RESUMEN

Decorating surfaces with wetting gradients or topological structures is a prevailing strategy to control uni-directional spreading without energy input. However, current methods, limited by fixed design, cannot achieve multi-directional control of liquids, posing challenges to practical applications. Here, a structured surface composed of arrayed three-dimensional asymmetric fang-structured units is reported that enable in situ control of customized multi-directional spreading for different surface tension liquids, exhibiting five novel modes. This is attributed to bottom-up distributed multi-curvature features of surface units, which create varied Laplace pressure gradients to guide the spreading of different-wettability liquids along specific directions. The surface's capability to respond to liquid properties for multimodal control leads to innovative functions that are absent in conventional structured surfaces. Selective multi-path circuits can be constructed by taking advantage of rich liquid behaviors with the surface; surface tensions of wetting liquids can be portably indicated with a resolution scope of 0.3-3.4 mN m-1 using the surface; temperature-mediated change of liquid properties is utilized to smartly manipulate liquid behavior and achieve the spatiotemporal-controllable targeted cooling of the surface at its heated state. These novel applications open new avenues for developing advanced surfaces for liquid manipulation.

RESUMEN

Bacterial infectious diseases, especially those caused by Gram-positive bacteria, have been seriously threatening human health. Preparation of a multifunctional system bearing both rapid bacterial differentiation and effective antibacterial effects is highly in demand, but remains a severe challenge. Herein, we rationally designed and successfully developed a sequence of aggregation-induced emission luminogens (AIEgens) with orderly enhanced D-A strength. Evaluation of structure-function relationships reveals that AIEgens having intrinsic positive charge and proper ClogP value are able to stain Gram-positive bacteria. Meanwhile, one of the presented AIEgens (TTPy) can generate reactive oxygen species (ROS) in extraordinarily high efficiency under white light irradiation due to the smaller singlet-triplet energy gap. Thanks to the NIR emission, excellent specificity to Gram-positive bacteria, and effective ROS generation efficiency, TTPy has been proved to perform well in selective photodynamic killing of Gram-positive bacteria in vitro, such as S. aureus and S. epidermidis, even in S. aureus-infected rat wounds.

Asunto(s)

Antibacterianos/química , Antibacterianos/farmacología , Bacterias Grampositivas/efectos de los fármacos , Bacterias Grampositivas/efectos de la radiación , Viabilidad Microbiana/efectos de los fármacos , Viabilidad Microbiana/efectos de la radiación , Animales , Bacterias Grampositivas/fisiología , Ratas , Relación Estructura-Actividad , Factores de Tiempo

RESUMEN

Because of the abuse of antibiotics and threats of antibiotic resistance, bacterial infection is still one of the most difficult issues to be resolved. Thus, it is of great significance to explore novel antibacterial agents. In this paper, we investigated a type of silica-coated gold-silver nanocages (Au-Ag@SiO2 NCs) as antibacterial candidates. Their intrinsic characteristics of photothermal property and sustained release of Ag ions were fully exploited for near-infrared (NIR)-induced combined anti-infective therapy. The broad-spectrum antibacterial property of the as-prepared Au-Ag@SiO2 NCs was confirmed in vitro against Gram-positive Staphylococcus aureus ( S. aureus) and Gram-negative bacteria Escherichia coli ( E. coli). In addition, Au-Ag@SiO2 NCs exhibit effective treatment of the S. aureus biofilm with the assistance of NIR irradiation. More importantly, we assessed the in vivo antibacterial efficacy of Au-Ag@SiO2 NCs against S. aureus, which demonstrated sustainably enhanced therapeutic effects on a rat model with wound infection.

Asunto(s)

Antibacterianos/farmacología , Infecciones Bacterianas/tratamiento farmacológico , Biopelículas/efectos de los fármacos , Plata/química , Animales , Antibacterianos/química , Infecciones Bacterianas/genética , Infecciones Bacterianas/microbiología , Farmacorresistencia Bacteriana/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/patogenicidad , Oro/química , Humanos , Pruebas de Sensibilidad Microbiana , Ratas , Dióxido de Silicio/química , Dióxido de Silicio/farmacología , Plata/farmacología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/patogenicidad

RESUMEN

With the development of biomedical materials, the widespread use of implantable medical devices such as biomedical catheters has saved lives and improved therapeutic outcomes in the clinic. Biomedical catheters (BCs) have the ability to connect the body inside and outside and are widely used in clinical sites for fluid discharging, blood indwelling, mechanical ventilating, and so on. However, catheter-related infections (CRIs) are common nosocomial infections with high morbidity and mortality. The pathogens in the urinary tract, blood, and lung tissue carried by BCs may be the direct cause of CRIs, and the bacterial biofilm on the surface of BCs provides a notable source of persistent diseases. Microcrystalline sulfamethoxazole (SMZ) and trimethoprim (TMP) were prepared in this study to increase both the specific surface area and water-solubility of antibacterial drugs, as well as to enhance the antibacterial and antifouling effects on the surface of BCs. As-prepared drugs and the excellent antifouling agent polyethylene glycol (PEG) were then used for the functionalization of BCs. The result indicated that the sizes of microcrystalline SMZ and TMP were 0.5-3 µm, 1-5 µm, respectively. The coating of BC-PEG-drugs exhibited excellent antibacterial efficacy in culture as well as preeminent antibacterial and antifouling abilities on the surface of BCs toward Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Moreover, the BC-PEG-drugs groups exhibited outstanding antibacterial and antifouling abilities in vivo by an animal infection model with S. aureus. This study offers a simple and effective approach for the synthesis of antibacterial and antifouling coatings that consist of microcrystalline drugs, with promising clinical applicability.