Breakthrough gel offers hope of fridge-free cold storage of key medicines

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Scientists have developed a new gel which they say can help store and distribute key therapeutics like insulin without the need for refrigerators or freezers.

The technology could significantly improve the accessibility of essential protein-based drugs in parts of the world where cold storage infrastructure may be lacking, researchers said.

It may also lead to better efforts to diagnose and treat more people with serious health conditions in developing parts of the world, according to the study, published in the journal Nature on Wednesday.

“The technology we have developed marks a significant advance in overcoming the challenges of the existing ‘cold chain’ which delivers therapeutic proteins to patients,” study co-author Dave Adams from the University of Glasgow said.

The special hydrogel is made mostly of water that stabilises proteins and protects their properties even at temperatures as high as 50C, scientists said.

Protein-based drugs are used to treat a range of conditions, from diabetes to cancer and, most recently, obesity.

But keeping them stable during storage and transportation has been a challenge as any heat-induced structural changes in the proteins may render them ineffective.

Manufacturers try to keep protein-based drugs in very cold temperatures to prevent their deterioration. This requires significant amounts of energy, limiting distribution in developing countries.

While hydrogels have emerged as a potential solution to store and transport proteins at warmer temperatures, separating the gel components from the proteins has proved a challenge.

“Our breakthrough eliminates this barrier and allows us to store and distribute proteins at room temperature, free from any additives, which is a really exciting prospect,” Matthew Gibson, another author of the study, said.

Scientists built the hydrogel using a material called low molecular weight gelator, or LMWG, which forms a three-dimensional network of long, stiff fibres.

When proteins are added to the hydrogel, they become trapped in the spaces between the fibres in an easily reversible manner.

In these spaces the protein molecules are unable to mix and aggregate, a process which normally limits their effectiveness as medicines. Since the gel fibres are brittle, the protein molecules can also be easily released.

When the protein-filled gel was stored in an ordinary syringe with a special filter, merely pushing down on the plunger broke the fibres and released the protein.

In the latest study, researchers showed the gel could store two medically important proteins: insulin, used to treat diabetes, and beta-galactosidase, an enzyme with numerous applications in biotechnology and life sciences.

Insulin must normally be kept cold and still as any heating or shaking can make it ineffective. The new hydrogel could make the diabetes drug withstand warming up to 25C and rotation at 600 revolutions per minute, “a test far beyond any real-world scenario”, researchers said.

The entire active volume of insulin could be recovered from the hydrogel after the test, they noted.

Scientists could also store beta-galactosidase in the hydrogel at a temperature of 50C for seven days, a level of heat exceeding any realistic temperature involved in its real-world transport.

When the enzyme was extracted from the gel, researchers found it retained 97 per cent of its function.

In a third test, scientists sent proteins suspended in hydrogel via post to a location that took two days of transit.

Here too, they found the gel’s structures remained intact and prevented the proteins from aggregating.

Researchers expect their findings to have major implications in diagnostics and pharmaceutical industries.