From Short Circuit to Completed Circuit: Conductive Hydrogel Facilitating Oral Wound Healing.

The primary challenges posed by oral mucosal diseases are their high incidence and the difficulty in managing symptoms. Inspired by the ability of bioelectricity to activate cells, accelerate metabolism, and enhance immunity, a conductive polyacrylamide/sodium alginate crosslinked hydrogel composite containing reduced graphene oxide (PAA-SA@rGO) is developed. This composite possesses antibacterial, anti-inflammatory, and antioxidant properties, serving as a bridge to turn the "short circuit" of the injured site into a "completed circuit," thereby prompting fibroblasts in proximity to the wound site to secrete growth factors and expedite tissue regeneration. Simultaneously, the PAA-SA@rGO hydrogel effectively seals wounds to form a barrier, exhibits antibacterial and anti-inflammatory properties, and prevents foreign bacterial invasion. As the electric field of the wound is rebuilt and repaired by the PAA-SA@rGO hydrogel, a 5 × 5 mm2 wound in the full-thickness buccal mucosa of rats can be expeditiously mended within mere 7 days. The theoretical calculations indicate that the PAA-SA@rGO hydrogel can aggregate and express SOX2, PITX1, and PITX2 at the wound site, which has a promoting effect on rapid wound healing. Importantly, this PAA-SA@rGO hydrogel has a fast curative effect and only needs to be applied for the first three days, which significantly improves patient satisfaction during treatment.

A Strategy Inspired by the Cicada Shedding Its Skin for Synthesizing the Natural Material NaFe3 S5 ·2H2 O.

Sulfide minerals hold significant importance in both fundamental science and industrial advancement. However, certain natural sulfide minerals, such as NaFe3 S5 ·2H2 O (NFS), pose great challenges for exploitation and synthesis due to their high susceptibility to oxidation. To date, no successful precedent exists for synthesizing NFS. Here, a novel approach to synthesizing low-cost and pollution-free NFS with high stability using the high-pressure hydrothermal method based solely on knowledge of its chemical formula is presented. Moreover, an innovative strategy inspired by the cicada's molting process to develop unstable natural materials is proposed. The mechanical, thermal, optical, electrochemical, and magnetic properties of the NFS are thoroughly investigated. The storage of lithium, sodium, and potassium ions is primarily concentrated in the gap between (0 0 1) crystal planes. Additionally, as a catalyst for hydrogen evolution reaction (HER) at 10 mA cm-2 , micron-sized NFS exhibits an excellent overpotential of 6.5 mV at 90 °C, surpassing those of reported HER catalysts of similar size. This research bridges the gap in the sulfide mineral family, overcomes limitations of the high-pressure hydrothermal method, and paves the way for future synthesis of natural minerals, lunar minerals, and Martian minerals.

Twining Poly(polyoxometalate) Chains into Nanoropes.

Organic polymers and inorganic clusters belong to two different disciplines and have completely different properties and structures. When a cluster is attached to the backbone of a polymer as a pendant, the resultant hybrid polymers (polyclusters) exhibit unique behaviours totally different from those of conventional polymers owing to the nanoscale size of the cluster and its particular interactions. Herein, the aggregation of a poly(polyoxometalate)-a polynorbornene backbone with inorganic polyoxometalate cluster pendants-upon addition of a non-solvent to its dilute solution is reported. A three-dimensional network of tangled and snake-like nanothreads was observed. Direct visualisation of individual nanoscale clusters enabled identification of single chains within the nanothreads. These observations suggest that during the process of aggregation, the hybrid polymer forms curved or extended chains as a consequence of an armouring effect in which the collapsed cluster pendants wrap around the backbone. The collapse occurs because they become less soluble in the solvent/non-solvent mixture. The extended chains then become entwined and form nanoropes consisting of multiple chains wound around each other. This study provides a deeper understanding of the nature of polyclusters and should also prove useful for their future development and application.

Preparation of AgCl Nanocubes and Their Application as Efficient Photoinitiators in the Polymerization of N-Isopropylacrylamide.

Uniform AgCl nanocubes with an average size of about 360 nm have been synthesized. Under UV illumination, a layer of silver nanoparticles with surface plasmon resonance was produced and covered the surface of AgCl particles in a short time, and the Ag/AgCl particles remained quite stable as shown in XRD patterns. The as-synthesized AgCl particles were tried for the first time as photoinitiator to polymerize N-isopropylacrylamide under UV-irradiation, and a high efficiency and conversion rate were realized. The structure of the polymers was studied by FTIR spectrophotometer. The results of turbidimetric method showed that the polymers were temperature sensitive and their lower critical solution temperature was about 33 °C. The effects of photoinitiators concentration, monomers concentration, and irradiation time on the polymer yield were investigated. The reaction mechanism was discussed by using salicylic acid as scavengers of hydroxyl radicals and conducting the reaction under oxygen atmosphere, respectively. The results proved that hydroxyl radicals were essential to chain initiation.

A controlled thiol-initiated surface polymerization strategy for the preparation of hydrophilic polymer stationary phases.

A controlled thiol-initiated surface polymerization strategy has been successfully developed and employed to prepare hydrophilic polymer stationary phases, which exhibited excellent chromatographic performance and protein non-fouling properties.

Incorporation of Polyoxometalates into Polymers to Create Linear Poly(polyoxometalate)s with Catalytic Function.

Organic polymers have been found widespread commercial applications due to their easy processing and attractive mechanical properties. Concurrently, inorganic polyoxometalates (POMs), a class of metal-oxygen anionic and nanosized clusters of early transition metals, have a wide range of attractive functions and are used in industrial catalysis. In this communication, we report a new approach to creating the first linear poly(polyoxometalate)s that combine the advantages of polymers and POM clusters. In the experiment, a POM-containing norbornene monomer was first synthesized by linking a Wells-Dawson-type POM with a norbornene derivative. The monomer was polymerized in the presence of a Grubbs catalyst under mild conditions with yields nearly 100% in a living and controllable manner. The resulting poly(polyoxometalate)s have controllable molecular weights and a well-defined hybrid structure of an organic polynorbornene backbone with large pendant groups of the nanosized POM clusters. Thus, they form good films and have a good catalytic performance. Our findings not only pave the way for incorporating the POM clusters into polymers with well-defined structures and high molecular weights, but also offer a competitive strategy for developing more novel catalytic systems by introducing the poly(polyoxometalate)s.

A photoconductive charge-transfer crystal with mixed-stacking donor-acceptor heterojunctions within the lattice.

A pyrene derivative as the donor and a butyl-viologen as the acceptor were used to construct a novel charge-transfer cocrystal consisting of mixed-stacking structure and having switchable photoconductivity stemming from the donor-acceptor heterojunctions within the lattice.