Metabolic Modulation of Intracellular Ammonia via Intravesical Instillation of Nanoporter-Encased Hydrogel Eradicates Bladder Carcinoma

Abstract

Tumor protein 53 (TP53) mutation in bladder carcinoma (BC), upregulates the transcription of carbamoyl phosphate synthetase 1 (CPS1), to reduce intracellular ammonia toxicity. To leverage ammonia combating BC, here, an intravesically perfusable nanoporter-encased hydrogel system is reported. A biomimetic fusogenic liposomalized nanoporter (FLNP) that is decorated with urea transporter-B (UT-B) is first synthesized with protonated chitosan oligosaccharide for bladder tumor-targeted co-delivery of urease and small interfering RNA targeting CPS1 (siCPS1). Mussel-inspired hydrogel featured with dual functions of bio-adhesion and injectability is then fabricated as the reservoir for intravesical immobilization of FLNP. It is found that FLNP-mediated UT-B immobilization dramatically induces urea transportation into tumor cells, and co-delivery of urease and siCPS1 significantly boosts ammonia accumulation in tumor inducing cell apoptosis. Treatment with hybrid system exhibits superior anti-tumor effect in orthotopic bladder tumor mouse model and patient-derived xenograft model, respectively. Combined with high-protein diet, the production of urinary urea increases, leading to an augmented intracellular deposition of ammonia in BC cells, and ultimately an enhanced tumor inhibition. Together, the work establishes that cascade modulation of ammonia in tumor cells could induce tumor apoptosis and may be a practical strategy for eradication of TP53-mutated bladder cancer.