Ions have different migration rates depending on their total charge, size, and shape, and can therefore be separated. Ions are charged with a buffer which can be pH regulated so the ions can be positively or negatively charged, providing the mechanism for separation.
The technique is used particularly for macromolecules, such as proteins. A negative charge is added to these molecules so they move towards the positive electrode. Gel electrophoresis has been used over the ages as an analytical tool for protein content and structures in fields ranging from medicine to proteomics.
Preparative electrophoresis is a more involved process for large scale fractionation of proteins as in Plasma Protein Fractionation. The first such use in plasma fractionation was developed by Drs Nair and Wang in the form of Tangential Flow Electrophoresis in the late 90’s. They set up PrIME Biologics in Singapore which became the first cGMP accredited plant in the world using tangential flow electrophoresis as its capture step for Albumin in 2016.
Tangential Flow Electrophoresis, however, was invented some 50 years ago by Dr Joel Margolis. The process allows rapid isolation of proteins with relatively high yield but has manufacturing inefficiencies which cannot be overcome because of its flatbed configuration.
CyMES was invented and developed as a completely different way of separating protein molecules by the same scientists who developed Tangential Flow Electrophoresis. CyMES was developed for large scale manufacturing. Here the electrodes and membranes are configured in cylindrical architecture which allows maximum exposure of the membrane to molecules and making the system at least three times more efficient. Cooling is also more efficient because of the way the cooling buffer circulates with the cylindrical column. Furthermore, the cylindrical structure uses assymetric electrode and membrane configurations. Electrical field strength is used in a much more efficient form thereby allowing higher yield and rapid process times compared to any other form of electrophoresis or column chromatography. CyMES is the micro processor compared to valves for plasma fractionation.
The Biopharmaceuticial industry has evolved from microbial production of simple proteins such as insulin and somatotropin in the 1980’s to sophisticated systems for production of recombinant therapeutic proteins such as human FVIII. While the industry has witnessed major innovation in upstream (cell culture) bioprocesses, there has been little innovation in the downstream processing, and presents a significant bottleneck for the industry. Recently there have been innovative protein purification systems developed, including continuous chromatography, which can lead to faster and more efficient utilisation of chromatographic matrices, lowering cost of goods (COG). Chromatography has a major limitation in that separation of solutes is dependent on diffusion.
However, the ideal chromatography column geometry has always been thought of as having:
- an infinitely short bed height (to minimise operating pressures), and
- an infinite width (to maximise binding capacity).
CyMES meets all of the objectives above are can be described as the ideal separation system.It is clear that membranes approach this ideal architecture more closely than chromatographic matrices by having short bed heights (essentially the thickness of the membrane), which minimises back pressure. Transport of solute through membranes is convection driven, with no diffusion limitation. Binding sites in membrane adsorbers are exposed to the solutes (i.e. proteins) within short diffusion distances (film diffusion), in contrast with bead chromatography, where pre- and intra-particle diffusion play a major role in binding kinetics; the majority of bead ligands will be reached by solute only after large intraparticle diffusion distances.
Membrane-based separations, on the other hand, largely alleviate the mass transfer limitations seen with conventional chromatography. The solvent molecules with solute are convected through the membrane pores contacting the functional group, rather than having to diffuse through the bead to the ligand. Thus, diffusional path length is minimised, and mass transfer efficiency increases significantly. Recently, more efficient manufacture of membranes, with increased functional group density on the membrane, has seen this technology becoming more important in bioprocessing.
The CyMES technology uses electrical separation through an impermeable membrane which only allows passage of molecules in an electrical environment. The membranes themselves have tortuous path pores which act like a gating mechanism for the passage of these molecules.
Thus, it can be seen that the CyMES is the answer to efficient macromolecular separations using the same cylindrical configuration of Chromatography but without the restriction imposed by width of the cylinder and bed height.
The CyMES process:
- Significantly reduces production steps compared to current technology thereby reducing manufacturing costs;
- Eliminates the use of ethanol or other solvents. This provides significant environmental, safety and cost savings;
- Uses electrical field in a cylindrical electrophoresis configuration allowing for;
- Selective isolation of plasma proteins;
- High process yield;
- Increased level of protection against pathogen contamination;
- High level of product purity.
Aegros has lodged 4 provisional patents covering the CyMES and associated processes.