In Vitro Study Explores Potential Feasibility of Mitomycin-Coated Biodegradable Ureteral Stent

A significant challenge incurred in the treatment of low-grade upper tract urothelial carcinoma (UTUC) is the limited and difficult administration of adjuvant therapy, prompting researchers to find improved delivery methods.

“In response to the clear need to design new intracavitary chemotherapy instillation systems for adjuvant treatment of low-grade UTUC, gels and ureteral stents that can deliver chemotherapeutics have been developed,” explained researchers.

Authors of a study published in Polymers, shared results from their in vitro experimental study in which they assessed the feasibility of a proprietary biodegradable ureteral stent coated with a silk fibroin matrix for the controlled release of mitomycin c.

The study was organized into 3 main protocols: (1) comparing 2 combinations of biodegradable polymers and copolymers for the manufacture of the stent itself prior to coating; (2) the silk fibroin coating; and (3) assessing the release, concentration, and degradation of 2 mitomycin formulations.

“Our results confirm that the silk fibroin matrix is able to coat the biodegradable stent and release mitomycin for between 6 and 12 hours in the urinary environment,” said researchers. “There was a significant delay in the degradation rate of silk fibroin and mitomycin-coated stents compared to bare biodegradable stents, from 6–7 weeks to 13–14 weeks.”

Authors also found the range of pH changes in their experiment remained within in a normal range, which is significant as drastic changes in urinary pH related to stent encrustation or crystal deposition that can lead to urinary lithiasis.

An additional point of interest is the thickness of the silk fibroin and mitomycin C coated stent, despite a statistically significant increase, is not expected to be an obstacle to clinical application.  

“The addition of mitomycin C to the coating of silk fibroin stents could be an attractive approach for intracavitary instillation in the upper urinary tract,” concluded researchers, noting that more research is needed.

Reference:
Soria F, Aznar-Cervantes SD, de la Cruz JE, et al. Assessment of a coated mitomycin-releasing biodegradable ureteral stent as an adjuvant therapy in upper urothelial carcinoma: a comparative in vitro study. Polymers (Basel). 2022;14(15):3059. Published Jul 28, 2022. doi:10.3390/polym14153059