Comparison of Ureteral Stent Biomaterials: Encrustation Profile inLithogenic Artificial Urine Models

ABSTRACT: Ureteral stent encrustation significantly limits indwelling time and can lead to downstream urological problems.However, no ideal polymeric biomaterials have been shown to completely resist encrustation in long-term urine exposure. Recently,2-hydroxyethyl methacrylate (HEMA)-coated Pellethane was reported as a promising biomaterial resistant to encrustation. Thisstudy compared HEMA-coated Pellethane to commercially available stents under two different artificial urine environments. Toevaluate the degree and composition of encrustation on HEMA-coated Pellethane, Boston Scientific Tria, Bard InLay Optima, CookUniversa Hydrogel, and Cook Black Silicone stents were used at various dwelling times in two different artificial urine environments.In a batch−flow model, samples of stents were suspended in an artificial urine solution (AUS) at 37 °C. Every 24 h for 11 weeks,50% of the AUS would be replaced with fresh components using a programmable peristaltic pump system. The stent materials wereremoved at suitable time intervals and air-dried for 24 h under sterile conditions before follow-up analysis. SEM was used to assessthe degree of encrustation, and inductively coupled plasma mass spectrometry (ICP-MS) was employed to quantify the encrustedcompositions, specifically for calcium, magnesium, and phosphorus. We measured the weight gain over time due to encrusteddeposits on the stents and quantified the amount of Ca, Mg, and P deposited on each encrusted stent. After the 11 week trial,HEMA-coated Pellethane showed the most average mass change. SEM showed that HEMA-coated Pellethane was fully encrusted injust 2 weeks in the AUS environments, and ICP-MS showed that Ca is the most abundant deposit. Among all the tested stents, BlackSilicone performed the best. The two AUSs were formulated to encrust more rapidly than physiological conditions. HEMA-coatedPellethane is not an ideal stent material, while silicone is a promising material for advancing ureteral stents

※I conducted the same research and obtained similar results. The polymer I developed showed outstanding effectiveness. It also exhibited antithrombotic properties.