In Situ Fabrication of Robust Polyphenolic Hydrogels for Skin Protection and Repair

Robust and multifunctional polyphenolic hydrogels have been well acknowledged as promising biomaterial candidates due to their various fascinating properties in regulating cell biology. However, the construction of these hydrogels commonly needs multistep fabrication and a sophisticated gelation process. The typical phenol-aldehyde condensation is a facial and in situ reaction for industrial resin construction; however, its application in hydrogel fabrication is seldom reported. In this study, we reported the feasibility and modularity of this strategy for in situ fabricating various kinds of robust and multifunctional natural polyphenolic hydrogels using natural polyphenol (extracts) and formaldehyde. The physicochemical characterization results demonstrated that the chemical structure (e.g., phenolic hydroxyl groups) of polyphenol molecules could be well maintained after the gelation process, allowing as-prepared hydrogels to inherit the merits of polyphenol molecules, such as good UV shielding, radical scavenging, antibacterial properties, and so forth, as demonstrated by in vitro data. The in vitro and in vivo cellular and animal results further confirmed that the as-prepared hydrogels were able to perform a skin protection and repair role, as demonstrated in UV protection and wound healing models. Collectively, this strategy could allow natural polyphenols as both structural and functional synthons toward more types of robust hydrogels for a wide range of biomedical applications.

Automated summary

This study reports the in situ fabrication of various types of robust and multifunctional natural polyphenolic hydrogels using natural polyphenol (extracts) and formaldehyde. The results show that the chemical structure of polyphenol molecules can be well maintained after the gelation process, allowing the hydrogels to inherit the merits of polyphenol molecules, such as UV shielding, radical scavenging, and antibacterial properties. In vitro and in vivo experiments further confirm that the hydrogels can perform a skin protection and repair role, making them suitable for biomedical applications.