Regulating Degradation Behavior by Incorporating Mesoporous Silica for Mg Bone Implants

Magnesium (Mg) alloys are potential bone implant materials because of their natural biodegradability, good biocompatibility and suitable mechanical properties. However, the too rapid degradation in physiological environment has delayed their introduction for orthopedic applications to date. To improve the degradation behavior, mesoporous silica (MS) was incorporated into ZK60 (Mg-6Zn-0.5Zr, wt %) via selective laser melting technology. Results showed that MS homogeneously incorporated in Mg matrix with good bonding interface. MS was chemical inert against Mg and shifted the corrosion potential positively, indicating an enhanced corrosion resistance. Moreover, MS promoted the deposition of apatite on surface and formed a compact protection layer, thus effectively preventing the further corrosion of Mg matrix. As a result, the degradation rate was reduced by 57%, with MS containing up to 8 wt %. In addition, ZK60/8MS composite exhibited improved biocompatibility. It was suggested the ZK60/8MS composite with improved degradation behavior and good biocompatibility was a potential candidate biomaterial for the bone implants.