Improved cytocompatibility and degradation control of iron by electroformed carvacrol film

FAGALI NS; FERNÁNDEZ LORENZO MA

Alicante

Congreso; 13th Symposium on Biodegradable Metals for Biomedical Applications; 2021

Biodegradable metals

INTRODUCTION: Iron (Fe) and some of its alloys have been proposed for degradable implants (stents, bone scaffolds, etc) [1]. However, in vivo and in vitro studies reported accumulation of voluminous insoluble degradation products [2]. This enhances the risk of breakage of the blood vessels. The goal of this work is to develop a strategy to control the degradation rate of pure Fe with an electroformed film of carvacrol. This natural compound is the main component oforegano essential oil.METHODS: The electroformed carvacrol-films were synthetized on pure Fe wires bypotentiodynamic cyclic voltammetry (CV) and potentiostatic chronoamperometry (CA) (70:30 water/ethanol solution, NaOH 0.03 M, carvacrol 0.1 M). To evaluate the corrosion inhibitory efficiency of the films, potential scanning in anodic direction was made in phosphate buffered saline (PBS) solution. The degradation rate was determined after immersions in PBS for 1, 2, 5 and 7 days by spectrocolorimetric technique. Cytotoxicity of the formed films was evaluated onfibroblasts BALB/c 3T3 cultures by Acridine Orange (AO) staining and epifluorescence microscopy.RESULTS:In the case of CA, three potential values were assayed and carvacrol films with different corrosion inhibition efficiency were obtained. This allows to select the best degradation rate for the implant site.The quantification of the released Fe-containing species, from bare Fe and carvacrol-coated Fe, revealed that films obtained by CV and CA were able to regulate the corrosion rate and consequently the accumulation of corrosion products.AO assays showed that Fe coated with carvacrol films, formed by both CV and CA, present higher viability of cells near the metal than the bare Fe.DISCUSSION & CONCLUSIONS: Formation of carvacrol films by electrochemical methods on Fe is a suitable strategy to regulate its degradation rate in order to fulfil the medical purposes, controlling the amount and the solubility of corrosion products. Moreover, those films improve the cytocompatibility of bare Fe.