Yukun Yan
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3 records found
1
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.
In recent years, various functional fabrics capable of responding to multistimuli have been widely recognized as promising wearable devices. However, the obtained composite functional fabrics have only been applied in a few scenarios, rendering the achievement of multifunctional wearable application scenarios a difficult goal. Therefore, there is an urgent need to expand the diversity of wearable applications for functional fabrics. Herein, we design hydrogel composite fabrics capable of responding to multiple stimuli, including vibration, temperature, strain, and pressure, to enable wearable multiapplication scenarios. The hydrogel composite fabrics, based on nylon fabrics (NFs), are fabricated with polyacrylamide (PAM)-poly(vinyl alcohol) (PVA)-sodium alginate (SA)-reduced graphene oxide (rGO)/NFs (PAM-PVA-SA-rGO/NFs). The PAM-PVA-SA-rGO/NFs exhibit a higher elastic stiffness coefficient (2.79 N cm-1) than the blank NFs (1.76 N cm-1), good temperature sensitivity in the range of 30-80 °C, and excellent detecting ability for urine presence with a threshold of unit area of 2.55 × 10-3 mL cm-2. The PAM-PVA-SA-rGO/NFs can not only respond to multiple stimuli but also be integrated into clothing for wearable multiapplication scenarios, such as detecting human speaking and breathing, intelligent sleeves, and diaper alarms. Additionally, the mechanisms of the above phenomena are revealed. These results indicate that the PAM-PVA-SA-rGO/NFs will provide inspiration for the development of intelligence systems, feedback devices, soft robotics, wearable devices, etc.
Sulfide minerals hold significant importance in both fundamental science and industrial advancement. However, certain natural sulfide minerals, such as NaFe3S5·2H2O (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.