Cell membrane adhesive n-hexadecyl choline phosphate as vaccine delivery systems for anticancer immunotherapy

Abstract

In recent years, cancer immunotherapy as a new generation of cancer treatment strategy has displayed promising potential and attracted more and more attention. However, tumor-associated antigens if used alone could not induce potent immune responses. Therefore, efficient tumor treatment demands the assistance of vaccine delivery systems to elicit strong anti-tumor immune responses. In this study, a novel cell membrane adhesive vaccine carrier—n-hexadecyl choline phosphate (C16-CP) was synthesized and evaluated for the delivery of model antigen ovalbumin (OVA) and for anticancer therapy. Choline phosphate (CP) group is orientated opposite to and hence has electrostatic attraction with the phosphatidylcholine group of cell membrane component dipalmitoyl phosphatidylcholine. Moreover, CP group was hydrophobically modified with n-hexadecyl chain to prepare a cell membrane adhesive molecule C16-CP, which could adhere to cell membrane through electrostatic attraction and hydrophobic interaction. The CP group is positively charged at neutral pH environment. Hence, the cationic lipid C16-CP could interact with OVA through electrostatic attraction and hydrophobic interaction. In this work, the potential of C16-CP to assist antigen delivery was evaluated in order to develop a novel vaccine delivery system.