Electroformed pure iron as a new biomaterial for degradable stents: In vitro degradation and preliminary cell viability studies☆

In the search for a metallic material showing moderate and uniform degradation for application as degradable cardiovascular stents, electroformed iron (E-Fe) was evaluated by in vitro degradation and cell viability tests. Static immersion and dynamic degradation were used to evaluate degradation rate and mechanism, while cell viability assay was used to assess cytotoxicity. The results were compared with those of iron fabricated by casting and thermomechanical treatment previously investigated as a stent material. Electroformed iron showed faster degradation than iron fabricated by casting (0.25 vs. 0.14 mm year(-1)), with a uniform degradation mechanism. Cell viability results showed that E-Fe did not result in a decrease in metabolic activity when exposed to primary rat smooth muscle cells. However, it caused a decrease in cell proliferation activity which could be beneficial for the inhibition of in-stent restenosis.