Authors: T.P. Castor
Affilation: Aphios Corporation, United States
Pages: 362 - 365
Keywords: proteins, peptides, antigens, delivery, nanospheres, biodegradable, ploymers
Biologically adherent polymeric microsphere carriers have been shown to be effective in the oral delivery of proteins such as insulin and DNA plasmids. These microspheres are comprised of hydrophobic copolymers that appear to have a significantly longer residence time in the gastrointestinal tract as compared to conventional microspheres. While highly promising, the hydrophobic microspheres still present challenges in terms of manufacturing and formulation of a clinically acceptable product. Typically, the microspheres are produced from an organic solvent solution, which raises concerns about deleterious effects on the therapeutic proteins and residual organic solvent in the final product. We have avoided these difficulties by utilizing SuperFluids to form mono-disperse polymer nanospheres. SuperFluids are supercritical, critical or near-critical fluids with or without polar cosolvents such as ethanol. SuperFluids biodegradable polymer nanospheres can also be utilized for the controlled release of viral vaccine antigens. The use of SuperFluids reduces exposure of viral antigens such as HIV and Influenza to potentially denaturing organic solvents such as methylene chloride and ethyl acetate, and improves the stability of protein antigens in the body at ambient temperature for long periods, thereby enhancing the capability of nanoencapsulated vaccine antigens to induce the production of protective and neutralizing antibodies.