Hydrogels are a popular class of biomaterials consisting of three-dimensional networks composed of crosslinked water-soluble synthetic and natural polymers. The intriguing ability of hydrogels to contain large amounts of water makes them perfect to mimic the natural extra-cellular matrix (ECM) and therefore they are currently used in multiple biomedical applications.
The final shape of the hydrogel is highly important for many applications; however hydrogels are notoriously hard to process. Processing possibilities include film casting, 3D-printing, electrospinning, electro-spraying and 2-photon polymerization. Current hydrogel precursors can only be UV-crosslinked in solution or in the molten state, which is highly challenging. Hence, there is a clear need for hydrogels that are easy to process, leading to accurate and reproducible final shapes.
Researchers at Ghent University in collaboration with Allnex, have developed a series of novel urethane-based hydrogel precursors. These precursors have the unique properties of being able to be crosslinked (UV-cured) in the solid state (in the absence of solvent), allowing to accurately pre-shape the material via solidification trough several processing techniques, prior to hydrogel formation. Moreover, highly biocompatible materials are obtained because the covalent crosslinking of the precursors can occur without addition of photo-initiators.
Depending on the application, flexible crosslinked networks can be obtained with tunable properties such as, hydrophilic/hydrophobic balance, thermal- and mechanical properties, crosslink densities, mesh size, porosity etc. The required properties greatly depend on the envisaged application and the processing method.
Our versatile proprietary hydrogel precursors can be specifically used in multiple biomedical applications, including contact lenses, wound dressings, tissue engineering materials, delivery systems for bioactive components or as biocompatible coating on implants or other materials. Hydrogel development might primary feed into a series of biomedical soft tissue applications with challenging processing constraints.
The novel urethane based precursors can be easily processed via moulding, 3D-printing, electrospinning, or electrospraying, prior to cross-linking. Microstructures can be created in the solid state using 2-photon-polymerization.
The precursors and hydrogels were characterized and evaluated in in vitro biocompatibility assays.