IMDEA Materials Institute has developed mechanically tunable hydrogel membranes that closely mimic the mechanical environment of human skin while remaining highly biocompatible, representing an improved platform for skin tissue engineering and regenerative medicine.

The research, published in the International Journal of Biological Macromolecules, demonstrates how seafood industry by-products such as chitosan extracted from shrimp shells, and gelatin obtained from cold-water fish skin, can be transformed into high-value biomedical materials.

This offers a sustainable alternative to conventional sources while reducing waste.

Chitosan is already known for its biodegradability, antibacterial properties and structural similarity to components of the human extracellular matrix. Fish gelatin, meanwhile, contains biological signals that encourage cells to attach, grow and regenerate tissue.

By combining these two renewable materials with a biocompatible crosslinking agent, the researchers produced transparent hydrogel membranes whose physical properties can be precisely tuned to suit different skin-related applications.

Unlike many existing biomaterials, the membranes are more than 85% transparent, allowing researchers and clinicians to observe cells and tissue development directly without disturbing the culture. At the same time, their stiffness can be adjusted across a wide range, enabling the material to better reproduce the mechanical cues that regulate skin cell behaviour.

The team systematically varied the composition of the membranes to investigate how their physical properties influenced different types of skin cells. Laboratory testing confirmed excellent cytocompatibility, with cell viability exceeding 80% across mouse fibroblasts, human epidermal keratinocytes and primary human dermal fibroblasts.

One formulation, containing 2% chitosan, 2% fish gelatin and 2% crosslinker, proved particularly effective. With a stiffness comparable to native skin tissue, it promoted the attachment, spreading and long-term growth of human skin cells while supporting collagen deposition, an essential component of healthy skin regeneration.

“Our goal was to develop a sustainable biomaterial whose properties could be precisely tailored to recreate the environment that skin cells experience in the body,” explains Dr. Jennifer Patterson, head of the Biomaterials and Regenerative Medicine Group at IMDEA Materials and one of the authors behind the study.

“By controlling the membrane’s composition, we can influence how cells interact with it, creating a versatile platform for skin tissue engineering, wound-healing research and laboratory skin models.”

Beyond its biomedical performance, the work also contributes to the growing circular bioeconomy by demonstrating how waste streams from the seafood industry can be converted into advanced healthcare materials.

The researchers believe the platform could eventually support applications ranging from in vitro skin models for drug testing to regenerative therapies for wound healing.

Alongside Dr. Patterson, the publication was authored by IMDEA Materials’ Shuanglan Du, Dr. Pedro Navarrete Segado from the University of Jaén (formerly IMDEA Materials), and Miguel Rey Marfil (former TFG student at IMDEA Materials from Universidad Europea de Madrid).