Hydrogel platform uses vitamin B2 and blue light to simplify living tissue models

Researchers at Tampere University have developed a hydrogel platform that uses gallic acid-modified biopolymers, riboflavin (vitamin B2), and blue light to create customizable biomaterials for tissue engineering and disease modeling. The system crosslinks rapidly under gentle, cell-friendly conditions and simultaneously binds a wide variety of biological molecules — including proteins, DNA, and RNA — without requiring those molecules to be chemically modified beforehand.

Conventional hydrogel methods often involve multiple chemical modification steps, specialized reagents, or conditions that can limit biological functionality and complicate customization. The new platform addresses these limitations by relying on gallic acid, a naturally occurring antioxidant found in plants, fruits, and tea leaves, and riboflavin, a vitamin already present in biological systems. In some cases, hydrogel formation occurs using standard cell culture media alone, without a separate photoinitiator.

Lead author Austin Donnelly Evans, a doctoral researcher at Tampere University, said the goal was to create a simple, flexible platform that preserves the bioactivity of incorporated molecules. The researchers demonstrated that the Wnt3A signaling protein remained biologically active after being embedded in the hydrogel and continued to influence cell behavior. The hydrogels also supported high cell viability and enabled three-dimensional cell growth that more closely resembles living tissues.

The platform's physical properties can be tailored, and specific biological components can be selected to create tissue-specific environments. The resulting materials are described as dynamic, partially self-healing, viscoelastic, and flexible — behaving more like natural tissues. Hydrogels constructed from different components supported differential growth of colorectal cancer cell models in 3D tumoroids, which more closely mimic human tumors.

Professor Oommen P. Oommen, who led the study, noted that the approach functions as a modular molecular "glue," allowing diverse biological components to be combined into tailor-made materials with fewer components and simpler chemistry. Professor Vesa Hytönen added that lowering technical barriers and increasing flexibility could help researchers build more realistic models of human tissues and diseases.

The researchers envision the technology accelerating the development of advanced 3D cell culture systems, personalized tissue models, biofabrication technologies, drug testing platforms, and future hydrogel-based therapies. The work was published in Cell Reports Physical Science.