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Imani, Amin

University of British Columbia

This thesis investigates the degradation behavior of a Mg-based alloy in the presence of organic constituents, specifically albumin and glucose, and explores their impact on the corrosion rate, biodegradation mechanisms, and surface potential changes. By contributing to understanding the complex interactions between Mg alloys and organic constituents, this research informs the development of safer and more effective biomedical implants. After an introduction, literature review, and methodology in Chapters 1 and 2, respectively, Chapter 3 compares the corrosion behaviour of CP-Mg in a NaCl environment using bovine serum albumin (BSA) and chicken egg albumin (CEA) as inhibitors. CEA provides superior corrosion protection, emphasizing the importance of accurately describing the albumin source and concentration in Mg biodegradation studies. Chapter 4 examines the chemical degradation of Mg alloy WE43 in modified simulated body fluids, revealing that glucose and BSA influence the corrosion rate and formation of corrosion products. Higher glucose concentrations reverse the inhibitory effect of BSA by competitively displacing BSA from binding sites, thereby mitigating its inhibitory impact. Chapter 5 focuses on the electrical surface potential of the protein nano-biofilm on WE43, showing that different simulated body fluids affect protein adsorption, conformation, and the alloy's surface potential, which is crucial for elucidating the alloy's biocompatibility and corrosion resistance in biomedical settings. Chapter 6 investigates stress corrosion cracking (SCC) in WE43 immersed in modified simulated body fluid (m-SBF), finding that organic constituents reduce the corrosion rate, with BSA forming a protective layer. Intergranular and transgranular cracking modes are observed in SCC propagation. These findings highlight the need to consider organic constituents in Mg-based implant design in order to accurately predict time-dependent degradation and optimize biocompatibility.

Text

2024-07-04

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/88571

Materials Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/