Nanotechnology-enabled precision strategies for bladder cancer: from in vitro diagnostics to in vivo therapy.

Bladder cancer (BCa) management is challenged by high recurrence rates, therapeutic resistance, and the lack of integrated strategies for early diagnosis and effective treatment. Although nanotechnology has been widely explored in oncology, existing reviews largely discuss diagnostic and therapeutic applications separately, with limited attention to how nanomaterial design governs biological performance in the bladder-specific microenvironment. Here, we present a materials-oriented and problem-driven review that systematically connects nanomaterial design with functional outcomes across the diagnostic-therapeutic continuum in BCa. We highlight how tunable physicochemical properties, such as size, surface chemistry, and interfacial behavior enable enhanced urinary biomarker detection, high-resolution imaging, and efficient intravesical drug delivery under dynamic physiological conditions. Particular emphasis is placed on integrated nanotheranostic platforms that combine diagnosis, imaging, and therapy within unified systems, enabling real-time feedback and synergistic treatment. We further discuss key advances in nanocarrier-based chemotherapy, phototherapy, immunomodulation, and gene delivery, with a focus on overcoming bladder-specific barriers including urothelial impermeability, rapid urine-induced clearance, and tumor heterogeneity. In contrast to prior descriptive reviews, this work also addresses translational challenges such as biosafety, reproducibility, and scalable manufacturing, and outlines emerging directions including AI-assisted nanomaterial design and nano-enabled liquid biopsy. Overall, this review provides a conceptual framework linking nanomaterial engineering with clinical needs in BCa, aiming to guide the rational development of next-generation precision nanomedicine.