Albumin-binding lipid-aptamer conjugates for cancer immunoimaging and immunotherapy

Monitoring dynamic changes in tumor immune markers are essential for predicting the therapeutic responses of tumors to immunotherapy, as well as other traditional therapies, such as chemotherapy and radiotherapy. Here, we designed a lipid-aptamer conjugate by employing a C18 chain to modify an aptamer targeting programmed cell death-ligand 1(C18-ap PDL1). The obtained C18-ap PDL1 could bind with serum albumin postintravenous injection to achieve prolonged blood circulation and enhanced in vivo stability without weakening its binding affinity toward PDL1. C18-ap PDL1 labeling with radionuclides, such as;Tc, could yield a nuclear imaging agent exhibiting much higher tumor-homing ability than bare aptamer. Notably, such radiolabeled C18-ap PDL1 could be utilized to visually monitor the dynamic changes in PDL1 expression postchemotherapy or radiotherapy within a few hours. Additionally, this C18-ap PDL1 could offer improved antitumor immune therapeutic responses,which are comparable with those of commercial anti-PDL1 antibodies at the same weight dosage. Thus, this article presented promising lipid-modified aptamers for cancer immunoimaging and immunotherapy.