Hydrogel Coatings for Heart Stents

Abstract

Heart stents are medical devices used to keep or expand the lumen of arteries. For more than the last three decades, percutaneous coronary intervention (PCI)‐based stent placement was applied as a primary choice in treating coronary artery diseases (CADs). Despite the success in relieving the symptoms of narrowed or weak arteries, bare metal stent placement is inevitably associated with restenosis, leading to stent failure in a relatively short timescale. To overcome this problem, bioactive‐containing polymer layer is coated on the stents, the so‐called drug‐eluting stent (DES), had been designed and successfully used to lower the restenosis rate. The in situ delivery of the active substances and/or the surface functionalities from the coatings of stents can facilitate re‐endothelialization, anti‐platelet aggregation, anti‐inflammation, and anti‐thrombosis and reduce the potential risk of PCI procedure to the surrounding tissues. Among the various coating strategies, hydrophilic polymeric hydrogel coatings show unique advantages such as capability of loading hydrophilic bioactives and/or cells, moldable softness to cell modulus, and tight fixation to arteries after placement. Consequently, hydrogel coating for heart stents are attracting more attention. This review aims at providing a timely summary and outlook for hydrogel coatings of heart stents.