Gelatin-based covalently crosslinked hydrogel.
© Fraunhofer IGB
Gelatin-based covalently crosslinked hydrogel.

We develop materials that can perform a specific function in the biological milieu as hydrogels. Biological molecules or synthetic polymers serve as starting materials.

A hydrogel is a water-containing and at the same time water-insoluble polymer. The polymer can be of natural origin, such as gelatin, or of artificial origin. Examples include polaxamers, block polymers of ethylene oxide and propylene oxide. Hydrogel molecules are chemically linked to form three-dimensional networks, for example, by ionic or covalent bonds or entanglements of the polymer chains. In water, they swell due to an incorporated and hydrophilic polymer component and thus obtain a high increase in volume. In some gels, it comes up to 90 percent water content.

Production of hydrogels by means of UV crosslinking.
© Fraunhofer IGB
Production of hydrogels by means of UV crosslinking.

Our know-how in the production of synthetic polymers for hydrogel production covers all polymerization processes such as radical, ionic and step growth polymerization. Likewise, we use existing biomaterials, which are functionalized depending on the application. For example, we work with the following materials:

  • Gelatin
  • Chitosan
  • Hyaluronic acid
  • Alginates
  • Synthetic hydrogels, e.g. based on polyethylene glycol

Adapting the properties of hydrogels

We convert biomaterials such as gelatin or chitosan into new custom-fit hydrogels by polymer analog reaction. In this way, we introduce functional groups into the base materials and adapt their properties to the respective requirements. We use chemical crosslinking technologies to build tissue-like hydrogels. Through controlled crosslinking, we obtain hydrogels with adjustable mechanical and biological properties.

For the assembly of hydrogels from synthetic polymers, polyethylene glycol is often used as a non-toxic, non-immunogenic, hydrophilic and highly elastic material. At Fraunhofer IGB a novel PEG derivative was synthesized, which contains a crosslinkable thiol group at each repeating unit which can be crosslinked e.g. by Michael addition. In addition, the properties of the hydrogel, such as swellability and mechanical stability, can be easily adjusted via the ratio of the reagents.

Biopolymer hydrogels of different compositions as tissue matrices with adjustable biological and mechanical properties.
© Fraunhofer IGB
Biopolymer hydrogels of different compositions as tissue matrices with adjustable biological and mechanical properties.

Applications for hydrogels

Hydrogels play a role in a considerable number of biotechnological developments or applications in medicine.

  • Medical devices, e.g. membranes, fibers and nonwovens
  • Textile coating
  • Biofunctional particles
  • Implant development
  • Drug release
  • Biosensor technology
  • Tissue Engineering

Nanogel biosensors for quick and safe pathogen diagnostics

CAD drawing of a test chip
© Fraunhofer IGB
CAD drawing of a test chip
© Fraunhofer IGB
Die Erreger-DNA wird an mehreren Stellen in einem Hydrogel-Spot auf den Chip gedruckt und hierdurch stabilisiert. Das Testsystem wird damit sensitiver und kann auf verschiedene Erreger ausgeweitet werden.

An important tool for detecting and treating diseases caused by viruses and bacteria is their rapid and reliable identification. The crux of many tests: rapid antigen tests provide results quickly, but with great inaccuracy; PCR tests, however, are more accurate, but take considerably longer.  

Our development

Fraunhofer IGB, in cooperation with the Fraunhofer Institute for Production Technology IPT and the Fraunhofer Center for Manufacturing Innovation CMI in Boston (USA), has developed an alternative that is both fast and accurate. In our approach, we use the RT-LAMP technology (reverse transcription loop-mediated isothermal amplification) for the rapid amplification of the viral or bacterial RNA for subsequent detection. The highlight: by combining it with our patented, printable hydrogel, the test becomes much more sensitive and many pathogens can be detected simultaneously (multiplexing).

Advantages and technological readiness

Our solution distinguishes itself from other current products because of various advantages:

  • Fast and accurate result
  • No sample preparation required, which means that tests could also be carried out at home
  • Printing process enables spatial multiplexing allowing testing for many different pathogens within one examination

The feasibility of our approach has been successfully demonstrated (TRL 3-4). The next step is to optimize the sensor layout and transfer it to cost-effective, scalable production processes.


Since we developed the system as a modular system, it is easily adapted to customer-specific issues such as new pathogens. If you are interested in the joint development of a market-ready product, please do not hesitate to contact us.

We see areas of application wherever information is needed quickly about whether and with which pathogens a person is infected. This can be the case, for example, at entrance control in areas with an increased risk of infection (hospitals, care facilities). By adjusting the pathogen spectrum on the sensor, our system is also suitable for monitoring microorganisms in the environment and food production or for quality control in pharmaceutical production.

One of the main functions of our patented hydrogel is the stabilization of biomolecules (proteins, enzymes). The hydrogel therefore also offers great advantages for the development of other products, e.g. other test assays, formulations or surface modifications.

Further information


June 2021 – December 2022


Nanogel biosensors for fast and safe pathogen diagnostics

Rapid antigen tests quickly provide a result on a corona infection – however, unlike the PCR test, the accuracy leaves much to be desired. A consortium of the Fraunhofer Institutes for Production Technology IPT, for Interfacial Engineering and Biotechnology IGB and the Fraunhofer Center for Manufacturing Innovation CMI in Boston (USA) is therefore researching an alternative that is both fast and accurate. The Pathogen Analyzer uses the LAMP test in a patented, printable hydrogel and is quickly transferable to other pathogens.



Protocols for standardized bioprinting

When it comes to closing the implant supply gap, the most promising solution lies in 3D bioprinting. This is an additive manufacturing process that prints living cells in a biocompatible substrate, layer by layer, into stable, well-defined 3D constructs. These 3D-printed structures are currently the subject of research and development in the diverse fields of regenerative medicine and tissue engineering, and are also becoming increasingly important in industrial applications.


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