Effect of samarium oxide nanoparticles on degradation and invitro biocompatibility of magnesium

Abstract

Benefitting from the advantages of being bioresorbable and having an elastic modulus, density and mechanical properties that closely match load-bearing bones, magnesium (Mg)-based materials are emerging as superior alternatives to permanent implants like titanium and stainless steel in orthopedic and craniofacial trauma fixation. To inhibit faster degradation of magnesium in physiological environments that has greatly limited its widespread clinical applicability, thermally stable metal-oxide nanoparticles have been used as a reinforcement to simultaneously improve the biomechanical and corrosion properties. Against this background, the objective of this study was to develop non-toxic magnesium-based nanocomposites incorporating rare earth oxides (REOs) synthesized by powder metallurgy technique followed by microwave sintering. The influence of rare-earth oxide (Sm2O3) nanoparticles on the microstructure, degradation, and biological performance of magnesium was investigated. The immersion test for 28 days revealed the rate of corrosion in Mg/1.5 vol.% Sm2O3 was 1.028 mm/year, reflecting a 25 % improvement compared to Mg. The viabilities of MC3T3-E1 cells for up to 1 vol.% Sm2O3 addition was >70 % indicating good in-vitro cytocompatibility while the lactate dehydrogenase (LDH) assay revealed all the nanocomposites exhibited Level ‘0’ cytotoxicity. The potential of rare-earth oxide reinforced magnesium nanocomposites, as explored in this work, was found to be suitable for temporary implant instead of rare-earth alloying addition to magnesium, which has known to cause potential toxicity.