10-Aug-2022 - Eidgenössische Technische Hochschule Zürich (ETH Zürich)

Hydrogel keeps vaccines alive

ETH Zurich and Colorado-​based start-​up to develop one step towards solving a global issue

Most vaccines require constant refrigeration during shipment to remain effective. An international research team led by ETH Zurich has now developed a special hydrogel that vastly improves the shelf life of vaccines, even without refrigeration. The development could save many lives and lower the cost of cold chains.

Nearly half of all vaccines go to waste. This is due to the logistical obstacles involved in transporting them to diverse regions of the world. Most vaccines require strict temperature regulation from the manufacturing line to injection into a patient's arm. Maintaining a constant temperature along the cold (supply) chain is a challenging feat in the best of circumstances. In Sub-​Saharan Africa and other developing regions, for example, limited transport infrastructure and unreliable electricity compounds the already immense challenges of delivering viable vaccines.

Rising to the challenge, scientists from ETH Zurich’s Macromolecular Engineering and Organic Chemistry Labs and entrepreneurs from Colorado-​based start-​up, Nanoly Bioscience worked together to develop a safe, versatile platform to increase the thermal stability of vaccines. Their aim? To vastly improve the distribution of viable vaccines and reduce the economic costs of the cold chain.

Like “Tupperware” for proteins

“Think of it like an egg,” explains Bruno Marco-​Dufort, a doctoral researcher in Professor Mark Tibbitt’s Macromolecular Engineering lab. “At room temperature or in the refrigerator the egg maintains its viscous-​like protein structure, but once it hits boiling water or the frying pan its structure changes permanently”. It is similar for the proteins in a vaccine - once exposed to certain temperatures they clump together. Cooling them down again will not reverse their denaturation – you cannot ‘un-​cook’ the egg.

So rather than altering mother nature, Marco-​Dufort and the research team developed a new type of hydrogel, the details of which were just published in the journal Science Advances. The gel is based on a biocompatible, synthetic polymer known as “PEG” that serves as a protective, “cloaking device” for very large - yet invisible to the naked eye - complex molecules such as the proteins found in vaccines, antibodies, or gene therapies. The packaging works kind of like a molecular Tupperware, encapsulating the proteins and keeping them separated. It enables the proteins to withstand a higher range of temperature fluctuations. Instead of the traditional +2 to +8 °C (35 to 45 °F) range for the cold chain, encapsulation allows for a range of 25 to 65 °C (75 to 150 °F). Most importantly, the encapsulated cargo is simply released by adding a sugar solution, enabling easy on-​demand recovery of the vaccines at their point of use.

Use in cancer research

In addition to a higher rate of vaccine viability, the real game changer of this new biomedical hydrogel technology is the potential economic effect it could have on reducing costs and health risks associated with the cold chain. “In 2020, the overall market for cold chain services (from manufacturing to distribution) was $17.2 billion and forecasted to rise,” the researchers reported. Rising costs pose potentially dire consequences for public health and public trust if vaccines arrive via a compromised cold chain.

“Most vaccines are sensitive to hot and cold. This creates a large barrier for global immunization campaigns, because vaccine distribution and administrative costs often exceed the costs of production,” explains Marco-​Dufort. While more investments will be needed to shore up the cold chain, encapsulation offers a cost saving solution that could be put towards production of more vaccines and thus, save more lives.

Yet, there is still a long way to go in terms of further research, safety studies, and clinical trials before the hydrogels can be implemented for vaccine distribution. Their more immediate use is for transporting heat sensitive enzymes used in cancer research, for example, or protein molecules for research in lab settings.
One step towards solving a global issue

While new biotechnologies and cost savings are a step in the right direction, there are still tremendous logistical, political, and socio-​economic challenges in resolving the global issues surrounding equitable vaccine distribution and vaccine hesitancy. Marco-​Dufort’s motivation is undeterred. His childhood experience living in the Democratic Republic of the Congo instilled a deep appreciation for the need for vaccines against infectious diseases, not just for Covid-​19, but also for Polio, Meningitis, and Ebola. He, more than most, is aware of the tremendous challenges people living in Sub-​Saharan Africa face in terms of access to vaccines where infectious diseases are still prevalent.

Mark Tibbitt, Bruno Marco-​Dufort, and the team’s work represent a substantive advancement in vaccine excipient development. Their work also offers a glimmer of hope for a positive societal impact. Even a small relief of the economic factors associated with the distribution of vaccines, medicines, and biomedical research could result in larger impacts down the road.

Facts, background information, dossiers

More about ETH Zürich

  • News

    Breaking down plastic into its constituent parts

    A team of ETH researchers led by Athina Anastasaki have succeeded in breaking down plastic into its molecular building blocks and in recovering over 90 percent of them. A first step towards genuine plastic recycling. The chemical industry has a long tradition of producing polymers. This inv ... more

    Like bacteria firing spearguns

    Biologists from ETH Zurich have discovered speargun-​like molecular injection systems in two types of bacteria and have described their structure for the first time. The special nanomachines are used by the microbes for the interaction between cells and could one day be useful as tools in b ... more

    New drug candidates identified in bacteria

    Using computer-​based genome analysis, researchers at ETH Zurich have now discovered a new class of natural products that might one day serve as antibiotics. Animals, plants, fungi and bacteria – each and every organism carries a whole armoury of chemical compounds that enable it to interac ... more

  • q&more articles

    Analysis in picoliter volumes

    Reducing time, costs and human resources: many basic as well as applied analytical and diagnostic challenges can be performed on lab-on-a-chip systems. They enable sample quantities to be reduced, work steps to be automated and completed in parallel, and are ideal for combination with highl ... more

    Investment for the Future

    This is a very particular concern and at the same time the demand placed annually on Dr. Irmgard Werner, who, as a lecturer at the ETH Zurich, supports around 65 pharmacy students in the 5th semester practical training in “pharmaceutical analysis”. With joy and enthusiasm for her subject sh ... more

  • Authors

    Prof. Dr. Petra S. Dittrich

    Petra Dittrich is an Associate Professor in the Department of Biosystems Science and Engineering at ETH Zurich (Switzerland). She studied chemistry at Bielefeld University and the University of Salamanca (Spain). After completing her doctoral studies at the Max Planck Institute for Biophysi ... more

    Dr. Felix Kurth

    Felix Kurth studied bioengineering at the Technical University Dortmund (Germany) and at the Royal Institute of Technology in Stockholm (Sweden). During his PhD studies at ETH Zurich (Switzerland), which he completed in 2015, he developed lab-on-a-chip systems and methods for quantifying me ... more

    Lucas Armbrecht

    Lucas Armbrecht studied microsystems technology at the University of Freiburg (Breisgau, Germany). During his master’s, he focused on sensors & actuators and lab-on-a-chip systems. Since June 2015, he is PhD student in the Bioanalytics Group at ETH Zurich (Switzerland). In his doctoral stud ... more

q&more – the networking platform for quality excellence in lab and process

The q&more concept is to increase the visibility of recent research and innovative solutions, and support the exchange of knowledge. In the broad spectrum of subjects covered, the focus is on achieving maximum quality in highly innovative sectors. As a modern knowledge platform, q&more offers market participants one-of-a-kind networking opportunities. Cutting-edge research is presented by authors of international repute. Attractively presented in a high-quality context, and published in German and English, the original articles introduce new concepts and highlight unconventional solution strategies.

> more about q&more

q&more is supported by: