Enhancement of Corrosion Resistance of Phytic Acid Conversion Coating on Bioresorbable Magnesium Alloys Using PLGA

Abstract

In recent years magnesium alloys have been considered as novel bioresorbable materials Magnesium alloys possess good biocompatibility lightweight property mechanical properties similar to natural bones and bioresorbability making them become new alternatives over conventional titanium alloys and polymeric materials as orthopedic implants materials The drawback of magnesium alloys is the poor corrosion resistance leading to high degradation rate in human bodies Hence surface modification is needed to enhance their corrosion resistance In this study chemical conversion treatment with phytic acid (PA) was used to deposit a protective coating on high purity magnesium (HP-Mg) In order to seal the micro cracks appearing on the coating PLGA was used to manufacture a PA/PLGA composite coating The SEM photos and EDS analysis showed that PLGA successfully sealed the micro cracks on the PA conversion coating giving it a smooth surface The hydrogen evolution test pH variation test and polarization curves confirmed that the corrosion resistance was further enhanced after cracks were sealed with PLGA Cytotoxicity cell adhesion and wound healing assay indicated that PA/PLGA composite coating was biocompatible and did not pose bad effects on bone cells Besides the cell-implant interface phenomenon was explained by surface roughness and surface hydrophilicity Therefore from the results above the PA/PLGA composite coating manufactured in this study is a suitable candidate for the protection of magnesium implant materials and is not toxic to human bodies with a therapeutic property

Date of Award	2019
Original language	English
Supervisor	Ming-Long Yeh (Supervisor)