A mucoadhesive-to-penetrating nanomotors-in-hydrogel system for urothelium-oriented intravesical drug delivery.

Intravesical therapy (IT) is widely used to tackle various urological diseases. However, its clinical efficacy is decreased by the impermeability of various barriers presented on the bladder luminal surface, including the urinary mucus layer and the densely packed tissue barrier. In this study, we report a mucoadhesive-to-penetrating nanomotors-in-hydrogel system for urothelium-oriented intravesical drug delivery. Upon intravesical instillation, its poloxamer 407 (PLX) hydrogel gelated and adhered to the urothelium to prolong its intravesical retention. The urea afterwards diffused into the hydrogel, thus generating a concentration gradient. Urease-powered membrane nanomotors (UMN) without asymmetric surface engineering could catalyze the urea and migrate down this concentration gradient to deeply and unidirectionally penetrate the urothelial barrier. Moreover, the intravesical hybrid system-delivered gemcitabine could effectively inhibit the bladder tumor growth without inducing any side effect. Therefore, our mucoadhesive-to-penetrating nanomotors-in-hydrogel system could serve as an alternative to IT to meet the clinical need for more efficacious therapeutics for urological diseases.