Ultrastable antibody ionic liquids

Inventors

Slocik, Joseph M • Naik, Rajesh R. • Dennis, Patrick B

Assignees

United States Department of the Air Force

Abstract

A stable protein ionic liquid, comprising an anti-hemoglobin cation/anion pair. The anti-hemoglobin cation/anion pair may be an anionic polymer of poly(ethylene glycol) 4-nonylphenyl 3-sulfopropyl ether. The anti-hemoglobin cation/anion pair may further comprise a cationized anti-hemoglobin antibody, single-chain antibodies from camelids, antibody fragments, polyclonal Anti-horse spleen ferritin antibodies, monoclonal Anti-Flag antibodies, monoclonal Anti-HRP2 to Plasmodium falciparum, polyclonal Anti-neuropeptide Y, polyclonal Anti-human troponin, isotypes of antibodies, or combinations of multiple antibodies.

Core Innovation

The invention provides a stable, water-free protein ionic liquid comprising an anti-hemoglobin cation/anion pair. The ionic liquid is formed by chemically modifying proteins, such as antibodies, into ionic salts that maintain biological activity, high antigen recognition, specificity, and binding affinity comparable to native antibodies. This modification removes most or all water (at least 95%) without disrupting the protein structure or functions, resulting in stable liquids that resist extreme temperatures and enable refrigeration-free storage and handling.

The problem addressed arises from the inherent instability of most biological materials, especially antibodies, in aqueous environments. Water promotes protein degradation through hydrolysis and oxidation, destabilizes structure, and increases temperature sensitivity, leading to short shelf lives and the need for refrigeration during storage, handling, and transport. This refrigeration dependency is impractical in many regions lacking electricity and increases costs and logistical burdens, limiting access and usability of antibodies and other proteins.

The invention overcomes these challenges by cationizing aqueous proteins using positively charged crosslinkers in the presence of coupling agents, purifying these cationized proteins, and titrating them with biologically-compatible counter anionic polymers to form cation/anion pairs. After removing excess reagents and most water through dialysis and lyophilization, and controlled heating, a viscous, clear, heat-resistant, biologically active protein ionic liquid is produced that maintains antibody binding affinity and specificity. The protein ionic liquids are stable at room temperature and even at elevated temperatures up to about 200 °C.

Claims Coverage

The patent discloses two independent claims focused on compositions of stable protein ionic liquids involving an anti-hemoglobin cation/anion pair with specified features.

The independent claims cover compositions of protein ionic liquids comprising specific cation/anion pairs with anionic polymers and various cationized antibody forms, highlighting the novel stable ionic liquid antibody compositions.

Stated Advantages

Documented Applications