Evaluation of the TiMo12Zr6Fe2 alloy for orthopaedic implants: in vitro biocompatibility study by using primary human fibroblasts and osteoblasts

To reveal the biocompatibility of TiMo12Zr6Fe2 (TMZF), a new titanium alloy used since 1998 for orthopaedic prosthesis, we compared the behavior of primary human fibroblasts and osteoblasts grown on TMZF discs or on plastic tissue culture dishes, a widely used material specifically treated by the manufacturer to enhance cell growth. Proliferation, differentiation, RNA and collagen type I expression level of human cells were carried out. The analysis were performed over a period of 96 h. Fibroblasts behaved at the same way on the two different supports after 48 h, their number increased after 96 h when cells were grown on the alloy. Osteoblasts adhered and proliferated on the alloy discs as well as on plastic. RNA expression level was not affected. Interestingly, cell number at each time point was higher for fibroblasts than for osteoblasts. The RNA expression level was higher for the osteoblasts. Both cell types cultured on the alloy revealed an increase in the amount of type I collagen and a similar electrophoretic pattern was found for collagen produced by fibroblasts and osteoblasts grown on either supports. These results indicate good biocompatibility of the TMZF alloy, which allowed adhesion and proliferation of both the examined cell types and suggest that TMZF is a promising material for orthopaedic implants.