Traditional wound dressings mainly participate in the passive healing processes and are rarely engaged in active wound healing by stimulating skin cell behaviors. Electrical stimulation (ES) has been known to regulate skin cell behaviors. Herein, a series of multifunctional hydrogels based on regenerated bacterial cellulose (rBC) and MXene (Ti 3 C 2 T x) are first developed that can electrically modulate cell behaviors for active skin wound healing under external ES. The composite hydrogel with 2 wt% MXene (rBC/MXene-2%) exhibits the highest electrical conductivity and the best biocompatibility. Meanwhile, the rBC/MXene-2% hydrogel presents desired mechanical properties, favorable flexibility, good biodegradability, and high water-uptake capacity. An in vivo study using a rat full-thickness defect model reveals that this rBC/MXene hydrogel exhibits a better therapeutic effect than the commercial Tegaderm film. More importantly, in vitro and in vivo data demonstrate that coupling with ES, the hydrogel can significantly enhance the proliferation activity of NIH3T3 cells and accelerate the wound healing process, as compared to non-ES controls. This study suggests that the biodegradable and electroactive rBC/MXene hydrogel is an appealing candidate as a wound dressing for skin wound healing, while also providing an effective synergistic therapeutic strategy for accelerating wound repair process through coupling ES with the hydrogel dressing.

Bacterial-associated wound infection and antibiotic resistance have posed a major burden on patients and health care systems. Thus, developing a novel multifunctional antibiotic-free wound dressing that cannot only effectively prevent wound infection, but also facilitate wound healing is urgently desired. Herein, a series of multifunctional nanocomposite hydrogels with remarkable antibacterial, antioxidant, and anti-inflammatory capabilities, based on bacterial cellulose (BC), gelatin (Gel), and selenium nanoparticles (SeNPs), are constructed for wound healing application. The BC/Gel/SeNPs nanocomposite hydrogels exhibit excellent mechanical properties, good swelling ability, flexibility and biodegradability, and favorable biocompatibility, as well as slow and sustainable release profiles of SeNPs. The decoration of SeNPs endows the hydrogels with superior antioxidant and anti-inflammatory capability, and outstanding antibacterial activity against both common bacteria (E. coli and S. aureus) and their multidrug-resistant counterparts. Furthermore, the BC/Gel/SeNPs hydrogels show an excellent skin wound healing performance in a rat full-thickness defect model, as evidenced by the significantly reduced inflammation, and the notably enhanced wound closure, granulation tissue formation, collagen deposition, angiogenesis, and fibroblast activation and differentiation. This study suggests that the developed multifunctional BC/Gel/SeNPs nanocomposite hydrogel holds a great promise as a wound dressing for preventing wound infection and accelerating skin regeneration in clinic.

Carbonaceous and polymer materials are extensively employed as conductor and container to encapsulate sulfur particles and limit polysulfide dissolution. Even so, high-power performance is still far from satisfaction due to the expansion and collapse of the electrode materials during thousands of charge-discharge process. Herein, it is found that colloidal carbon sphere with high elastic coefficient can be utilized as a framework to load sulfur, which can trap soluble polysulfides species in the pores within the sphere and efficaciously improve the electronic conductivity of the cathode. After modified by polyaniline (PAN) through in situ polymerization, PAN-assisted S/C nanosphere (PSCs-73, with 73 wt % sulfur) effectively minimize polysulfide diffusion, enhance the electron transfer rate and overcome the problem of volume expansion. The fabricated PSCs-73 cell shows outstanding long high-power cycling capability over 2500 charge/discharge cycles with a capacity decay of 0.01% per cycle at 5 C. Substantially, this composite can drive 2.28 W white indicators of LED robustly after minutes of charging by three lithium batteries in series, showing a promising potential application in the future.

Carbon-supported Pt nanoparticles are used as catalysts for a variety of reactions including the oxygen reduction reaction (ORR) key to proton-exchange membrane fuel cells, but their catalytic performance has long been plagued by detachment and sintering. Here we report the in situ growth of sub-2 nm Pt particles on a commercial carbon support via the galvanic reaction between a Pt(II) precursor and a uniform film of amorphous Se predeposited on the support. The residual Se could serve as a linker to strongly anchor the Pt nanoparticles to the carbon surface, leading to a catalytic system with extraordinary activity and durability toward ORR. Even after 20 000 cycles of accelerated durability test, the sub-2 nm Pt particles were still dispersed well on the carbon support and maintained a mass activity more than three-times as high as the pristine value of a commercial Pt/C catalyst.

Single-atom and double-atom catalysts have emerged as new frontiers in many fields due to their high atom-utilization efficiency, excellent catalytic properties and good durability. In this decade, Fe-based atomic catalysts...

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An integrated PGCNF/S aerogel with a “network” structure has effectively restricted the shuttling of polysulfides and exhibited promising lithium ion storage capability.