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

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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