Rare earth oxides nanoparticles formed on the surface of WE43 magnesium alloy subjected to anodic oxidation plus heat treatment for anti-bone tumor

Abstract

It was well known that rare earth elements (REE) oxides nanoparticles could inhibit tumor growth and promote osteogenesis. In this works, four WE43 magnesium alloys (AO-10, AO-30, AO-1h and AO-2h) containing different REE oxides nanoparticles were prepared by anodic oxidation plus heat treatment. The REE oxides nanoparticles on AO-10, AO-30, AO-1h and AO-2h surface were Gd2O3 and Nd2O3, (Gd0.745Y1.255)O3 and Nd2O3, (Gd0.18Y1.82)O3 and Gd2O3 as well as Y2O3 and Gd2O3, respectively. Subsequently, the bioactivity, antitumor property and osteogenic property of all materials in vitro and in vivo were studied, and their antitumor property, bioactivity and osteogenic property were all AO-2h > AO-1h > AO-30 > AO-10. The degradation behaviors of materials in vitro and vivo were further investigated, and the corrosion resistance of materials was AO-10 > AO-30 > AO-1h > AO-2h. AO-2h released the most H2 and produced the highest pH value in all materials during degradation. The results showed that the effects of different REE oxides nanoparticles on corrosion resistance, biactivity, osteogenic property and antitumor property of materials were different completely. In all materials, AO-30 had moderate inhibition of MG63 and 143B cells in vitro, and it could inhibit the growth of bone tumor in mice in vivo. Then, the osteogenic property of AO-30 was moderate. It could promote the adhesion and proliferation of MC3T3-E1 cells. Again, the corrosion resistance of AO-30 was relatively excellent. It release few H2, Mg2+ and REE. The REE levels in normal tissues were relatively low, whose effects was negligible. Hence, AO-30 was the most suitable material for anti-bone tumor in all materials.