Scheme 1.

Schematic illustration of inhalable CAR exosomes derived from CAR-T cells as PTX carriers for treating lung cancer. A Preparation process of PTX@CAR-Exo. B Antitumor effect of inhalable PTX@CAR-Exo against lung cancer. CAR-T cell-derived exosomes (CAR-Exos) inherited the targeted cytolytic effects from parental cells by releasing granzyme B and perforins. The loaded PTX was delivered into the tumor area to stimulate immune responses. In contrast to conventional CAR-T cell therapy and intravenous administration of PTX, the inhalable PTX@CAR-Exos used in an orthotopic lung cancer model exhibited superior antitumor effects and improved the bioavailability of both CAR-Exos and PTX, with decreased systemic toxicity