Drug-eluting Bioresorbable Ureteral Stent by CO2 Impregnation

Ureteral stents are indispensable tools in urologic practice. The main complications associated with ureteral stents are dislocation, infection, pain and encrustation1. Bioresorbable ureteral stents are one of the most attractive designs with the potential to eliminate several complications associated with the stenting procedure. In these work we hypothesize the impregnation of Ketoprofen, by CO2­impregnation in a patented bioresorbable ureteral stent previous developed in our group and validated in a pig model2. It was evaluated of the in vitro elution profile in artificial urine solution(AUS) during degradation of a bioresorbable ureteral stent loaded with ketoprofen. The bioresorbable ureteral stents was developed according Barros et al2. The bioresorbable ureteral stents with each formulation: alginate­based, gellan gum­ based(10mg) were placed in high­pressure vessel with 10mg ketoprofen. The impregnation conditions used were 100bar, 2h and different temperatures were studied (35oC,40oC and50oC). The impregnation was confirmed by FTIR and DSC. The in vitro release studied revealed an influence of the temperature in the impregnation, with 50oC operating condition to obtain higher yield. Higher yield are obtained for gellan gum­ based comparing the polymers used. According to the kinetics results (released exponent(n) was between 0.45<n<0.89)3 this systems are very promising for release ketoprofen in the first 72h in AUS. The non­cytotoxicity characteristic of the developed ketoprofen­eluting bioresorbable ureteral stents was evaluated in L929cell­line by MTS assay and demonstrated the feasibility of this product as a medical device. This study demonstrated the possibility of combined eluting­drugs with a bioresorbable ureteral stents for different urological targets.