Smart Dual-Targeted NRP-1/CAIX Nanoparticles with Sequential pH/ROS Responsiveness Overcome Tumor Microenvironment Barriers for Enhanced Penetration and Antitumor Efficacy

Suboptimal intratumoral penetration remains a major obstacle to the clinical translation of nanomedicines, underscoring the need for innovative nanoplatforms that enable precise tumor penetration. While tumor-penetrating peptides are commonly used to improve nanomedicine accumulation and permeability in tumors, their efficacy in hypoxic regions remains limited. Herein, four pH/ROS dual-responsive polymer prodrugs, modified with or without the tumor-penetrating peptide CRGDK and the CAIX ligand, were constructed. The stability, pH/ROS responsiveness, in vitro drug release properties, and cellular uptake of the resulting micelles were evaluated. Tumor penetration was investigated using multicellular tumor spheroids (MTSs) and the PANC-1 xenograft model. Antitumor efficacy was studied in normoxic and hyperoxic cells, MTSs, and the xenograft model. Results showed that the NRP-1/CAIX dual-targeted prodrug micelles (P1) achieved deep tumor penetration in hypoxic tumor regions. A sequential targeting strategy employing both a tumor-penetrating peptide and a CAIX ligand offers a promising approach for enhancing nanomedicine infiltration into deep tumor areas.