It is highly desired yet challenging to fabricate biocompatible injectable self-healing hydrogels with anti-bacterial adhesion properties for complex wounds that can autonomously adapt to different shapes and depths and can promote angiogenesis and dermal collagen synthesis for rapid wound healing. Herein, an injectable zwitterionic hydrogel with excellent self-healing property, good cytocompatibility, and antibacterial adhesion was developed from a thermoresponsive ABA triblock copolymer poly[(N-isopropyl acrylamide)-co-(butyl acrylate)-co-(sulfobetaine methacrylate)]-b-poly(ethylene glycol)-b-poly[(N-isopropyl acrylamide)-co-(butyl acrylate)-co-(sulfobetaine methacrylate)] (PZOPZ). The prepared PZOPZ hydrogel exhibits a distinct thermal-induced sol−gel transition around physiological temperature and could be easily applied in a sol state and in situ gelled to adapt complex wounds of different shapes and depths for complete coverage. Meanwhile, the hydrogel possesses a rapid selfhealing ability and can recover autonomously from damage to maintain structural and functional integrity. In addition, the CCK-8 and 2D/3D cell culture experiments revealed that the PZOPZ hydrogel dressing shows low cytotoxicity to L929 cells and can effectively prevent the adhesion of Staphylococcus aureus and Escherichia coli. In vivo investigations verified that the PZOPZ hydrogel could increase angiogenesis and dermal collagen synthesis and shorten the transition from the inflammatory to the proliferative stage, thereby providing more favorable conditions for faster wound healing. Overall, this work provides a promising strategy to develop injectable zwitterionic hydrogel dressings with multiple functions for clinic wound management.

Cation-π interaction is considered one of the strongest non-covalent interactions in aqueous solutions, which endows natural biomolecules (e.g., proteins) with robust wet adhesion and cohesion in humid/underwater environments. However, it still remains a challenge to construct synthetic functional materials (e.g., self-healing hydrogels) by rationally adopting the cation-π interactions. Herein, we present a facile and novel strategy to fabricate injectable selfhealing synthetic hydrogel from the self-assembly of a thermo-responsive ABA triblock copolymer via cation-π interactions, which is composed of a modified poly (Nisopropylacrylamide) (PNIPAM) incorporated with cationic and aromatic components as A block and a hydrophilic poly (ethylene oxide) (PEO) as B block. Upon thermally induced gelation, the cationic and aromatic components will be closely and densely packed into nanoconfined micelles to provide reversible and strong cation-π interactions, thereby endowing the resulting hydrogel with an eye-catching self-healing performance upon hydrogel damage. The hydrogel also exhibits an excellent thermo-responsive reversible sol-gel transition and a clear shear-thinning property that offers the developed hydrogel with the injectability. This work

Developing a self-healing hydrogel wound dressing with intrinsic antibacterial and on-demand dissociable properties is highly desired yet challenging in clinician applications to enhance angiogenesis and collagen growth for rapid wound healing. Herein, we present a thermoresponsive self-healing hydrogel dressing with intrinsic antimicrobial property based on a poly(Nisopropylacrylamide)-derived ABA triblock copolymer (TNOTN) and an aldehyde β-cyclodextrin (ACD) for rapid healing of fullthickness infected wounds. The prepared TNOTN−ACD hydrogel exhibits excellent thermal responsiveness with a well-defined thermal-induced sol−gel transition, allowing in situ gelling and on-demand removal of wound dressing via temperature switch. Meanwhile, the dynamic Schiff base bonds formed between TNOTN and ACD endow the hydrogel with excellent self-healing properties, which can maintain structural integrity for constant and effective antibacterial performance. Meanwhile, TNOTN−ACD hydrogels have good antibacterial properties against both S. aureus and E. coli, as well as good biocompatibility and hemocompatibility. More importantly, in vivo spatial metabolomics revealed that the TNOTN−ACD hydrogel dressing could accelerate angiogenesis and collagen deposition via the arginine-related biosynthesis pathways, thereby effectively promoting wound closure in a full-thickness bacteria-infected skin defect.

Acetalization has been commonly adopted to realize the improvement on the water resistance and mechanical properties of poly(vinyl alcohol) (PVA) composite fibers. However, acetalized PVA fibers only have a very low concentration of hydroxyl groups on the surface and thus have poor dyeing performance. In this case, hydroxyl-rich nanocellulose (NC) offers a fascinating solution for improving the dyeing properties of PVA fibers. Herein, we developed NC/PVA composite fibers by wet spinning the aqueous mixture of NC and PVA followed with acetalization treatment. Compared with pure PVA fibers, NC/PVA composite fibers had a significant improvement of 36% and 53% in terms of tensile strength and elongation at break when the NC content was 10 wt%, respectively. More importantly, when the NC content reached 20 wt%, the K/S value of the composite fiber was approximately threefold greater in comparison to that of the PVA fiber, indicating that the dyeing performance of NC-modified composite fibers was greatly improved. This work provides a simple and easy method to possess PVA fibers with excellent dyeing properties and mechanical properties, demonstrating the potential to realize the application of PVA fibers in more practical scenarios.

Biomass-based flocculants have been widely studied and applied to wastewater treatment due to their environmental friendliness. However, these flocculants tend to generate flocs with small size and lead to difficult solid-liquid separation after the flocculation. The key to solving the floc size problem is enhancing intermolecular or intramolecular interaction forces by changing the molecular structure and functional groups of flocculants. Herein, we developed a mussel-inspired cationic biomass flocculant by functionalizing chitosan (CS) with cation component acryloyloxyethyltrimethyl ammonium chloride (DAC) and mussel-inspired monomer N-2-(3, 4-dihydroxyphenethyl) acrylamide (DAA) through free radical polymerization. The prepared flocculant could provide multiple interaction forces such as electrostatic interaction, cation-π interaction, π −π stacking, and hydrogen bonding to pollutants. As a result, the spent CS-g-p (DAC-co-DAA) flocculant generate dye-containing flocs with dramatically increased size when compared with its counterpart CS-g-pDAC without catechol groups and are capable to realize more than 95% removal efficiency towards organic dyes such as MB and CR over a broad pH range from 3 to 9. This study provides some insights in how to apply this mussel-inspired strategy to develop environmentally friendly biomass-derived flocculants with floc enlarging capacity to treat organic wastewaters in wide pH range.