Medical Physics and Biophysics

It is well known that appropriate level of reactive oxygen species (ROS) can promote angiogenesis in biological systems. Although the application of ROS has been extensively studied in vitro and in vivo to stimulate the new vessel formation, those systems employ external stimuli such as light or electrical energy to produce ROS via photocatalytic or electrochemical reactions, which limits their clinical applications. Here, two different types of biocompatible metals were used to construct a novel device-free electrochemical system that can spontaneously generate H2O2 without any external light or electric current. The corrosion of Mg generates electrons which can be transferred to oxidized Ti in an energetically favorable process, and consumed for the generation of H2O2 in an oxygen reduction reaction (ORR). Combined spectroscopic and electrochemical analyses revealed the occurrence of ORR at the surface of titanium, the main materials of the conventional medical implants. The controlled generation of H2O2 noticeably enhanced in vitro angiogenesis even in the absence of growth factors. A prototype titanium-magnesium implant was suggested, and its potential for promoting in vitro angiogenesis was demonstrated.