Date of Award

2015

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemical Engineering

First Advisor

Zhu, Donghui

Abstract

Biomaterials including ceramic material, polymer material, metallic material and composite material have been used in biomedical scaffolds, artificial tissues, and drug delivery systems for a long time. Magnesium (Mg) and Mg-based alloys are a new generation of degradable metallic materials that have attracted great attention in the last ten years. The advantages of Mg alloys as biomaterials are their good biocompatibility and biodegradability. Mg as an essential element in human body is an enzyme cofactor for over 300 biochemical reactions. However, the degradation process of Mg material may hinder the potential application. The purpose of this study is to evaluate the biocompatibility of pure Mg and Mg alloys by different in vitro methods. We believe that Mg material could be used as vascular stent material and bone orthopedic implant materials. The effect of different metals used in Mg stent materials on endothelial cells, biocompatibility of Mg-Rare Earth (RE) alloys, collagen self-assembly on Mg bone orthopedic material, and endothelialization on hydrofluoric acid conversion coating were studied. Scanning electron microscope, electrochemical corrosion test, hemolysis test, platelet adhesion test, cell viability test, cell proliferation test, immunostaining and q-PCR were used. Major results include: (i) the effect of Mg on endothelial cell viability and proliferation is dose-dependent; (ii) alloying with rare earth elements could improve endothelial cell attachment and viability; (iii) the structure of collagen self-assembly on Mg material is affected by collagen monomer concentration, assembly time, pH, and degradation products; and (iv) hydrofluoric acid conversion coating can improve endothelial cell attachment and proliferation. This study successfully shows that Mg alloys have the potential to be medical implant materials.

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