PIC-gel in petrischaaltje
PIC-gel in petrischaaltje

Research projects involving the PIC gel

Project member(s)
Dr P.H.J. Kouwer (Paul)
Project type

Biomimetic Hydrogels

Hydrogels are omnipresent in our lives. They are indispensable ingredients in food and cosmetics and used in for instance oil drilling and tissue engineering. Hydrogels also play a key role in the mechanical properties of our cells (cytoskeleton) and the extracellular matrix. These gels have intriguing properties: they have a fibrous architecture that allows for relatively stiff materials at very low concentrations as well as a large pore size (which benefits nutrient and protein transport). A unique property associated to the architecture is that the materials become stiffer under stress, up to 100 fold, which is thought to aid in tissue protection and cell-cell communication.

PIC gel

In 2013, Radboud researcher Paul Kouwer and his team have developed a synthetic gel (PIC) with the properties of a biological gel (Nature 2013). As a synthetic material, it is possible to have full control over the structure and the mechanical properties (Nature Commun. 2014 and Adv. Funct. Mater. 2016). In analogy to the cytoskeleton, researchers can further control the mechanics using multi-component gels (Nature Commun. 2017) or with minute external stimuli (Nature Commun. 2019, Nano Lett. 2021, Adv. Mater. 2022).

Unique features of the PIC gel

The unique feature of the PIC gel is that it combines the advantages of synthetic materials (reproducible, tailorable) with the physical properties of biological materials such as collagen and fibrin. The research team showed that this material mimics key properties of collagen, such as nonlinear mechanics (Adv. Funct. Mater. 2021, Bioactive Mater. 2022) and force transmission on cellular contraction (PNAS 2023). These properties are not found in any other synthetic material. The research team is constantly looking for innovative approaches to further develop our material (Nat. Mater. 2022).


Its strong biomimetic properties makes PIC gels very suited for a wide range of biological applications. Paul Kouwer and colleagues are exploring many of them in parallel, for instance stem cell engineering (Das et al. Nature Mater. 2016, Biomacromolecules 2019, ACS AMI 2020), fibrosis assay development (ACS AMI 2022, Adv. Therap. 2022) and to improve tissue culture techniques (Adv. Healthcare Mater. 2022).

They would like to the develop the PIC gel to become a suitable matrix for more complex cultures, such as organoid. Paul Kouwer and colleagues (Adv. Sci. 2020) in Utrecht (Ye et al. Adv. Funct. Mater. 2020) and Groningen (Schaafsma et al Front. Mol. Biosci. 2023) made the first promising steps.

In addition, the team works on applying PIC gels in the in vivo context, particularly in wound healing (Biomaterials 2018, Biomater. Adv. 2022) and treatment of periodontitis (J. Control. Release 2020, Acta Biomater. 2020).

The PIC gel could make it possible to replace currently used animal-based materials (BM extracts) with well-defined synthetic materials, saving millions of production mice every year (PNAS 2023).

In 2024, Melissa van Velthoven has received her PhD from Radboud University for her research on improving recovery after surgery for pelvic organ prolapse, conducted in collaboration with Amsterdam UMC. Van Velthoven's research explores the potential of the synthetic PIC gel to enhance the healing process and reduce the need for repeat surgeries.

Ongoing research projects involving the PIC gel

Transition to Animal Free Organoids (TRAFO) (2023 - 2025)

Together with his project group, Paul Kouwer has received a Create2Solve grant from ZonMw for his project ‘Transition to Animal-Free Organoids’(TRAFO). With this 100,00 euro grant, researchers from Radboud University will collaborate with HUB Organoids to develop an animal-free method to grow mini organs (organoids). Read more in the press release.

Orgatrix (2024 - 2026)

Paul Kouwer, in collaboration with Marleen Ansems from Radboudumc, has secured a grant from the Dutch Cancer Society (KWF) for their research project Orgatrix. The grant, amounting to 235,000 euros, will support the team's investigation into the optimal conditions for the in vitro cultivation of mini head and neck tumors, also known as tumor organoids. Read more in the press release.

Contact information