Triamcinolone :acetonide-controlled release urinary catheter: Localized delivery with anti-fibrotic and anti-inflammatory effects for preventing urethral stricture.

Urethral stricture remains a challenging urological condition due to its high recurrence rate and limited therapeutic efficacy. Triamcinolone acetonide (TA) has been shown to inhibit scar formation in the management of urethral stricture. However, current administration strategies, including local injection and topical catheter application, are limited by suboptimal drug stability and insufficient duration of efficacy. Therefore, we developed a controlled drug-release system by incorporating TA into polyether polyurethane (PEUR) and integrated it onto a urinary catheter to achieve sustained local drug delivery. Continuous TA release during the critical phase of wound healing was designed to suppress excessive scar formation and thereby reduce stricture recurrence. This novel catheter exhibited favorable material properties, including a smoother surface, enhanced hydrophilicity, and improved mechanical performance. In vitro release studies demonstrated an initial burst release of TA within the first week, followed by sustained drug release for up to 7 weeks. Both in vitro experiments and a rabbit urethral injury model demonstrated that TA can reduce the formation of fibroblasts in the injured urethra by suppressing the TGF-β/Smad2 signaling pathway and decreasing the secretion of pro-inflammatory cytokines, such as IL-6 and TNF-α, thereby inhibiting the formation of urethral scars. This novel catheter with a controlled-release function can significantly reduce the incidence of urethral stricture and exhibits promising potential for clinical translation.