Hyaluronic Acid Based Materials for Scaffolding via Two-Photon Polymerization

Hydrogels are able to mimic the basic three-dimensional (3D) biological, chemical, and mechanical properties of native tissues. Since hyaluronic acid (HA) is a chief component of human extracellular matrix (ECM), it represents an extremely attractive starting material for the fabrication of scaffolds for tissue engineering. Due to poor mechanical properties of hydrogels, structure fabrication of this material class remains a major challenge. Two-photon polymerization (2PP) is a promising technique for biomedical applications, which allows the fabrication of complex 3D microstructures by moving the laser focus in the volume of a photosensitive material. Chemical modification of hyaluronan allows application of the 2PP technique to this natural material and, thus, precise fabrication of 3D hydrogel constructs. To create materials with tailor-made mechanochemical properties, HA was combined and covalently cross-linked with poly(ethylene glycol) diacrylate (PEGDA) in situ. 2PP was applied for the fabrication of well elaborated 3D HA and HA–PEGDA microstructures. For enhanced biological adaption, HA was functionalized with human epidermal growth factor.