In Vitro Cytocompatibility Study of a Medical β-Type Ti-35.5Nb-5.7Ta Titanium Alloy

This research was part of a European Commission funded research project for the development of a new generation of titanium based orthopaedic biomaterials. In particular, hip implants of a beta-type Ti-35.5Nb-5.7Ta alloy were fabricated by the powder metallurgy route. An advanced surface treatment technology of Laser Engineered Net Shaping (LENS) was used to apply a ZrO2/Zr coating on the implant surfaces where relative movement takes place between the implant and the bone, in order to enhance the wear resistance. The present work was conducted to evaluate the cytotoxicity of the uncoated and ZrO2/Zr coated beta-type Ti-35.5Nb-5.7Ta alloy in both indirect and direct contact of human embryonic kidney 293T (HEK293T) cells. The cellular response was quantified by cell viability assessments using Alamar Blue assay and cell attachment. Cytotoxicity experiments showed that the responses of the uncoated and ZrO2/Zr coated alloy on surviving cells were nontoxic. HEK293T cells displayed appropriate survival rates, good cell adhesion and cell spreading. These results confirm that the beta-type Ti-35.5Nb-5.7Ta alloy, in both coated and uncoated conditions possesses good cytocompatibility, which allowed adhesion and proliferation of HEK293T cells to occur in both indirect and direct contact cell culture methods by Alamar Blue assay.