Fabrication of versatile dynamic hyaluronic acid-based hydrogels

In this study, an injectable and self-healing hydrogel based on the boronic ester dynamic covalent bond between phenylboronic acid modified hyaluronic acid (HA-PBA) and the commercially available poly (vinyl alcohol) (PVA) is prepared and should have multi-functions for biomedical applications. The hydrogels were rapidly formed under mild conditions, and the rheological properties and in vitro degradation were systematically characterized. The HA-based hydrogels possessed good injectability and self-healing properties because of the dynamic bond. Moreover, due to the sensitivity of boronic ester to the biologically relevant concentration of hydrogen peroxide (H₂O₂), a major reactive oxygen species (ROS), the injectable hydrogel could be used as a H₂O₂/ROS responsive drug delivery system. The hydrogels supported good viability of encapsulated neural progenitor cells (NPC) and protected NPC from ROS induced damage in vitro when H₂O₂ was present in the media. The dynamic hydrogels were further applied as bio-inks for 3D printing/bioprinting. Overall, this facilely prepared dynamic hydrogel based on HA-PBA and PVA may have many potential biomedical applications, including drug delivery, 3D culture of cells, and 3D bioprinting.