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•A series of injectable conductive supramolecular hydrogels were synthesized.•These hydrogels showed good self-healing, photo-thermal property and biocompatibility.•The hydrogels ...exhibited great antibacterial property against E. coli, S. aureus and MRSA.•The hydrogels greatly enhanced in vivo full-thickness skin wound healing.
Hydrogel dressings with good biocompatibility and the ability to maintain a moist environment at the wound site have great potential for clinical application. Multifunctional injectable self-healing supramolecular hydrogel with conductivity and photo-thermal property as wound dressing to promote wound healing has been not reported. Herein, a series of antibacterial, injectable self-healing and conductive supramolecular hydrogels were fabricated through host-guest interaction based on quaternized chitosan-graft-cyclodextrin (QCS-CD), quaternized chitosan-graft-adamantane (QCS-AD) and graphene oxide-graft-cyclodextrin (GO-CD) polymer solutions which combined the good antibacterial activity of QCS and photo-thermal property of reduced graphene oxide (rGO). These supramolecular hydrogels wound dressings have a conductivity value similar to that of the skin and a rapid self-healing behavior, and have great antibacterial property against E. coli (gram-negative), S. aureus (gram-positive), and multi-drug resistant bacteria (such as Methicillin-resistant Staphylococcus aureus, MRSA). Furthermore, QCS-CD-AD/GO4 (0.4 wt% of rGO in the sample) shows a good balance between antibacterial activity, cell proliferation and hemocompatibility. Compared with commercial dressings (Tegaderm™ film) and QCS-CD-AD/GO0, the hydrogel QCS-CD-AD/GO4 significantly accelerated the in vivo healing process of full-thickness wounds with promoted epidermis and granulation tissue thickness, increased area coverage of collagen, and up-regulated VEGF expression. In short, these antibacterial, conductive self-healing supramolecular hydrogels are promising biomaterials as wound dressings for full-thickness skin repair.
A new complex of silver monovalent ions with benzisothiazolinone was reported. This silver coordination polymer was characterized by FTIR, elemental analysis, 1H-NMR and 13C-{1H}-NMR). These ...measurements show that the bit anion in its silver complex behaves as -bridge linking two silver(I) ions as a bidentate ligand through the oxygen and nitrogen atoms. This coordinated polymer was showed non-melting ability, high decomposition and non-solubility in water in addition to all organic solvents except the hot DMSO solvent. Therefore, this polymeric complex had has a high porosity showing thereby that an overall H2 uptake of 5.5 mmol g−1 at 77 K and 10 bar. A new method for the synthesis of a mixture of three different morphological silver nano particles (AgNPs) is reported. The new method includes reduction of the newly prepared silver-benzisothiazolinone complex, Ag(bit)n (bit = benzisothiazolinone) with sodium borohydride without using stabilizing agent. The resulting silver nanoparticles Ag NPs were characterized by UV-vis spectra, powder XRD, zeta sizer, zeta potential and scanning electron microscopy (SEM). The results showed that Ag(bit)n complex gives three different nano-sized structures spherical, wires and flakes. In order to isolate the larger proportion of the nanostructures, experiments were conducted to control the formation of one form of silver as flakes nanosilver or silver nanowires. The prepared silver nanoparticles were screened for their antibacterial activity against K. pneumonia, P. Aeruginosa, S. aureus and E. coli. Inhibition zone diameter IZD results of 2, 4 and 6 mM Ag NPs was found to be in the range of 7.0-8.4 mm for the selected bacteria.
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•Silver nanoparticles (AgNPs) acts as a potent bactericidal agent.•Release mechanism of silver (Ag+) ions from silver nanoparticles.•AgNPs and released Ag+ ions acts as effective ...antibacterial agents.•Effect of lipid and protein interactions over the toxicity of AgNPs.•DNA damage and ROS generation are correlated with toxicity of AgNPs.
Metallic nanoparticles such as silver nanoparticles (AgNPs) have gained lots of attention due to the continuous upsurge in microbial infections and diseases, and also inefficient treatment. Also, due to rapid intensification in the antibiotic resistance in this period has revived the consideration of the researchers and scientists to explore the therapeutic abilities of silver and its nanoparticulate systems as potential antimicrobial agents. Indeed, numerous studies suggested that AgNPs have exhibited significant antimicrobial actions, specifically against the bacterial infections. Ample of studies have been performed to evaluate and estimate the antibacterial potentials of silver and its associated products, and it was noticed that the they these Ag-particles triggers the oxidative stress, protein dysfunction, membrane and DNA damage, leading to microbial cell damage. Although it has exhibited antimicrobial activities, but its adverse effects over human health has been a major concern. Further, in this review we have summarized the significance of silver and AgNPs, various approaches for the preparation of AgNPs, antibacterial mechanism and probable toxicity in the cell environment. Furthermore, this review has been focused to consider the major mechanisms behind the bactericidal actions of the silver and silver nanoparticles-based systems, followed by comprehensive ideas related to their toxic potentials. This review would open new robust possibilities to develop silver nanoparticle-based antimicrobial systems with desired properties for effective treatment of bacterial infections in humans.
Hydrogels offer great potential for many biomedical and technological applications. For clinical uses, hydrogels that act as scaffold materials for cell culture, regenerative medicine, and drug ...delivery are required to have bactericidal properties. The amphiphilic peptide A9K2 was designed to effectively inhibit bacterial growth via a mechanism of membrane permeabilization. The present study demonstrated that addition of fetal bovine serum (FBS) or plasma amine oxidase (PAO) induced a sol–gel transition in A9K2 aqueous solutions. The transformation of A9K2 molecules catalyzed by lysyl oxidase (LO) in FBS or PAO accounted for the hydrogelation. Importantly, the enzymatic A9K2 hydrogel displayed high antibacterial ability against both Gram-negative and Gram-positive bacterial strains while showing extremely low mammalian cell cytotoxicity, thus demonstrating good biocompatibility. Under established coculture conditions, the peptide hydrogel showed excellent selectivity by favoring the adherence and spreading of mammalian cells, while killing pathogenic bacteria, thus avoiding bacterial contamination. These advantages endow the enzymatic A9K2 hydrogel with great potential for biomedical applications.
The aim of this study was to assess the ability of selected strains of cyanobacteria and microalgae to biosynthesize silver nanoparticles (Ag-NPs) by using two procedures; (i) suspending the live and ...washed biomass of microalgae and cyanobacteria into the AgNO
solution and (ii) by adding AgNO
into a cell-free culture liquid. Ag-NPs were biosynthesized by 14 out of 16 tested strains. In most of the cases Ag-NPs were formed both in the presence of biomass as well as in the cell-free culture liquid. This indicates that the process of Ag-NPs formation involves an extracellular compound such as polysaccharide. TEM analysis showed that the nanoparticles were embedded within an organic matrix. Ag-NPs varied in shape and sizes that ranged between 13 and 31 nm, depending on the organism used. The antibacterial activity of Ag-NPs was confirmed in all but one strain of cyanobacterium (
sp. 37-2-1) which formed the largest particles.
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Bacteria induced wound infection has become fatal healthcare issues needed to be resolved urgently. It is of vital importance to develop multifunctional therapeutic platforms to fight ...against increased bacterial antibiotic resistance. Herein, a titanium carbide (MXene)/zeolite imidazole framework-8 (ZIF-8)/polylactic acid (PLA) composite membrane (MZ-8/PLA) was fabricated through in-situ growth of ZIF-8 on MXene and the subsequent electrospinning process. It indicated MZ-8 can generate singlet oxygen and hyperthermia at photothermal (PTT) convention efficiency of 80.5% with bactericidal rate of more than 99.0%. In addition, MZ-8 showed remarkable antitumor efficiency in vitro and in vivo based on the combined photodynamic/photothermal therapy. Theoretical calculation illustrated MZ-8 could improve the laser activation process by acceleration of intermolecular charge transfer, reducing excitation energy, stabilizing excited states and increasing intersystem crossing rate. After incorporated into electrospun scaffolds, MZ-8/PLA exhibited potent PTT and photodynamic therapy (PDT) properties under 808 nm laser irradiation. The antibacterial rates of MZ-8/PLA were up to 99.9% and 99.8% against Escherichia coli and Methicillin-resistant staphylococcus aureus, respectively. In-vivo experimental results further confirmed that MZ-8/PLA can accelerate bacteria infected wound healing without observable resistance. This work opens a new avenue to design promising platforms for fighting against extremely drug resistant bacterial infection.
A cobalt-doped cadmium ferrite nanoparticle (CoxCd1-xFe2O4; x = 0, 0.2, 0.4, 0.6, 0.8, 1) was synthesized using curd as fuel during combustion. The symphonized nanoparticle's crystalline structure, ...size, morphology, photoluminescence, and optical properties are analyzed using PXRD, FTIR, SEM, HRTEM, XPS, UV–visible, and photoluminescence spectroscopies. PXRD analysis indicates that synthesized nanoparticles have a cubic spinel structure and that as cobalt doping increases, crystalline size and the lattice parameter decrease. FTIR analysis confirms tetrahedral and octahedral sites for vibrational stretching modes. Further SEM and HRTEM analyses reveal the morphology of the synthesized nanoparticles, which are agglomerated and have a nanoflakes-like structure. Furthermore, X-ray photoelectron spectroscopy reveals the elemental composition, oxidation, and transition states of CDCF NPs. UV–Vis spectroscopy discloses absorption, band gap regarding prepared NPs, and band gap deductions with increased cadmium substitution. The effect of cadmium substitution on luminescence is demonstrated by photoluminescence spectroscopy. Under visible light, photodegradation of the dye Methylene Blue in the presence of photocatalyst CDCF nanoparticles indicates that Co0.4Cd0.6Fe2O4 has higher degradation activity than other NPs. Antibacterial activity was performed for Gram-positive (S. aureus) and Gram-negative (Shigella) in the presence of synthesized Nano-particles. Activity results revealed that Co0.6Cd0.4Fe2O4 and CO0.2Cd0.8Fe2O4 NPs show an excellent zone of inhibition for S. aureus and Shigella bacterial strains.
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•SEM and HRTEM reveal nanoflake-like structures of NPs.•Synthesized NPs exhibit high visible absorption properties in UV-VIS.•Tetrahedral and octahedral stretching vibrations were confirmed by FTIR.•Cobalt doping also increases luminescence intensity in luminescence spectra.•Cadmium-substituted cobalt ferrite nanoparticles can be used in photocatalysis.
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•Silver nanoparticles were prepared using the aqueous extract of Zataria multiflora.•Biogenic nano-silvers were formed with spherical morphology.•Biogenic nano-silvers showed an ...average diameter of 25.5 nm at pH value of 9.•Biogenic nano-silvers exhibited significant antibacterial activity•Biogenic nano-silvers exhibited great biofilm inhibitory activity.
This study was aimed to fabricate Zataria multiflora-derived silver nanoparticles (AgNPs) and evaluate the antibacterial activity and biofilm inhibitory activity of plant-mediated fabricated AgNPs (P-AgNPs) compared to commercial AgNPs (C-AgNPs) against Staphylococcus aureus ATCC 25923. The P-AgNPs were characterized by using UV–vis spectroscopy, Transmission electron microscopy (TEM), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Energy Dispersive X-ray spectroscopy (EDX), Dynamic Light Scattering (DLS), and Fourier Transform Infrared (FT-IR) spectrum. The P-AgNPs were formed fairly uniform in size with a spherical morphology and an average hydrodynamic diameter of 25.5 nm at pH value of 9. Besides, the EDX analysis confirmed the presence of silver ions in the fabricated P-AgNPs. The FT-IR analysis also confirmed the presence of different functional groups on the surface of P-AgNPs. The P-AgNPs and C-AgNPs represented significant antibacterial activity with minimum inhibitory concentration (MIC) of 4 and 8 µg/mL against S. aureus, respectively. Both P-AgNPs and C-AgNPs at the concentrations of 0.5, 1, 2, and 4*MIC caused strong biofilm, weak biofilm, weak biofilm and no biofilm, respectively. Notably, at the concentrations of ≥8 µg/mL, both types of AgNPs exhibited significant biofilm inhibitory activity, whereas at the lower concentrations, the P-AgNPs showed greater biofilm inhibition formed by S. aureus.
The research reported here emphasizes the phytoextract route synthesized ZnO-doped g-C3N4 (GCN) for its photocatalytic activity, which helps to ensure a sustained & healthy environment. The leaf ...extract solution of Ficus Benjamina L. was used for the synthesis of ZnO nanoparticles, and GCN was prepared via urea using a thermal polymerization process. The flower extract functions as both stabilizers and capping agents during the process of synthesis of ZnO nanoparticles. The synthesized nanocomposites were then calcined at 400 °C and were further characterized with spectroscopy (UV–Vis), diffracted pattern (XRD), and infrared spectroscopy (FTIR). Further, the photocatalytic activity of auramine orange (AO) and methylene blue (MB) dye from phytoextract route synthesized pure ZnO NPs, GCN-Pure, and composites with varied millimolar concentrations of ZnO nanoparticles with GCN of the constant amount was checked. After the complete analysis, it was observed that the series that was prepared of ZnO-GCN nanocomposites showed notable enhancement in the degradation pattern of the methylene blue dye. Apparently, 1.5 mmol (mM) ZnO-GCN presented greater degradation patterns for Auramine orange and Methylene blue dye as compared to other nanocomposites that were synthesized. The observed increased photocatalytic activity has a conceivable explanation. The antibacterial activity studies of the prepared nanocomposites were also performed against the E. coli strain showing an enhanced zone of inhibition towards it.
Synopsis for graphical abstract:Graphical abstract shows ecofriendly phytofabrication of ZnO-doped g-C3N4 nanocomposites using Ficus Benjamin revealing its photocatalytic and antibacterial activities towards environmental applications. Display omitted
•Phytoextract mediated synthesis of ZnO nanoparticles (NPs) by using Ficus Benjamin leaf extract.•Green Synthesis of ZnO doped GCN nanocomposites (NCs) at varied molar concentrations 0.5 mM,1.0 mM, 1.5 mM, and 2.0 mM by thermal polymerization.•NCs are characterized by XRD, FTIR, SEM, TGA, and EDX mapping.•Photocatalytic activity was performed by degrading the methylene blue and auramine orange dyes.•Antibacterial activity was also performed using E. coli strain.
Bacterial resistance to antibiotics have become one of the most severe threats in global public health, so the development of new-style antimicrobial agents is urgent. In this work, quaternized ...carbon quantum dots (qCQDs) with broad-spectrum antibacterial activity were synthesized by a simple green “one-pot” method using dimethyl diallyl ammonium chloride and glucose as reaction precursors. The qCQDs displayed satisfactory antibacterial activity against both Gram-positive and gram-negative bacteria. In rat models of wounds infected with mixed bacteria, qCQDs obviously restored the weight of rats, significantly reduced the death of rats from severe infection, and promoted the recovery and healing of infected wounds. Biosafety tests confirmed that qCQDs had no obvious toxic and side effects during the testing stage. The analysis of quantitative proteomics revealed that qCQDs mainly acted on ribosomal proteins in Staphylococcus aureus (Gram-positive bacteria) and significantly down-regulated proteins associated with citrate cycle in Escherichia coli (Gram-negative bacteria). Meanwhile, real-time quantitative PCR confirmed that the variation trend of genes corresponding to the proteins associated with ribosome and citrate cycle was consistent with the proteomic results after treatment of qCQDs, suggesting that qCQDs has a new antibacterial mechanism which is different from the reported carbon quantum dots with antibacterial action.
With the development of the research on carbon quantum dots, the application of carbon quantum dots in the field of medicine has attracted extensive attention. In this paper, quaternized carbon quantum dots (qCQDs) with antimicrobial activity prepared by specific methods were studied, including antimicrobial spectrum, antimicrobial mechanism and in vivo antimicrobial application. The antimicrobial mechanism of qCQDs was studied by proteomics and RT-qRCR, and the different mechanisms of qCQDs against Gram-positive and Gram-negative bacteria were also found. This study provides a research foundation for the application of carbon quantum dots in antimicrobial field, and also expands the application range of carbon quantum dots in medicine field.
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