Separation

HOUGHTON — New research into virus separation methods could decrease the cost of creating vaccines and help bring new ones to the market faster.

Virus separation refers to the removal of cells and collection and concentration of virus for use as a vaccine production or the removal of the virus to prevent contamination of a protein product, like immunotherapies for cancer.

Caryn Heldt, Michigan Tech James and Lorna Mack Chair in Bioengineering has been researching alternative virus separation techniques for eight years.

“We are very much in development,” said Heldt. “We’ve been talking to a few companies but right now we are just developing the technology on a small scale in our lab.”

Heldt’s research focuses on moving away from a popular, but currently more expensive, virus separation method called chromatography. Chromatography uses high pressure liquid in a column of porous beads. The antibodies stick to the beads separating them. However, the viruses are often too large to latch on easily, and thus many are lost.

As an alternative, Heldt is experimenting with two new methods, flocculation and Aqueous two-phase extraction.

Flocculation involves causing the viruses to clump together, from there they can be filtered from other materials using a standard 0.2 micron filter and then collected.

“Normally that filter isn’t any good for viruses, they flow right though it, they’re so tiny,” Heldt said. “We’ve been using sugars and amino acids and we’ve been able to purify and recover infectious viruses with this system because the virus now doesn’t go through the filter but all the proteins and other parts of the cells we’re trying to get rid of will go through the filter.”

Aqueous two-phase extraction separates compounds similar to the way oil and water react.

“Our goal is to develop separation techniques that will…function for a variety of viruses and that way when a new vaccine is available for market. It’s more of a plug and play where you know the system that’s going to work to separate and purify it,” said Heldt.

Currently, new virus molecules must go through a full purification development process. But taking known methods that work for antibodies, only slight changes would be needed to target a different form of cancer or disease, she said.

The method could also help with purification in gene therapy, keeping the process safer for those receiving treatment.

Gene therapy refers to the removal of virus DNA from a virus shell which is then replaced with a gene that is missing from the body. The modified virus is used to infect the cells of the person with the missing protein, adding it to their cells. The end goal is to cure conditions like Hemophilia and has shown promise. Though uncommon, virus separation research is working to make the purification process more reliable and efficient.

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