Biodegradable implants show great potential in many areas of medicine, and have already demonstrated success in simple applications such as sutures. For more complex devices, such as vascular stents, there are considerable challenges associated with the use of biodegradable materials. These materials typically are weaker than the metals currently used to construct stents, so it is difficult to ensure sufficient strength to prop open the artery and alleviate symptoms acutely. It is even more challenging to design a stent that provides structural support for a predictable, appropriate time to facilitate artery healing. These challenges are evident when one considers that there are no biodegradable stents on the US market despite more than 20 years of development efforts. This review summarizes previous efforts at implementing biodegradable stents, discusses the specific challenges involved, and presents a recently developed biodegradable material modeling framework that can benefit this exciting field.
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A note on terminology: Biodegradable polymers are polymers that are decomposed in the body, but whose degradation products remain in tissues. On the other hand, bioresorbable polymers can be defined as polymers that degrade after implantation into nontoxic products, which are then eliminated from the body or metabolized. Although this last term is more precise, it is often used interchangeably with absorbable, resorbable, bioabsorbable, and biodegradable.26 For the purposes of this document, “biodegradable” will encompass all of these terms.
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The authors gratefully acknowledge support from the National Institutes of Health (R01 EB000115 to JEM), the Portuguese Fundação para a Ciência e Tecnologia (SFRH/BD/17060/2004 and SFRH/BPD/63119/2009 to JSS), and the National Science Foundation (to KRR).
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Moore, J.E., Soares, J.S. & Rajagopal, K.R. Biodegradable Stents: Biomechanical Modeling Challenges and Opportunities. Cardiovasc Eng Tech 1, 52–65 (2010). https://doi.org/10.1007/s13239-010-0005-7
- Corrodible metals
- Mechanical properties