Hemin-lipid assembly as an artemisinin oral delivery system for enhanced cancer chemotherapy and immunotherapy

Although artemisinin (ART) has shown initial promise in cancer therapy, its therapeutic efficacy is limited by its low tumor inhibitory efficacy and unfavorable distribution. Considering the important role of heme in the specific parasite-killing effect of ART, we designed a liposomal nanostructure self-assembled from hemin-lipid (Hemesome) to co-deliver ART and hemin for cancer therapy. The synergistic chemotherapeutic and immunotherapeutic effects of hemin and ART were demonstrated both in vitro and in vivo. The liposome-like structure was relatively stable in the blood circulation and gastrointestinal tract environment, but dissociated in the tumor cell environment. The folic acid (FA) modification not only increased their efficiency for transport across the epithelium, but also increased their tumor accumulation. In mouse models, following oral administration of FA-Hemesome-ART nanoparticles (5 mg kg^-1 ART in total) every other day and intraperitoneal injection with a programmed death-ligand 1 antibody (aPD-L1, 70 μg per mouse in total), MC38 tumors were completely inhibited within 30 days. The cured mice remained tumor-free 30 days after rechallenging them with another inoculation of MC38 cells due to the strong immune memory effect.