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Mechanism, Anti-Corrosion Protection and Components of Anti-Corrosion Polymer Coatings
Published in Sanjay Mavinkere Rangappa, Jyotishkumar Parameswaranpillai, Suchart Siengchin, Polymer Coatings, 2020
Akarsh Verma, Naman Jain, Shweta Rastogi, Vaishally Dogra, Sanjay Mavinkere Sanjay, Suchart Siengchin, Rokbi Mansour
In 1994, bare metal stents were used to treat coronary artery disease, but they have major issue of stent thrombosis and restenosis [14]. Siroliums and paclitaxel drugs were used with the coating materials for first-generation drug-eluting stents made up of stainless steel [15,16]. Later, Bege et al. [15] reduced stent thrombosis by applying coating of poly(ethylene carbonate) (PEC) and paclitaxel with the help of spray coating. The amount of paclitaxel varies with the increase in coating layer, and within two days drug is released 100% via diffusion. Everolimus and zotarolimusin drugs were used with polymer coating in the second-generation drug-eluting stent.
Recent Advances in Biocompatibility
Published in Yaser Dahman, Biomaterials Science and Technology, 2019
Before 2003, bare metal stents were used to treat coronary artery diseases (Kim et al., 2012; Galløe et al., 2017). The main problem with bare metal stents is restenosis (Bedair et al., 2015). Restenosis is defined as a neo-intimal hyperplasia caused by smooth muscle cell migration, macrophage recruitment (inflammation), and extracellular matrix formation (thrombus reorganization) (Ma et al., 2011; Hamada et al., 2010). Restenosis can take up to several weeks to form and affects the implant’s biocompatibility success (Ma et al., 2011; Heldman et al., 2001).
The role of nanomaterials and nanostructured surfaces for improvement of biomaterial peculiarities in vascular surgery: a review
Published in Particulate Science and Technology, 2021
Marius Fodor, Lucian Fodor, Olimpiu Bota
The existence of the stent in the vessel is only necessary for a limited amount of time. Beyond this point, the stent may cause thrombogenicity and inflammation and may cause mechanical mismatch (O'Brien et al. 2016). The trend in the development of vascular stents in order to prevent late stent thrombosis is to eliminate the cause completely by using biodegradable stents with no polymer carrier. The first resorbable stents were fabricated from poly-L-lactic acid, which may take 18–24 months to resorb (Serruys et al. 2011; Diletti et al. 2012). Tyrosine polycarbonate incorporating iodine molecules is another substance used for biodegradable stents (Onuma and Serruys 2011). Desaminotyrosine polycarbonate polymer is a compound that is supposed to reduce the thickness of the stent struts while maintaining the radial strength (Koltowski et al. 2020). A meta-analysis comparing bioabsorbable polymer drug-eluting stents with durable polymer drug-eluting stents and bare-metal stents has shown improved results for the bioabsorbable stents compared to bare metal stents and first-generation drug-eluting stents (Palmerini et al. 2014).
Current perspectives on bioresorbable scaffolds in coronary intervention and other fields
Published in Expert Review of Medical Devices, 2021
Xinlei Wu, Sijing Wu, Hideyuki Kawashima, Hironori Hara, Masafumi Ono, Chao Gao, Rutao Wang, Mattia Lunardi, Faisal Sharif, William Wijns, Patrick W. Serruys, Yoshinobu Onuma
Coronary stents have undergone significant technological improvements for the last 40 years leading to superior clinical outcomes in patients with coronary artery disease. In 2002, drug-eluting stents (DES) were developed as an effort to address in-stent restenosis caused by bare-metal stents (BMS) [1,2]. A DES typically consists of a BMS processed with anti-proliferative drugs. As a consequence, DES has been proven to reduce the rates of target lesion revascularization (TLR) to less than 10% at a median of 14 months [3]. Although the current DESs exhibit excellent clinical endpoints [4], very late stent thrombosis remains an unpredictable complication of coronary revascularization procedures [5]. Also, the continuing neointimal response suggested a ‘late-catch up’ phenomenon, which might be caused by residual metal struts when the anti-proliferative agent is completely eluted. Furthermore, the permanent metallic stents within the vessel could result in stent fatigue fracture, preclude surgical revascularization, prevent expansive arterial remodeling, impair normal vasomotor reactivity, and jail side branches [6].
Device profile of the XIENCE V and XIENCE Sierra stents for the treatment of coronary artery disease: an overview of safety and efficacy
Published in Expert Review of Medical Devices, 2020
Andreas Mitsis, Marco Valgimigli
Percutaneous transluminal angioplasty (PTCA) was a revolution in the percutaneous management of coronary artery disease (CAD) [1]. Bare-metal stents (BMS) replaced the use of plain balloon angioplasty due to their proven superiority on mitigating the risks of acute complications (abrupt vessel closure) and restenosis due to elastic recoil [2]. Stenting with BMS resulted in almost 30% lower rate of restenosis in comparison with plain balloon angioplasty [3]. However, the use of BMS continued to carry a risk of in-stent restenosis (ISR) from 15% to 60% (depending on patient co-morbidities, vessel size, and lesion complexity) which mainly occurred due to excessive neointimal proliferation within the stented segment [4]. The prevention of restenosis triggered the development of drug-eluting stents (DES) which mainly release anti-proliferative agents from polymers directly engineered on the stent surface.