Microalloy Mg-based degradation implant for intra-osteal fixation

Abstract

The bottleneck for Mg-based degradable implants lies in the mismatching relationship between mechanical properties and degradable rate, resulting in the rapid failure during the in-vivo degradable process and potential toxic role. Herein microalloy-conception has been involved to rectify the equilibrium effects among several aspects. Microstructure, mechanical properties, degradable properties and in-vitro/in-vivo biocompatibility properties of as-extruded pure Mg, Mg-0.15Ca, and Mg-0.15Ca-0.10Mn samples have been investigated. The results show that the Mg-0.15Ca-0.1Mn alloy exhibits a high yield strength (110 MPa) and a low degradable rate (0.82 mm/y). Attractively, the mechanical integrity has been remained in Mg-0.15Ca-0.1Mn alloy after 14 weeks in the rat femoral mode, and a homogenous degradable rate with 0.92 mm/y has been confirmed, which are far lower than those in-vitro values. Simultaneously, the low concentration of ions also reveals satisfactory biocompatibility equal to pure Mg, based on organ function and pathological morphology. Our findings reveal that microalloy paves a possible route to design high performance Mg-based intra-osteal fixation implants, resolving the contradictions among the degradable requirements under different body environments.