An effective stent for ureteral obstruction requires controlled swelling behaviour, sustained drug delivery, inhibition of bacterial adhesion, and performance characteristics that conventional stents frequently fail to attain. Two bi-layer bioresorbable stents (Carr/Alg and Ch/PVA) were developed using carrageenan (Carr) and chitosan (Ch) as the inner layer for drug diffusion and integrated with alginate (Alg) and PVA as the outer layer that provides controlled degradation and structural stabilization. Drugs, including aspirin (Asp) and dexamethasone (Dex), were incorporated facilitating drug delivery. Swelling analysis and degradation study of the stent in artificial urine over 18 days indicated the carrageenan/alginate (Carr/Alg) stent showed high fluid retention of 715.8%, compared to the chitosan/PVA (Ch/PVA) stent with 238.8% maintaining stable shape without excessive swelling. The cumulative drug release for Carr/Alg stent had the highest initial burst of 25% over 48 h, whereas Ch/PVA showed 23%, consistent with non-Fickian model. Surface morphology was analysed, confirming bi-layered structure and porous networks for structural stability. Bacterial adhesion was assessed using gram-negative Escherichia coli, demonstrating anti-adhesion behaviour, while bulging analysis demonstrated dimensional stability, indicating suitability under dynamic urinary tract conditions.
Rajagopal et al. (Sat,) studied this question.