In situ hydrogels have attracted considerable attention in tissue engineering because of their minimal invasiveness and ability to match the irregular tissue defects. However, hydrous physiological environments and the high level of moisture in hydrogels severely hamper binding to the target tissue and easily cause wound infection, thereby limiting the effectiveness in wound care management. Thus, forming an intimate assembly of the hydrogel to the tissue and preventing wound infecting still remains a significant challenge. In this study, inspired by mussel adhesive protein, a biomimetic dopamine‐modified ε‐poly‐l‐lysine‐polyethylene glycol‐based hydrogel (PPD hydrogel) wound dressing is developed in situ using horseradish peroxidase cross‐linking. The biomimetic catechol–Lys residue distribution in PPD polymer provides a catechol–Lys cooperation effect, which endows the PPD hydrogels with superior wet tissue adhesion properties. It is demonstrated that the PPD hydrogel can facilely and intimately integrate with biological tissue and exhibits superior capacity of in vivo hemostatic and accelerated wound repair. In addition, the hydrogels exhibit outstanding anti‐infection property because of the inherent antibacterial ability of ε‐poly‐l‐lysine. These findings shed new light on the development of mussel‐inspired tissue‐anchored and antibacterial hydrogel materials serving as wound dressings.

No abstract

Novel sunscreen products based on bioadhesive/gel systems that can prevent the skin penetration behaviors of UV filters have attracted increasing attention in recent years. However, integration is very difficult to achieve and control on the wet surface of the skin under sweaty/dynamic physiological conditions, resulting in functional failure. Herein, we demonstrated the fabrication of a novel dual-network hydrogel sunscreen (DNHS) based on poly-γ-glutamic acid (γ-PGA) and tannic acid (TA), which demonstrated prominent UV protection properties across broad UVA and UVB regions (360–275 nm). Due to a three-dimensional network microstructure and a highly hydrated nature that mimics the extracellular matrix of natural skin, DNHS can perfectly match the skin surface without irritation and sensitization. In addition, the intermolecular hydrogen bond interactions of γ-PGA and TA provide an important driving force for coacervation, which endows the DNHS with remarkable self-recovery properties (within 60 s). Moreover, due to the multiple interfacial interactions between γ-PGA/TA and the protein-rich skin tissue surfaces, DNHS simultaneously possesses excellent skin-integration and water-resistance capacities, and it can be readily removed on demand. Our results highlight the potential of the DNHS to be used in next-generation sunscreens by providing long-term and stable UV protection functions even under sweaty/dynamic physiological conditions.

No abstract