Cryo-shocked cancer cells for targeted drug delivery and vaccination.

Live cells have been vastly engineered into drug delivery vehicles to leverage their targeting capability and cargo release behavior. Here, we describe a simple method to obtain therapeutics-containing "dead cells" by shocking live cancer cells in liquid nitrogen to eliminate pathogenicity while preserving their major structure and chemotaxis toward the lesion site. In an acute myeloid leukemia (AML) mouse model, we demonstrated that the liquid nitrogen-treated AML cells (LNT cells) can augment targeted delivery of doxorubicin (DOX) toward the bone marrow. Moreover, LNT cells serve as a cancer vaccine and promote antitumor immune responses that prolong the survival of tumor-bearing mice. Preimmunization with LNT cells along with an adjuvant also protected healthy mice from AML cell challenge.