Biodegradable molybdenum as an implant material

Biodegradable metals have entered the implant market in recent years. Nevertheless, the properties of the materials used are not yet fully satisfactory. This paper presents molybdenum, which has particularly favourable properties for use in cardiovascular and orthopaedic implants, as a new material in medical technology. The degradation behaviour of commercially available sintered and hot-formed molybdenum sheet metal is investigated in vitro by measurements of ion concentration in the solution and REM/EDX analysis. It is shown that molybdenum gradually dissolves in simulated physiological fluid. A non-passivating and uniform layer of slowly soluble corrosion products forms at the exposed surfaces and gradually increases in thickness. Testing of molybdenum ion extract against human endothelial cells reveals no adverse effects on cell viability at concentrations expected for the dissolution of implants. The results indicate that thin structures made of pure molybdenum are well-suited for implant applications.