Immunogenic dead cells engineered by the sequential treatment of ultraviolet irradiation/cryo-shocking for lung-targeting delivery and tumor vaccination.

Chemoimmunotherapy is a promising strategy in tumor treatments. In this study, immunogenic dead cells were engineered by the sequential treatment of live tumor cells with ultraviolet (UV) irradiation and cryo-shocking. The dead cells could serve as a lung-targeting vehicle and tumor vaccine after differential loading of the chemo-drug 10-hydroxycamptothecin (HCPT) and immune adjuvant Quillaja saponin-21 (QS-21) via physical absorption and chemical conjugation, respectively. After intravenous administration, the dead cells could be trapped in pulmonary capillaries and could fast release HCPT to enhance the drug accumulation in local tissues. Further, the immunogenic dead cells elicited antitumor immune responses together with the conjugated adjuvant QS-21 to achieve the elimination and long-term surveillance of tumor cells. In a lung tumor-bearing mice model, this drug-delivery system achieved synergistic antitumor efficacy and prolonged the survival of mice.