Date of Award
5-2024
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Bioengineering
Committee Chair/Advisor
Dr. Jeremy L. Gilbert
Committee Member
Dr. John DesJardins
Committee Member
Dr. Melinda K. Harman
Committee Member
Dr. Jeremy Mercuri
Abstract
The Essure device is a non-hormonal, minimally-invasive, permanent female sterilization implant, removed from the market due to an increase in adverse events, hypothesized to be caused by corrosion of the Sn-Ag component of the implant. The goals of this dissertation were to first develop implant retrieval methods for Essure devices and surrounding tissue, documenting signs of degradation and metallic degradation products, then to characterize the electrochemical behavior of Sn-Ag in biologically representative environments and finally, to assess the biological interaction of Sn-Ag. Retrieval analyses developed successful methods, qualifying the degree of corrosion, primarily of the Sn-Ag component and finding Sn ions to be high in the surrounding tissue. Electrochemical behavior of Sn-Ag appears to be electrode potential and solution dependent where, in simple solutions, at low temperatures, Sn-Ag behaves passively through -250 mV vs Ag/AgCl, then transitions into a transpassive/active behavior, undergoing pitting corrosion. When the solution becomes complex, temperature is increased, Sn-Ag is galvanically coupled to passive metals or organic coatings are applied, the passive behavior disappears and the outer corrosion layer begins to change in composition, from primarily oxygen and chloride, to include phosphorus. Lastly, in the passive region, cells are able to adhere and spread out on the surface, but as potentials rise they undergo cell death, though this behavior is experienced by this cell type on commonly used metallic biomaterials (e.g., CoCrMo) as well. When these cells are cultured in media conditioned with increasing amounts of SnCl2, cells experience a lethal dose around 0.5 mM, deeming SnCl2 to have mild toxicity effects also similar to other commonly used metallic biomaterial corrosion products. From these collective results, we conclude that Sn-Ag may act as a novel, potential controlled degradable metallic biomaterial.
Recommended Citation
Goodwin, Charley, "Tin-Silver as a Novel Biodegradable Metallic Biomaterial" (2024). All Dissertations. 3641.
https://tigerprints.clemson.edu/all_dissertations/3641
Author ORCID Identifier
https://orcid.org/0000-0002-3476-1153