← Back to Search
Surface Modification By Natural Biopolymer Coatings On Magnesium Alloys For Biomedical Applications
Published 2015 · Materials Science
Abstract Natural biopolymers possess good biocompatibility and exhibit excellent bioactivity due to the components of the extracellular cell matrix, which are abundant in the biomass and are easily accessible from a range of sources, such as forest products, grasses, tunicates, crustacean, and stalks. In this chapter, magnesium alloys modified with a natural biopolymer coating to improve their biocompatibility and degradation properties are introduced. Some natural biopolymers, such as chitosan, phytic acid, collagen, and stearic acid have been studied and coated on the surface of magnesium alloy for biomedical applications. Enhanced corrosion resistance, improved biocompatibility, and a reduced hemolysis ratio of WE43 was achieved after modification with phytic acid solution with different pH values of the conversion coating, especially when the pH value of the modified solution was 5. Various chitosan dip-coated Mg-1Ca alloys also displayed greater corrosion resistance in simulated body fluid. Calcium phosphate/chitosan composite films coated on the surface of micro-arc oxidized (MAO)-AZ91D alloy through electrophoretic deposition or on the surface of AZ31 alloy by aerosol deposition were adopted to enhance the bond strength between the magnesium substrate and hydroxyapatite. Stearic acid coating on hydrothermal-treated Mg samples enhanced the corrosion resistance of Mg. A drug release system on MAO-WE42 was established by a cross-linked gelatin/PLGA particle loaded with paclitaxel. Finally, a comparatively smooth surface of magnesium coated with albumin attached via linker groups was employed for better corrosion property, taking advantage of the presence of an Mg(OH)2-terminated MgO layer via silane coupling chemistry. Although the data and literature are limited in this area, previous works have validated the effectiveness and function of natural polymers on the corrosion resistance and biocompatibility of magnesium alloys, and much more research is expected in the future.