title: A simplified in vivo approach for evaluating the bioabsorbable behavior of candidate stent materials.
abstract: Metal stents are commonly used to revascularize occluded arteries. A bioabsorbable metal stent that harmlessly erodes away over time may minimize the normal chronic risks associated with permanent implants. However, there is no simple, low-cost method of introducing candidate materials into the arterial environment. Here, we developed a novel experimental model where a biomaterial wire is implanted into a rat artery lumen (simulating bioabsorbable stent blood contact) or artery wall (simulating bioabsorbable stent matrix contact). We use this model to clarify the corrosion mechanism of iron (≥99.5 wt %), which is a candidate bioabsorbable stent material due to its biocompatibility and mechanical strength. We found that iron wire encapsulation within the arterial wall extracellular matrix resulted in substantial biocorrosion by 22 days, with a voluminous corrosion product retained within the vessel wall at 9 months. In contrast, the blood-contacting luminal implant experienced minimal biocorrosion at 9 months. The importance of arterial blood versus arterial wall contact for regulating biocorrosion was confirmed with magnesium wires. We found that magnesium was highly corroded when placed in the arterial wall but was not corroded when exposed to blood in the arterial lumen for 3 weeks. The results demonstrate the capability of the vascular implantation model to conduct rapid in vivo assessments of vascular biomaterial corrosion behavior and to predict long-term biocorrosion behavior from material analyses. The results also highlight the critical role of the arterial environment (blood vs. matrix contact) in directing the corrosion behavior of biodegradable metals.
authors: Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan 49931-1295, USA.
authors: Daniel
authors: D
authors: Pierson
authors: Jacob
authors: J
authors: Edick
authors: Aaron
authors: A
authors: Tauscher
authors: Ellen
authors: E
authors: Pokorney
authors: Patrick
authors: P
authors: Bowen
authors: Jesse
authors: J
authors: Gelbaugh
authors: Jon
authors: J
authors: Stinson
authors: Heather
authors: H
authors: Getty
authors: Chee Huei
authors: CH
authors: Lee
authors: Jaroslaw
authors: J
authors: Drelich
authors: Jeremy
authors: J
authors: Goldman
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D003343:Corrosion; D007501:Iron / Q000737:chemistry; D008274:Magnesium / Q000737:chemistry; D008422:Materials Testing / Q000379:methods*; D008954:Models, Biological; D051381:Rats; D017207:Rats, Sprague-Dawley; D015607:Stents; D013997:Time Factors
chemical_list: D007501:Iron; D008274:Magnesium