A Lysosome-Targeting Self-Condensation Prodrug-Nanoplatform System for Addressing Drug Resistance of Cancer.

Lysosome-targeting self-assembling prodrugs had emerged as an attractive approach to overcome the acquisition of resistance to chemotherapeutics by inhibiting lysosomal sequestration. Taking advantage of lysosomal acidification induced intracellular hydrolytic condensation, we developed a lysosomal-targeting self-condensation prodrug-nanoplatform () system for overcoming lysosome-mediated drug resistance. Briefly, the designed hydroxycamptothecine (HCPT)-silane conjugates self-assembled into silane-based nanoparticles, which were taken up into lysosomes by tumor cells. Subsequently, the integrity of the lysosomal membrane was destructed because of the acid-triggered release of alcohol, wherein the nanoparticles self-condensed into silicon particles outside the lysosome through intracellular hydrolytic condensation. Significantly, the system reduced the half-maximal inhibitory concentration (IC) of HCPT by approximately 4 times. Furthermore, the system realized improved control of large established tumors and reduced regrowth of residual tumors in several drug-resistant tumor models. Our findings suggested that target destructing the integrity of the lysosomal membrane may improve the therapeutic effects of chemotherapeutics, providing a potent treatment strategy for malignancies.