Eradication of burst release of copper ions from copper-bearing IUDs by a phytocompound-based electropolymeric coating

Abstract

Copper bearing IUDs main disadvantage is the initial high release (burst release) of copper ions that causes an increased inflammatory response in surrounding tissues and several side effects. In this work, we studied the performance of Cu coated with an electropolymer obtained by potentiostatic polarization of a phytocompound, carvacrol, at 400 mV (SCE) (polyCarvCu-400 mV) in simulated intrauterine fluid (SUF) and its biocompatibility in a fibroblastic cell line. Corrosion studies with polyCarvCu-400 mV revealed a 107 ± 5 mV anodic shift of corrosion potential and an important decrease in corrosion current. PolyCarvCu-400 mV immersed in SUF for 3 and 15 days also evidenced a drastic reduction in the release of copper ions with respect to bare copper. Notwithstanding, concentrations of released copper (4.6–9.2 μg/day during the first 3 days and 2.0–4.00 μg/day during 15 days) are enough to guarantee the contraception action. PolyCarvCu-400 mV also showed a higher biocompatibility than bare Cu when fibroblast cell viability was assayed and, additionally, an enhanced cell growth on the metal surface than untreated copper. Results indicate that polyCarvCu-400 mV coating provides excellent improvements related to untreated Cu-bearing IUDs, avoiding the burst release side effects and enhancing the biocompatibility of the device.