This study designed a novel multifunctional Janus structure dressing (DNCD dressing) composed of spacer fabric, agar/sodium alginate/calcium ion dual-network aerogel, methylene blue, and AgNO 3 -added thermoplastic polyurethane nanofiber membrane. The unidirectional liquid transport and absorbency tests prove that the DNCD dressing can unidirectionally transport liquids within just two seconds and possesses a liquid absorption ratio of 875.3 %. The unique open structure formed by the spacer fabric and liquid transport channels provides excellent air permeability as well as a suitable water vapor transmission rate, reaching 584.96 mm/s, 10.3 L/min, and 1104.82 g/m 2 /24 h, respectively. The exceptional compressive strength (216.78 kPa) and compressive modulus (515.23 kPa) of the dressing can provide protection for the wound. Antibacterial tests demonstrate that the silver ion-added DNCD dressing can eradicate >99 % of Escherichia coli and Staphylococcus aureus , while the added methylene blue can effectively monitor the survival status of bacteria. The low BCI value and the hemolysis ratio of <5 % indicate that the DNCD dressing has a certain hemostatic ability and does not cause hemolysis. The results of cytotoxicity tests and full-thickness skin defect models show that the DNCD dressing has good cytocompatibility and the potential to promote wound healing.
Shuhua Tu,Chenxu Zhu,Lingyun Zhang,Haitao Wang,Qiangguo Du
A novel approach for the preparation of interconnected macroporous polymers with a controllable pore structure was reported. The method was based on the polymerization of water-in-oil Pickering high internal phase emulsion (HIPE) stabilized by polystyrene (PS)/silica composite particles. The composite Pickering stabilizers were facilely obtained by mixing positively charged PS microspheres and negatively charged silica nanoparticles, and their amphiphilicity could be delicately tailored by varying the ratio of PS and silica. The droplet size of Pickering HIPEs was characterized using an optical microscope. The pore structure of polymer foams was observed using a scanning electron microscope. The interconnectivity of macroporous polymers was evaluated upon their gas permeability, which was greatly improved after etching PS microspheres included in the Pickering stabilizers with tetrahydrofuran. As a result, fine tailoring of the pore structure of polymer foams could be realized by simply tuning the ratio of PS to silica particles in the composite stabilizer.
Hui-Ling Peng,Tu Qian,Tong Xian,Chunsheng Jiang,Yunbai Qin,Quanfu Li,Shuxiang Song
Epidermal electronics have attracted extensive attention owing to their potential in personal healthcare and human–machine interactions (HMIs). However, their low conductivity and poor ability to conform to the human skin impede their practical application. Herein, a multifunctional flexible dry epidermal electrode for biopotential recording and muscle thermotherapy was developed based a conductive polymer (poly(3,4-ethylenedioxythiophene) doped with polystyrene sulfonic acid (PEDOT:PSS)). PEDOT:PSS was modified using poly(vinyl alcohol) (PVA) with hydrophobic groups. The electrode is able to self-adhere to human skin through a hydrophobic interaction with the skin. Moreover, the hydrophilic groups can absorb the humidity under the skin and move it by the hydrophobic groups, which allows the electrode exhibits good gas-permeability. The ultrathin electrode conforms well to the topography of the human skin and, thus, can form a stable and intimate interface with it, resulting in a low electrode–skin contact impedance that allows the recording of biopotentials with high quality. Moreover, the electrode exhibits rapid Joule heating performance at a low voltage (up to 53.8 °C in 12 s at 1.5 V), which is suitable for the electrothermal therapy of muscle. On-body measurements confirm that our electrode could detect muscle fatigue via electromyography (EMG) and perform electrothermal therapy to relieve muscle fatigue. This study offers an efficient method for developing all-in-one wearable flexible epidermal electrode for biopotential recording and muscle theranostics.
危险品化学品经营许可证（带存储）