Pluronic F127 "nanoarmor" for stabilization of Cowpea mosaic virus immunotherapy

Our lab demonstrated that intratumoral Cowpea mosaic virus (CPMV) is a potent antitumor immunotherapy when used as in situ vaccine. As we pave the way for human clinical translation, formulation chemistry needs to be optimized for long-term storage of the drug candidate. In this work, CPMV was nanoengineered with Pluronic F127 to realize liquid and gel formulations which mitigate structural changes and RNA release during long-term storage. We evaluated the CPMV-F127 formulations for their stability and biological activity through a combination of in vitro assays and efficacy in vivo using a B16F10 murine melanoma model. Results demonstrate that both F127 liquid and gel formulations preserve CPMV structure and function follow-ing extended periods of thermal incubation at 4 degrees C, 25 degrees C, and 37 degrees C. Heat-incubated CPMV without formulation resulted in structural changes and inferior in vivo effi-cacy. In stark contrast, in vivo efficacy was preserved when CPMV was formulated and protected with the F127 "nanoarmor."