This Phase I SBIR project is designed to develop new biodegradable hydrophilic coatings for ureteral stents. Ureteral stents are widely used to maintain drainage of the upper urinary tract and instrumental in management of stone disease, as well as in cases of other ureteral obstruction such as injury, fibrosis or malignancies. However, unlike cardiovascular stents, ureteral stents are recommended for use 3 months or less due to encrustation and biofilm formation. Over 75% of ureteral stents are encrusted at this 3 month time period, making removal difficult and causing patients pain. The best commercial coatings reduce encrustation thickness by 50% and extent of encrustion by only 22% over uncoated ureteral stents. This project focuses on novel coatings which release agents designed to minimize encrustation. In Phase I, two different agents were shown to reduce encrustation 65% over 4 weeks in vitro. In Phase II, one coating will be optimized for full scale use on ureteral stents and implanted in a 30 day GLP porcine study to prepare for FDA submission.
This proposal develops new coatings for ureteral stents which promise to reduce encrustation while the stent is in use. If long term use of a ureteral stent is currently recommended, they must be exchanged every 3 months and in many cases even within this timeframe the patient experiences flank pain and urinary discomfort. Better coatings for the ureteral stents may allow a longer timeframe before exchange as well as less pain and higher quality of life for patients.
