Enhancing biointerfacial properties of porous pure iron by gold sputtering for degradable implant applications

Abstract

The inherent issue with the use of conventional metallic implants for temporary applications have brought attention on materials for degradable metallic implants. Such materials help in combining the superior performance of metals and eschewing a second surgery for the removal of temporary implants. Iron is considered as a promising candidate for developing biodegradable metallic implants due to its biocompatibility and biodegradability. However, it degrades slowly in the physiological environment, thus the metal needs to be improved for such applications. This work investigates the combined effect of gold sputtering and porous microstructure on degradation of iron in physiological environment. The effect of porosity and gold sputtering on bioactivity and cytocompatibility are also studied using simulated body fluid and cell culture respectively. Electrochemical tests reveal that the processed sample degrades nearly three times faster than untreated pure iron. Cytotoxicity studies performed on MG-63 osteoblast-like cells demonstrates that gold-sputtered samples exhibit improved cell viability, adhesion, and proliferation compared to untreated samples. The morphological and surface modification attempted increased the degradation rate and bioactivity of iron in the physiological environment. As the improvement in degradation rate needs the presence of gold ions, the process is proposed for developing temporary metallic implants with thin sections.