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 (HO), a major reactive oxygen species (ROS), the injectable hydrogel could be used as a HO/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 HO 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.