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AsianScientist (Sep. 13, 2013) – Researchers from the United States and China have developed biodegradable magnesium alloy stents for the treatment of hardening arteries.
Atherosclerosis is a precursor to heart disease that occurs when artery walls thicken due to a build-up of cholesterol. It can be treated by surgically inserting a stent, which prevents blood-flow constriction. Most stents require further surgery to remove them.
The biodegradable metal alloys, published in Nanoscale, may emerge as a new class of biomaterials for tissue engineering and medical devices such as cardiovascular stents. Deploying biodegradable materials to fabricate stents not only obviates a second surgical intervention for implant removal but also circumvents the long-term foreign body effect of permanent implants.
However, although some biodegradable stents are already being used in clinical trials, their degradation is non-uniform and could cause structural damage. These materials for stents suffer from an un-controlled degradation rate, acute toxic responses, and rapid structural failure presumably due to a non-uniform, fast corrosion process.
In this study, the research team produced stents from a magnesium, zinc and zirconium alloy, called JBDM, that dissolved in a highly homogeneous nanophasic biodegradation pattern in vitro. Cytotoxicity tests in vitro using human vascular endothelial cells indicated excellent biocompatibility and potentially minimal toxic effect on arterial vessel walls.
Finally, the authors implanted the stent in an rabbit animal model for 16 weeks, and showed that the magnesium alloy biodegraded in a uniform manner and maintained their structure. They confirmed the stents’ reduced degradation rate in vivo, excellent tissue compatibility and long-term structural and mechanical durability.
The article can be found at: Mao L et al. (2013) Nanophasic biodegradation enhances the durability and biocompatibility of magnesium alloys for the next-generation vascular stents.
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Source: RSC.
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