Triple-Targeting Cascade Nanoplatform Enhances Tumor Stromal Permeation with Intracellular Accumulation

Nano-based drug delivery systems often encounter challenges in insufficient tumor cell internalization, particularly in deep cells, due to dense tumor stroma, which limits drug delivery efficiency and antitumor efficacy. Here we present a smart nanoplatform (Trans-btND) with an onion-like multilayered structure, comprising a negatively charged heparin outer layer, a hyaluronidase (HAase) sublayer, and a positively charged reactive oxygen species (ROS)-responsive drug-loaded core. This design enables a triple-targeting strategy for effective tumor cell internalization: (i) heparin-mediated active targeting, driven by the affinity between heparin and overexpressed heparanase, promotes Trans-btND accumulation at tumor sites; (ii) charge-reversal-triggered tumor cell targeting, induced by the sequential degradation of heparin and HAase layers, facilitates cellular uptake via electrostatic interactions; (iii) ROS-activatable targeting, initiated by elevated intracellular ROS levels, enables precise cytosolic drug release. Notably, during the process, Trans-btND undergoes stepwise size reduction, intracellular transcytosis, and HAase-mediated stromal degradation, thereby promoting deeper tumor penetration. Therefore, Trans-btND with enhanced tumor targeting and stroma penetration can significantly augment delivery efficiency and amplify antitumor potency, providing a promising strategy for cancer therapy.