Combination of oxaliplatin and POM-1 by nanoliposomes to reprogram the tumor immune microenvironment.

Some chemotherapy can damage tumor cells, releasing damage-related molecular patterns including ATP to improve immunological recognition against the tumor by immunogenic cell death (ICD). However, the immune-stimulating ATP may be rapidly degraded into immunosuppressive adenosine by highly expressed CD39 and CD73 in the tumor microenvironment, which leads to immune escape. Based on the above paradox, a liposome nanoplatform combined with ICD inducer (oxaliplatin) and CD39 inhibitor (POM-1) is designed for immunochemotherapy. The liposomes efficiently load the phospholipid-like oxaliplatin prodrug, and the cationic charged surface could adsorb POM-1. Rationally designed DSPE-PEGn-pep, on the one hand, could cover and hide POM-1 to avoid systematic toxicity and, on the other, achieve a response and charge reversal to favor POM-1 shedding and tumor deep penetration. This combination maximizes the ICD effect, and takes two-pronged advantage of stimulating the immune response and relieving immune suppression. The designed POL can effectively inhibit the growth of in situ, lung metastasis and postoperative recurrence melanoma model and form long-term immune memory. With the powerful clinical transformation potential of nanoliposome platforms, this new synergistic strategy is expected to enhance anticancer effects safely and effectively.