A new lipoglycopeptide antibiotic family with unique structural features and pronounced activity against Gram‐positive bacteria is described by Stanislav S. Terekhov, Zakhar O. Shenkarev, Vladimir A. ...Korshun, and co‐workers in their Research Article on page 18694. Gausemycins are intrinsically fluorescent compounds with an original mode of antibacterial action. Analysis of the biosynthetic gene cluster revealed unusual enzymology, involved in the formation of a previously unknown nonproteinogenic amino acid.
•A hydrogel developed with fusiform-like ZnO(brZnO) and carboxymethyl chitosan.•The brZnO works both as crosslinker and nano-filler in the construction of hydrogel.•The hydrogel displays ...bidirectional sol–gel conversions at 42 °C and 26 °C.•The hydrogel possesses excellent injectability, self-healing, antibacterial activity.•The hydrogel creates a sterilized micro-environment that promotes wound tissue repair.
Hydrogels have attracted extensive attention as wound dressing because they can provide a moist microenvironment to accelerate wound healing. However, simple physical coverage of wound cannot satisfy the complicated process of wound repair. Here, we report an injectable multifunctional hydrogel (CMCS-brZnO) synthesized by incorporating fusiform-like zinc oxide nanorods (brZnO) into carboxymethyl chitosan (CMCS), in which the brZnO works dually as crosslinker and nano-filler. The hydrogel possesses controllable gelation time, quick self-healing, good tissue adhesion and fast hemostasis capability. Further, the CMCS-brZnO hydrogel presents excellent antibacterial properties with minimal inhibitory concentration (MIC) for E.coli and S.aureus of 0.0125 and 0.025 mg mL-1, respectively. The hydrogel could be injected directly into the irregular-shaped wounds in a full-thickness skin defect experiment, and the good fitting of the gel to the wound geometries together with the slow and sustainable release of antibacterial Zn2+ significantly promoted wound healing and reduced the inflammatory response. This study illustrates that the CMCS-brZnO hydrogels with an organic–inorganic micro-structure have great potential in accelerating wound healing.
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•Highly flexible and transparent (94.3%) sensor are fabricated through TPU and IL.•TPU/IL-based strain sensor exhibits wide strain sensing range (0.1–500%) and fast response ...(96 ms).•TPU/IL-based temperature sensor can work in a wide temperature window (−40-100 °C) with high detecting accuracy (0.1 °C).•TPU/IL sensor exhibits excellent antibacterial activity and acceptable cytocompatibility.
Skin-like sensor has recently emerged for its promising applications in human motion monitoring and healthcare. However, it is challenging to develop flexible skin-like sensors multifunctionally coupled with high transparency and strain sensitivity, accurate thermosensation, and good antibacterial activity. Herein, we fabricate flexible and transparent (94.3%) ionogels by facilely mixing ionic liquid (IL) and thermal-plastic polyurethane (TPU) to be as skin-like sensors. The prepared TPU@IL ionogel-based sensor exhibits wide strain range (0.1–500%) and fast response (96 ms) to strain stimuli. Attributed to the temperature-dependent conductivity and low freezing point of IL, the ionogels can be served as stretchable temperature sensor, containing wide operating temperature window (−40-100 °C) and high detecting accuracy (0.1 °C). Moreover, the ionogels exhibit excellent antibacterial activity. This work may inspire future research to design full-featured skin-like sensors.
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•An electrospun fibrous mat 1-PLA was prepared via an electrospinning process.•1 possesses three-dimensional framework assembled from rod-shaped molecular building blocks.•1-PLA shows ...unique broad-spectrum antibiosis potency.•1-PLA can accelerate the healing rate of infection wounds in rats.•Antibacterial mechanism was investigated by Ag+ leaching, ROS production and proteomics analysis.
The fabrication of functional wound dressings to control skin bacterial infection is of vital importance. In this work, a silver (I) metal-organic framework Ag2HBTCim (1) and polylactic acid composite fibrous mat (1-PLA) with efficient antimicrobial capability was prepared via an electrospinning process. 1 possesses three-dimensional framework assembled from rod-shaped molecular building blocks which consist of Ag (I) ions, 1,3,5-benzenetricarboxylate (HBTC) and imidazole (im) ligand. The as-prepared 1-PLA shows unique broad-spectrum antibiosis potency against Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus) and Mycobacterium smegmatis (M. smegmatis). Proteomic investigations enable to gain insight on the antimicrobial mechanism of 1-PLA composite indicating that the dissipation of proton motive force, destroying of energy metabolism, decreasing or losing of transport system may be associated with the antibacterial action. Furthermore, in vivo experiments indicate that the 1-PLA electrospun fibrous mat can significantly accelerate the healing rate of infection wounds in rats. This study demonstrated the electrospun fibrous mat with efficient on-demand antibacterial properties is promising for practical application in anti-infective therapy.
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•Extraction chlorophyll as a natural photocatalyst from fresh spinach.•Degradation of MB by PVA/Chi/TiO2/Chl bionanocomposite with noticeable efficiency.•Pathogen bacterial growth in ...PVA/TiO2/Chi/Chl were great killing in disk diffusion.•The colony counter method confirms the inhabitation growth of S. aureus and E. coli.•Green accessible materials, simple process, recycling, reusing and degradability.
In this study, using the chitosan (Chi), and poly(vinyl alcohol) (PVA) as a matrix for loading TiO2 nanoparticles (NPs), and the chlorophyll (Chl) as a natural light photocatalyst, provided the new, and efficient photocatalyst (PVA/TiO2/Chi/Chl). The TiO2 NPs and chlorophyll were applied to modify the PVA/Chi, and use as an effective nano-photocatalyst for degradation of methylene blue (MB), 4-chlorophenol (4-CP), and Congo red (CR) for the first time which shows efficiently promoted the separation of electron-hole pairs to enhance the photocatalytic activity. The degradation of MB was examined in the presence and absence of visible light. Also, the various contact time and the synergic effect of the different components of the bionanocomposite were studied. The high efficiency (96%) was achieved under visible-light irradiation (LED lamp 70 W by λ is 425 nm) at 60 min. The present bionanocomposite was identified by Fourier-transform infrared (FT-IR) spectra, field-emission scanning electron microscopy (FE-SEM) image, X-ray diffraction (XRD) pattern, and energy-dispersive X-ray (EDX), and photoluminescence (PL) analyses. Also, the antibacterial properties of PVA/TiO2/Chi/Chl as a distinctive feature were examined by the agar disk diffusion and colony counter method. The zone of inhibition for both S. aureus and E. coli bacteria were around 2.08 (±0.02), and 1.98 (±0.02), respectively. The colony counter was checked in the presence and the absence of visible light. Bacterial contamination presents serious risks to human health, therefore the prominent antimicrobial capability bionanocomposite inhibits the growth of both S. aureus, and E. coli bacteria under LED light irradiation. The use of green, and available materials, easy synthetic process, simple extraction method, eco-friendly protocol, high removal efficiency, and noticeable antibacterial properties are advantageous of the present work.
The extensive use of broad-spectrum antibiotics has resulted in antibiotic resistance for many human pathogenic bacteria making multi-drug resistance an increasing issue in the management of various ...infectious diseases. The current research focused on the green synthesis of nickel/nickel oxide nanoparticles (Nio/NiO nanoparticles) using seeds extract of Lactuca Serriola, bactericidal effect on human pathogenic bacteria and the photocatalytic activity. Highly crystalline nature of Nio/NiO nanoparticles was confirmed by X-ray diffraction (XRD). Infrared spectra of seeds extract of Lactuca Serriola (LS) evidenced the presence of many functional groups of phytochemicals acting as reducing or capping agents. From field emission scanning electron microscopic (FESEM) images of Nio/NiO nanoparticles, it was clearly observed that the particles were slightly spherical in shape with size <100 nm. The Nio/NiO nanoparticles were also tested against eight pathogenic bacteria (Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Basilus subtilis, Basilus pumilus, Micrococcus luteus, E. coli and Bordetella bronchiseptica) which displayed significant antibacterial activity at low doses and almost complete inhibition at optimized concentration. From the bandgap study, the reduced bandgap energy value of 1.57 eV indicated its potential semiconductor photocatalytic behavior. Higher degradation efficiency against the model contaminant crystal violet dye, possibility of multiple degradation mechanisms and simple recovery suggested that the green synthesized Nio/NiO nanoparticles might be best suitable candidates for environmental remediation applications.
Dyes and microbes are the main sources of water pollution and their treatment with titanium doped cobalt ferrite nanoparticles (CoTixFe2-xO4 NPs) is highly challenging due to the recombination ...ability of their electron-hole pairs which could be mitigated by making their composite with graphene oxide (GO). In the present study, titanium doped cobalt ferrite was fabricated on GO (CoTi0.2Fe1.8O4/GO NC) via the facile ultrasonication method and its confirmation was done by various analytical studies. Homogeneous dispersion of spherical CoTi0.2Fe1.8O4 NPs on the GO surface was realized by SEM analysis. Excellent crystallinity was corroborated by XRD while a Zeta Potential value −21.52 mV depicted exceptional stability. The photocatalytic power of CoTi0.2Fe1.8O/GO NC against Congo Red (CR) dye showed 91% degradation efficiency after 120 min visible light irradiation under optimum conditions of pH 9 and dye concentration 1 mg L−1 which was reasonably higher as compared to bare CoTi0.2Fe1.8O NPs (78% degradation efficiency). The improved photocatalytic performance is accredited to its narrow bandgap value (1.07 eV) and enhanced charge separation as indicated by the Tauc plot and Photoluminescence analysis, respectively. Additionally, CoTi0.2Fe1.8O/GO NC could be readily regenerated and reused five times with only ∼2% performance loss. Meanwhile, MICs of CoTi0.2Fe1.8O4/GO NC against P. aeruginosa and S. aureus were 0.046 and 0.093 mg mL−1 while MBCs were 0.093 and 0.187 mg mL−1, respectively. Thereby, optimized NC can open new avenues for the degradation of dyes from polluted water besides acting as a promising antimicrobial agent by rupturing the cell walls of pathogens.
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•Synthesis of CoTixFe2-xO4 NPs and CoTi0.2Fe1.8O4/GO NC for wastewater treatment.•Observation of decreased bandgap value with a decrease in Ti+4 ions concentration in CoTixFe2-xO4 NPs.•CoTi0.2Fe1.8O4/GO NC promoted inhibition of e−/h+ pairs recombination.•CoTi0.2Fe1.8O4/GO NC displayed enhanced CR degradation (91%) than pristine CoTixFe2-xO4 NPs.•CoTi0.2Fe1.8O4/GO NC exhibited superior antibacterial potential by rupturing the cell walls of pathogens.
•A self-healing multifunctional CA-pDA hydrogel with angiogenic and antibacterial properties was developed and evaluated.•The L-arginine coupled on chitosan endowed the hydrogel with angiogenesis ...potency.•The incorporation of pDA nanoparticles within hydrogels exhibited enhanced antibacterial activity.•The hydrogel could accelerate large skin wound healing with reduced scar formation.
Skin wound healing occurs via a series of orchestrated cellular and molecular events in a highly ordered manner, in which insufficient angiogenesis and infection at the wound site always retard the healing process. Hence, hydrogel wound dressing with multifunctional properties, including angiogenic and antibacterial properties, would be highly desired in practical application. In the present study, we developed a series of self-healing hydrogels based on L-arginine conjugated chitosan (CA), benzaldehyde group functionalized poly (ethylene glycol) (CHO-PEG-CHO), and polydopamine nanoparticles (pDA-NPs), named as CA-pDA, as an angiogenic and antibacterial dressing for wound repair. The CA-pDA hydrogels showed porous architecture, good adhesiveness and self-healing properties, as well as good biocompatibility. Particularly, the incorporation of pDA-NPs could enhance the mechanical property (~1.5–4.5 times) and pore size (~1.2 times) of pure CA hydrogel. The in vitro data demonstrated that CA hydrogel had limited capacities for inducing angiogenesis and inhibiting bacterial colony growth, while the two properties of the hydrogel could be enhanced by the incorporation of pDA-NPs. In addition, CA-pDA hydrogels, especially CA-pDA2, could accelerate wound healing with reduced scar formation in a large full-thickness skin defect (2 × 2 cm2) of a rat model. After 14 days post-surgery, the wound healing ratio in CA-pDA2 (~99%) was significantly higher than that in the control group (~79%). Collectively, the fabricated CA-pDA2 with enhanced angiogenic and antibacterial activities could have good potential for clinical wound dressing application.
The construction of heterojunctions is a recognized strategy for enhancing photogenerated carrier separation. This research introduces a novel ZnO-Ag2MoO4-AgI photocatalyst with a double Z-type ...heterojunction, made using a straightforward precipitation technique. The precise position of energy levels endowed the ternary photocatalyst with the ability of directional electron flow, while the Z-type structure exhibits strong redox capabilities and facilitates the effective separation of photogenerated charge carriers. The structural characteristics, the photocatalytic activities, the antibacterial properties, and the cytotoxicity of the catalysts were evaluated. The results demonstrate that the catalytic ability of ternary composites work synergistically, surpassing the individual and binary photocatalysts. Notably, the ternary composites with 30 % AgI content exhibit the highest catalytic activity, achieving complete degradation of Rhodamine B in 30 minutes, and up to 71.2 % degradation of Norfloxacin in 60 minutes. Furthermore, more than 99.998 % of Staphylococcus aureus, and 100 % of Escherichia coli were eliminated within 40 minutes, while Human colorectal adenocarcinoma epithelial cells mortality reached 91.98 % at a dose of 250 μg/mL. Our study underscores the potential of this strategy for photocatalytic degradation of organic contaminants, and as an antibacterial agent, providing innovative insights into the design of ZnO-based heterostructure photocatalysts.
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Effluents contaminated with antibiotics must be treated before reuse or even discharge into the aquatic environment, avoiding the increase of antimicrobial resistance (AMR) – a major public health ...problem of the 21st century. Little is known regarding the natural solar photodegradation of antibiotics in tubular reactors operated under flow mode and even less concerning the application of photocatalysts. The use of photocatalysts is considered a promising strategy for a sustainable solar-driven removal of antibiotics from effluents. In this work, the photodegradation of two antibiotics widely used in aquaculture, namely, sulfadiazine (SDZ) and oxolinic acid (OXA), was investigated under solar flow mode in the absence and presence of carbon quantum dots (CQDs) coupled with titanium dioxide (TiO2) (4% (w/w)). The obtained results showed that TiO2/CQDs (4% (w/w)) enhanced the photodegradation of both antibiotics, which is highly beneficial for their application in the treatment of aquaculture effluents. The accumulated UV energy needed for SDZ removal using the photocatalyst was less than 4 kJ L−1 in both simulated freshwater (phosphate buffer solution (PBS)) and simulated brackish water (sea salt solution (SSS)), while for OXA less than 5 kJ L−1 and around 15 kJ L−1 were needed for removal in PBS and in SSS, respectively. Moreover, results demonstrated that the proposed photocatalytic treatment was also efficient in the elimination of OXA and SDZ antibacterial activity, either in PBS or SSS. Therefore, photocatalysis under flow mode using TiO2/CQDs constitutes a promising and sustainable treatment for antibiotics’ efficient removal from aquaculture effluents.
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•Antibiotics photodegradation under continuous flow and solar radiation was assessed.•TiO2/Carbon Dots (CQDs) were tested as photocatalysts in different water matrices.•Antibiotics concentration vs accumulated UV energy fitted a pseudo-1st order model.•TiO2/CQDs provided remarkable degradation rates for sulfadiazine and oxolinic acid.•TiO2/CQDs were also proved to be efficient in reducing antibacterial activity.
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