On the biocompatibility of a novel Ti-based amorphous composite: structural characterization and in-vitro osteoblasts response.

Titanium and its alloys are frequently used as dental and orthopaedic implants due to their high mechanical strength, low elastic modulus and biocompatibility. However, as these materials have a poor wear resistance, tribo-chemical reactions during use produce debris accumulation, resulting in adverse cellular responses. In that sense, amorphous based materials are potential candidates, considering their hardness and crack growth resistance. This paper reports on the structural characterization of the as-quenched Ti45Zr38Ni17 alloy. This system displays a duplex structure never mentioned before with a low dispersion of nanometric beta-phase particles in an amorphous matrix. Moreover, in order to explore the biocompatibility of such composite, primary osteoblasts cultures are used to analyse cell behaviour around and upon the metallic surface. Osteoblasts attach and proliferate on the material as demonstrated by scanning electron microscopy. Cell proliferation and bone nodule formation are also observed in cultures with Ti45Zr38Ni17 particles by phase contrast microscope. In addition, transmission electron microscopy reveals ultrastructural features very close to those observed in vivo during intramembranous ossification with active osteoblasts surrounded by an extracellular matrix and a mineralized one. In conclusion, these results demonstrate that osteoblasts, cultured in presence of Ti45Zr38Ni17 alloy, proliferate, differentiate and synthesize bone matrix.