Coatings for Urinary Stents: Current State and Future Directions

Abstract Urinary stent coatings are a strategy to tackle certain complications associated with the use of biomaterials. The latest innovations in surface coatings focused on the prevention of those problems, thus reducing further costs with treatments. Urinary stents associated symptoms, infections and encrustation are considered the major challenges, and, in an attempt to prevent such morbidity, several strategies were developed. Hence, coatings have been designed to improve quality of life for patients, reducing the friction, inhibiting uropathogens survival or attachment on stents, and avoiding the deposition of urinary crystals that triggers encrustation. Currently for ureteral stents, hydrophilic and diamond-like carbon coatings are commercial options associated with an enhanced performance of devices, comparing with uncoated ones. These commercially available approaches are all anti-adhesive coatings, and, in the general overview, this type of strategy appears to be a superior alternative than bactericidal coatings. Designs that trigger uropathogen death are usually associated with higher toxicity, and, in some cases, it can even favor the development of microbial resistance, which can hamper the infection treatment. With the present knowledge about antimicrobial mechanisms and inspired by nature, more cutting-edge alternatives, able to confer antimicrobial properties to the inner and outer parts of stents, will surely appear.