Poloxamers are large synthetic macromolecules or nonionic triblock copolymers composed of a central hydrophobic chain of polyoxypropylene flanked by two hydrophilic chains of polyoxyethylene. They are amphiphilic polymers (with both hydrophilic and lipophilic properties), which allows them to be formulated with vaccines in various scalable ways.
Vical has developed poloxamer formulations that enhance DNA delivery, which results in increased antigen production from the injected tissue.
Through an in vivo screen of different poloxamer-based formulations, poloxamer CRL1005 has been identified as an effective plasmid delivery system for DNA vaccines. In aqueous vehicles above a set temperature of approximately 10ºC, poloxamer CRL1005 self-assembles into nanoparticles. The hydrophobic cationic surfactant benzalkonium chloride can anchor onto the surface of those nanoparticles, which can then be coated with DNA. Poloxamer CRL1005-based DNA formulations have been shown to increase the production of antigens in animal studies as well as both the cellular and antibody responses to these expressed antigens. Poloxamer CRL1005 is a component of the therapeutic cytomegalovirus vaccine ASP0113.