Ultrasound-programmable tumor extracellular vesicles delivery system for dual immune-epigenetic therapy against colorectal cancer metastasis.

Extracellular vesicles (EVs) are promising drug carriers for cancer therapy, but conventional engineering methods often suffer from limited efficacy and safety concerns. Here, we report a non-invasive strategy to generate tumor-derived EV using low-frequency focused ultrasound stimulation, termed US-EV. Brief ultrasound exposure markedly increased EV yield, enhanced tumor-homing capacity, and reduced nucleic acid cargo, thereby lowering potential nucleic acid-related safety risks. Proteomic analyses revealed activation of inflammatory and apoptosis-related pathways, accompanied by upregulation of adhesion molecules that promote EV biogenesis and targeting.

Functionally, US-EV induced immunogenic cell death and efficiently co-delivered a sonosensitizer (Hematoporphyrin monomethyl ether, HMME) and YTH N6-methyladenosine RNA-binding protein 1 (YTHDF1)-targeting siRNA to tumors. Upon ultrasound activation, HMME remodeled the tumor immune microenvironment, while siYTHDF1 mediated gene silencing and epigenetic reprogramming, overcoming dendritic cell resistance and enhancing cytotoxic T cell infiltration. This combinational approach suppressed both primary and metastatic tumor growth and elicited durable systemic antitumor immunity in preclinical models. Our ultrasound-triggered EV platform provides a safe, efficient, and translational strategy for metastatic colorectal cancer therapy.