Humans are threatened by bacteria and other microorganisms, resulting in countless pathogen-related infections and illnesses. Accumulation of reactive oxygen species (ROS) in infected wounds activates strong inflammatory responses. The overuse of antibiotics has led to increasing bacterial resistance. Therefore, effective ROS scavenging and bactericidal capacity are essential and the advanced development of collaborative therapeutic techniques to combat bacterial infections is needed. Here, this work developes an MXene@polydopamine-cryptotanshinone (MXene@PDA-CPT) antibacterial nanosystem with excellent reactive oxygen and nitrogen species scavenging ability, which effectively inactivates drug-resistant bacteria and biofilms, thereby promoting wound healing. In this system, the adhesion of polydopamine nanoparticles to MXene produced a photothermal synergistic effect and free radical scavenging activity, presenting a promising antibacterial and anti-inflammatory strategy. This nanosystem causes fatal damage to bacterial membranes. The loading of cryptotanshinone further expanded the advantages of the system, causing a stronger bacterial killing effect and inflammation mitigatory effect with desired biosafety and biocompatibility. In addition, combining nanomaterials and active ingredients of traditional Chinese medicine, this work provides a new rationale for the future development of wound dressings, which contributes to eliminating bacterial resistance, delaying disease deterioration, and alleviating the pain of patients.
Fan Zhang,Yi-liang Zou,Rui Lou,Jing-hui Yang,De-xiang Sun,Nan Zhang,Yong Wang
Environment-friendly dielectric materials with high energy density and charge–discharge efficiency are urgently required in dielectric capacitors. Here, we prepared the cellulose acetate (CA)-based sandwich-structured composite films by solution casting technique. To reduce the conductivity of MXene and upgrade the compatibility between filler and matrix, MXene was modified by polydopamine (PDA) to obtain MXene@PDA (M@P) hybrid filler, and then it was added into CA matrix to manufacture CA/M@P as the middle layer to significantly improve dielectric constant, while poly(vinylidene fluoride) (PVDF) with excellent insulation property was designed as the outer layers. The results indicate that the strong hydrogen bonding interaction between layers is conducive to the dense internal structure of the composite films, and a prominently strengthened discharged energy density (12.53 J/cm 3 ) and efficiency (72.12%) at 625 MV/m are reached in composite film containing 1 wt% M@P, with ultrahigh stability during the 10 6 consecutive charge-discharge measurements. Furthermore, the composite films also exhibit good mechanical properties. This work suggests the practicability of CA in substituting petroleum-based polymers in the dielectric capacitors.
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