Evaluation of in vitro corrosion resistance and in vivo osseointegration properties of a FeMnSiCa alloy as potential degradable implant biomaterial
Fecha
2020Resumen
In vitro electrochemical characterization and in vivo implantation in an animal
model were employed to evaluate the degradation behavior and the biological activity of
FeMnSi and FeMnSiCa alloys obtained using UltraCast (Ar atmosphere) melting.
Electrochemical characterization was based on open circuit potential measurement,
electrochemical impedance spectroscopy and potentiodynamic polarization techniques
while the alloys were immersed in Ringer’s solution at 37 ºC for 7 days. Higher corrosion
rates were measured for the Ca-containing material, resulting from inefficient passivation
of the metal surface by oxy-hydroxide products. In vivo osseointegration was investigated
on a tibia implant model in rabbits by referring to a standard control (AISI 316L) stainless
steel using standard biochemical, histological and radiological methods of investigation.
Changes in the biochemical parameters were related to the main stages of the bone fracture
repair, whereas implantation of the alloys in rabbit’s tibia provided the necessary
mechanical support to the injured bone area and facilitated the growth of the newly
connective tissue, as well as osteoid formation and mineralization, as revealed by computed
tomography reconstructed images and validated by the bone morphometric indices. The
present study highlighted that the FeMnSiCa alloy promotes better osteoinduction and
osseointegration processes when compared to the base FeMnSi alloy or with AISI 316L,
and in vivo degradation rates correlate well with corrosion resistance measurements in
Ringer’s solution.