Ligand‐Ratio–Tuned DNA Nanocarriers Overcome Bladder Barriers for Ultralow‐Dose Intravesical Therapy

Effective delivery to target cells across biological barriers requires coordinated integration of multiple surface functionalities, yet such integration remains difficult to control in nanoscale systems. This challenge is particularly evident in intravesical delivery, where selective tumor-cell engagement must be coupled with efficient transport through the glycosaminoglycan/mucus-associated luminal environment. Here we present a ratio-tunable DNA framework drug carrier (dFDC) that enables precise control over two orthogonal surface modules: an Sgc8 aptamer for targeting and a fluorocarbon (F-C) chain for barrier transit. By programming their valency across 30 external sites of an icosahedral framework, we identify a nonlinear cooperative regime in which transport, uptake, and cytotoxicity are jointly optimized. Performance is governed by the relative proportion of functional modules rather than their absolute density. At the optimal Sgc8/fluorocarbon configuration, the carrier enhances diffusion in chondroitin sulfate, improves transport across a GAG-associated epithelial barrier model, and increases tumor-cell killing after barrier transit. In orthotopic models, this dFDC achieves complete tumor remission at ∼1/1500 of the clinical gemcitabine dose with no recurrence over 60 days. This work introduces ligand-ratio engineering as a general strategy for balancing orthogonal transport requirements across hierarchical biological barriers.