posted on 2021-05-24, 16:34authored byGenwen Mao, Xinxin Jin, Juan Sun, Xuezhe Han, Min Zeng, Yusheng Qiu, Weiguo Bian
Mg
and its alloys have been comprehensively studied and show huge
potential for clinical orthopedic applications. However, balancing
the mechanical strength and corrosion resistance of alloys is still
a challenge. In light of this, micro-level contents of Zn and Ca were
added to pure Mg to fabricate a Mg–2Zn–0.05Ca microalloy
to expectedly enhance the mechanical strength and concurrently improve
the corrosion resistance. The characteristics of the rolled Mg–2Zn–0.05Ca
microalloy were explored using optical microscopy, X-ray diffraction,
and tensile tests. The corrosion behavior and mechanical strength
loss were explored using electrochemical and immersion tests. The
effects of the microalloy extract on the proliferation, adhesion,
and osteogenic differentiation of MC3T3-E1 cells were systematically
studied. Moreover, implantations were done in femoral condyles of
rabbits to study the degradation properties, osteogenic effect, mechanical
strength loss, and biosafety of the microalloy. The ultimate tensile
strength and yield strength of the rolled microalloy were found to
be significantly elevated to 257 ± 2.74 and 237.6 ± 8.29
MPa, respectively. The microalloy showed a stable and gradual strength
loss during degradation, both in vivo and in vitro. Concurrently, the microalloy exhibited improved
corrosion resistance ability and especially, in vivo, the rolled microalloy exhibited a comparable degradation rate to
that of rolled pure Mg within the initial 12 weeks of implantation.
Additionally, the microalloy promoted osteogenesis, both in
vitro and in vivo, and no short- and long-term
toxicities of the microalloy were observed in rabbits. This study
suggested that the rolled Mg–2Zn–0.05Ca microalloy effectively
balanced the mechanical strength and corrosion resistance and showed
potential application as bone implants.