hydrogen, nitrogen, and nitrogen–hydrogen were studied using MTT assay and platelet adhesion test. Results: The mean cell viabilities by MTT [3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide] assay of samples coated with HA in argon–hydrogen plasma atmosphere showed maximum cell viability at different time intervals compared with other coating atmospheres of argon–hydrogen, nitrogen, and nitrogen–hydrogen. A statistically significant value of cell viability (p < 0.001) was observed between and within the groups of argon, argon–hydrogen, nitrogen, and nitrogen–hydrogen plasma gas atmosphere. The platelet adhesion study showed agglomerates of platelet cells in some isolated regions of HA for all atmospheres. Significance: The results obtained in this study can serve as a guide for the development of new Ti-based HA-coated implants in different plasma gas atmospheres.