Aphios Corporation

Protein Nanoparticles

Protein Nanoparticles Aphios Corporation’s protein nanoparticles technology platform utilizes the expansive energy of SuperFluids™ to disaggregate or comminute protein crystals and amorphous powders into monodisperse nanoparticles [U.S. Patent No. 6,051,694, April 18, 2000]. SuperFluids™ encompass gases such as carbon dioxide which, when compressed, exhibit enhanced thermodynamic properties of solvation, selection and expansion.

Impact of Pressure: In the example shown for bovine serum albumin (BSA), protein size reduction increases non-linearly with pressure, approaching an asymptote between 3,000 and 4,000 psig for carbon dioxide. This trend is supported by the mechanism that higher pressures will result in higher expansive forces. The data indicates that extremely high pressures are not required for efficient protein comminution utilizing this technology.

Impact of Protein Type: The optimal conditions established for the SuperFluids™ comminution of insulin were utilized to evaluate the impact of protein type. This evaluation, shown in the adjacent table, indicates that the process is extremely robust for a wide range of proteins, molecular weights and particle sizes. Some fine-tuning may be required for specific proteins.

Impact on Bioactivity: As shown for insulin, the protein nanoparticles retain full activity after processing. For certain proteins, biological activity is enhanced because active sites are more exposed after comminution.

Aphios’ patented SuperFluids™ PNP (protein nanoparticle) process forms monodisperse protein particles without having to first dissolve the protein in a liquid solvent. The process is thus not constrained by limited solubility in benign solvents such as ethanol that may be used with other supercritical fluid techniques, and the utilization of large volumes of liquids that limits other techniques such as spray drying. The process also produces a Joule-Thompson cooling effect, and thus avoids heat associated with milling techniques that can cause protein degradation and contamination by metal particles. The SuperFluids™ PNP process is simple and scalable.