UK researchers develop fridge-free hydrogel to store vital medicines

Article by Aniqah Majid

The University of Manchester
The gel can protect and maintain the properties of proteins at temperatures as high as 50oC

UK SCIENTISTS have developed a water-based gel that can store vital medicines, including the diabetes drug insulin, without the need for refrigeration.

Designed by researchers at the Universities of Manchester, Glasgow, and Warwick, the hydrogel protects and maintains the properties of proteins at temperatures as high as 50oC.

The technology could improve the accessibility of protein-based medicines to hot countries with little access to cold storage facilities.

Dave Adams, a professor at the University of Glasgow’s School of Chemistry, said: “The technology we’ve developed marks a significant advance in overcoming the challenges of the existing ‘cold chain’ which delivers therapeutic proteins to patients.”

He added: “The results of our tests are encouraging, going far beyond current hydrogel storage techniques’ abilities to withstand heat and vibration.”

Retaining vaccine function

Hydrogels have been used extensively by material scientists and biologists as a vessel for pharmaceutical agents.

The Covid pandemic accelerated interest in developing solutions to store cold chain medicines which tend to withstand a temperature range of 2oC–8oC.

In 2022, researchers from ETH Zurich and Nanoly Bioscience developed a polymer-based hydrogel to package vaccines to withstand temperatures of up to 65oC.

The team from the Universities of Manchester, Glasgow, and Warwick focused on retaining the functionality and stability of protein-based drugs, specifically insulin and beta-galactosidase, an enzyme with multiple applications in biotechnology.

Protein-based medicines must be kept cold to prevent deterioration, usually needing refrigeration and additives to maintain stability, something that can prove energy and material intensive for developing countries.

Trapping proteins

The hydrogel is made from small molecules called low molecular weight gelators (LMWG). These self-assemble in solution to form stiff fibres that can trap proteins and stop them from mixing – when proteins mix, it can lessen the effectiveness of the medicine.

When the hydrogel and protein are in a syringe, applied pressure breaks the brittle fibres and releases the protein, with the gel being caught in a filter.

Warming up samples of insulin to 25oC and rotating them at around 600 rpm, the researchers found the gel was able to recover the entire volume of the medicine and keep it intact.

The beta-galactosidase samples were stored at 50oC for seven days, and the team were able to retain 97% of the enzymes’ function compared to a fresh sample stored at a typical refrigeration of between 0oC and -20oC.

Taking it a step further, the team put protein samples suspended in hydrogel in the post, which spent two days in transit. They found the gels kept the proteins intact without any aggregation.

Matthew Gibson, a professor at the University of Manchester, said: “Separating the hydrogel components from the protein or proving that they are safe to consume is not always easy.

“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.”

Article by Aniqah Majid

Staff reporter, The Chemical Engineer

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