Controlling the degradation rate of gelatin- modified AZ91 magnesium alloy in means of dip/spin-coating procedures

摘要

Presently, magnesium and magnesium alloys are largely being investigated as the innovative bio-degradable implant material owing to their excellent biocompatibility. The temporary implants are destined to corrode and dissolve completely, hence eliminating the need of second surgery for the removal of implant. But sometimes the higher degradation rates hinder with the healing process and need for controlled degradation arises. Many methods have been developed over the decades to combat this issue, like alloying, micro arc-oxidation method and coatings. The objective of this study is to investigate the corrosion behavior of AZ91 magnesium alloy coated with gelatin biopolymer. In that respect, two different coating approaches will be applied: the dip coating and spin coating, both providing in situ chemical (e.g. carbodiimide -mediated) stabilization of gelatin. Simulated body fluid (SBF) incubation will be performed in order to evaluate time/coating process-related improvement of the Mg alloy deterioration rate and its kinetic profile, for what weight loss will be calculated in parallel with Capillary Electrophoresis (CE) evaluation of released Mg ions Moreover, the corrosion studies will be carried out using potentiodynamic polarization technique and the electrochemical impedance measurements in SBF solution at different time points. All samples will be imaged in means of SEM, before and after SBF incubation in order to generate an visual picture for surface structure of non/treated Mg allow before and after gelatin coating.