Gradipore has been granted US patent 6,464,851 for its core technology, Gradiflow, for the removal of biological contaminants from biological samples. Gradiflow is a unique membrane-based separation technology that allows molecules of interest to be isolated with high purity and yield. Gradiflow has shown potential to remove a wide variety of pathogens and is currently under evaluation by leading biotechnology and blood safety companies.

The transmission of pathogens via biological samples such as blood is a major and ever increasing problem. The rapid emergence and proliferation of HIV and Hepatitis B and C demonstrate the vulnerability of the blood supply to previously unknown pathogens. Screening tests for such pathogens can take years to develop. Currently, blood products intended for transfusion are only screened for four viruses and one bacterium. Hence, Gradiflow's ability to remove a wide variety of pathogens, including both enveloped and non-enveloped viral contaminants, is therefore of particular importance.

Certain pathogen removal systems for blood products that are currently in development utilize additives that treat or inactivate pathogens via chemical means and others require an additional "wash" step to remove the inactivated pathogen. Gradiflow technology has the potential to offer a unique advantage when compared to these systems, as it removes pathogens directly from the biological material. In this manner, the resultant biological material is significantly safer, and does not require the need for further processing.

"Securing this patent is a significant event for Gradipore because it solidifies the intellectual property for our core technology, Gradiflow, and paves the way for its use in viral removal applications," said Robert Lieb, Global CEO and Vice Chairman of Gradipore Inc. "This is an important first step as we strongly believe that the technology will revolutionize commercial scale pathogen removal for biological products due to its safety, ease of use, and ability to be scaled up to commercial processing levels."

Gradiflow technology is an advanced electrophoresis process that is comprised of two circulating streams, Stream 1 and Stream 2. The two streams are separated by a separation membrane and confined by restriction membranes. In an electric field a molecule will move towards the electrode of opposing charge. The electrodes are positioned so that Stream 1 contains molecules with a positive charge and Stream 2 molecules that are negatively charged. Charged molecules can be moved between the streams when a current is applied. This allows the separation of specific molecules from a complex mixture. Using Gradiflow, molecules can be separated by charge and size.

Other separations applications of Gradiflow technology include antibodies, prefractionation, recombinant proteins and plasma proteins. Gradiflow technology has already been used to separate proteins and to separate viruses and cells from proteins. Gradiflow has a wide range of applications in research, scientific and commercial production including blood purification and biological drug manufacturing. Unlike other large-scale blood purification technologies, Gradiflow can purify proteins and remove viral and bacterial pathogens simultaneously. These are currently multi-billion dollar markets of which the separation costs in many cases represent over 60% of the total costs of manufacture.