In this study, a novel nanofiber with improved antibacterial efficiencies was created by introducing TiO2 nanofibers and graphene oxide (GO) sheets into cellulose acetate (CA) nanofibers using an ...efficient electrospinning process. The morphologies and chemical composition of above nanocomposite were fully measured by SEM, FTIR and XRD measurements. The results demonstrated that TiO2 nanofibers and GO sheets have a uniform distribution in the CA nanofibers and these two additives also could improve hydrophilicity. TiO2/GO/CA@cotton exhibited high antibacterial activity with an inhibition rate higher than 95% against B. subtilis and B. cereus bacteria. Therefore, the proposed nanofiber is promising for the large-scale production of antibacterial nanofiber/cotton hybrid yarns for biomedical and antibacterial textiles applications.
•TiO2 and GO embedded CA nanofibers were facilely fabricated.•Electrospinning is performed to fabricate antibacterial nanofibers.•Hydrophilicity and antibacterial properties have been effectively improved.
We aimed to perform a comprehensive study on the development and characterization of silymarin (Syl)-loaded niosomes as potential drug delivery systems. The results demonstrate significant novelty ...and promising outcomes in terms of morphology, size distribution, encapsulation efficiency, in vitro release behavior, free energy profiles of Syl across the niosome bilayer, hydrogen bonding interactions, antimicrobial properties, cytotoxicity, and in vivo evaluations. The physical appearance, size, and morphology assessment of free niosomes and Syl-loaded niosomes indicated stable and well-formed vesicular structures suitable for drug delivery. Transmission electron microscopy (TEM) analysis revealed spherical shapes with distinct sizes for each formulation, confirming uniform distribution. Dynamic light scattering (DLS) analysis confirmed the size distribution results with higher polydispersity index for Syl-loaded niosomes. The encapsulation efficiency of Syl in the niosomes was remarkable at approximately 91%, ensuring protection and controlled release of the drug. In vitro release studies showed a sustained release profile for Syl-loaded niosomes, enhancing therapeutic efficacy over time. Free energy profiles analysis identified energy barriers hindering Syl permeation through the niosome bilayer, emphasizing challenges in drug delivery system design. Hydrogen bonding interactions between Syl and niosome components contributed to energy barriers, impacting drug permeability. Antimicrobial assessments revealed significant differences in inhibitory effects against S. aureus and E. coli. Cytotoxicity evaluations demonstrated the superior tumor-killing potential of Syl-loaded niosomes compared to free Syl. In vivo studies indicated niosome formulations' safety profiles in terms of liver and kidney parameters compared to bulk Syl, showcasing potential for clinical applications. Overall, this research highlights the promising potential of Syl-loaded niosomes as effective drug delivery systems with enhanced stability, controlled release, and improved therapeutic outcomes.
In order to expand the application of PLLA in the packaging field, improving its toughness and antibacterial activity has been widely concerned. However, seldom researches can simultaneously ...efficiently improve the toughness and antibacterial activity of PLLA by adding one kind of additions. To address above problems, the bifunctional branched poly(butylene adipate) ionomer additive (b-PBAUi) was synthesized. For b-PBAUi, its branched structure not only increased the plasticizing effect of additive, but also acted as reaction sites to introduce more antibacterial ionic salt. Due to the special structure of b-PBAUi, PLLA/b-PBAUi blends achieved excellent toughness and antibacterial efficiency. The elongation of blend reached 125 % even by adding 5 wt% b-PBAUi, which was 10 times higher than that of PLLA. From the analysis of phase morphology, it could be found that the microvoids promoting tensile yielding was the main tensile toughening mechanism for PLLA/b-PBAUi blends. In addition, the antibacterial activity of PLLA was significantly improved by adding b-PBAUi. For PLLA/b-PBAUi10 and PLLA/b-PBAUi15, the antibacterial efficiency against E. coli and S. aureus bacteria exceeded 99.0 %. By comprehensive consideration, the optimal blend ratio was achieved by PLLA/b-PBAUi10 due to its excellent toughness and antibacterial efficiency.
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•The nanotube layer is formed on the gas oxidation layers created on the titanium alloy.•The nanotubular structure is strongly dependent on previous gas oxidation.•The colonies of ...nanotubes of different lengths are observed.•The duplex layer demonstrates good corrosion resistance and biological properties.
The research focuses on the development and characterization of innovative thin hybrid oxide coatings obtained in subsequent processes of thermal (TO) and electrochemical (EO) oxidation. Four different surface modifications were investigated and the microstructure was determined, the mechanical, chemical and biological properties of the Ti-13Nb-13Zr alloy were assessed using scanning electron microscopy, X-ray dispersion analysis, glow discharge emission spectroscopy, Raman spectroscopy, nanoindentation and corrosion resistance measurements. The composite layers were evaluated for antimicrobial activity, cytotoxicity bioassays and wettability tests were performed. The conducted studies of two-stage oxidation (TO + EO) have shown that it is possible to obtain layers with a different structure - crystalline and nanotubular. The formation of a nanotube layer on the surface of the crystalline layer is dependent on the thickness of the crystalline layer. The produced double titanium oxide coatings show high surface roughness, high corrosion resistance, are hydrophilic, slightly antibacterial, and not cytotoxic, which has a huge impact on the process of connecting the tissue with the implant.
In this work, dual‐mode antibacterial conjugated polymer nanoparticles (DMCPNs) combined with photothermal therapy (PTT) and photodynamic therapy (PDT) are designed and explored for efficient killing ...of ampicillin‐resistant Escherichia coli (Ampr E. coli). The DMCPNs are self‐assembled into nanoparticles with a size of 50.4 ± 0.6 nm by co‐precipitation method using the photothermal agent poly(diketopyrrolopyrrole‐thienothiophene) (PDPPTT) and the photosensitizer poly2‐methoxy‐5‐((2‐ethylhexyl)oxy)‐p‐phenylenevinylene (MEH‐PPV) in the presence of poly(styrene‐co‐maleic anhydride) which makes nanoparticles disperse well in water via hydrophobic interactions. Thus, DMCPNs simultaneously possess photothermal effect and the ability of sensitizing oxygen in the surrounding to generate reactive oxygen species upon the illumination of light, which could easily damage resistant bacteria. Under combined irradiation of near‐infrared light (550 mW cm−2, 5 min) and white light (65 mW cm−2, 5 min), DMCPNs with a concentration of 9.6 × 10−4 µm could reach a 93% inhibition rate against Ampr E. coli, which is higher than the efficiency treated by PTT or PDT alone. The dual‐mode nanoparticles provide potential for treating pathogenic infections induced by resistant microorganisms in clinic.
Dual‐mode antibacterial conjugated polymer nanoparticles combined with photothermal therapy and photodynamic therapy are designed and explored for efficient killing of ampicillin‐resistant Escherichia coli.
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•We used Soxhlet apparatus for the extraction process.•Determination of chemical compounds by GCMS.•ABE@ZIF-8 nonoconjugate is synthesized.•ABE@ZIF-8 NPs are characterized using ...various techniques (UV–vis absorption spectra, PXRD, SEM, TEM, BET, TGA, DLS, zeta potential).•ABE@ZIF-8 NPs with excellent antibacterial effectiveness against gram-positive (Bacillus subtilis) and gram-negative (Pseudomonas aeruginosa) bacteria by agar diffusion method.•The zone of inhibition (ZOI) and minimum inhibitory concentration (MIC) of ABE@ZIF-8 NPs were investigated.
Certain disease-causing bacterial strains invade the body; they multiply and cause disease. The development of nanoparticles and self-assembled nanomaterial-based therapeutics has developed into a flourishing section in nanomedicine. Zeolitic imidazole framework-8 (ZIF-8) comprises zinc ions and 2-methylimidazole showing good biocompatibility, known for their large porosity with high surface area, tunable shapes, large pore sizes, and controllable surface functionality. We report a ZIF-8 based agent with excellent antibacterial effectiveness against gram-positive (Bacillus subtilis) and gram-negative (Pseudomonas aeruginosa) bacteria by agar diffusion method. We are the first to encapsulate Ajuga bracteosa extract (ABE) into the ZIF-8 framework, forming a nanoconjugate (ABE@ZIF-8). The mechanism by which the synthesized ABE@ZIF-8 NPs are inhibiting bacterial growth is likely to be the adsorbance of ABE@ZIF-8 NPs on the bacterial cell membrane because of the electrostatic attraction between positively charged ABE@ZIF-8 NPs and the negatively charged bacterial cell membrane. UV–vis absorption spectra, PXRD, SEM, TEM, BET, TGA, DLS, zeta potential characterized ABE@ZIF-8 NPs. Zone of inhibition (ZOI) and minimum inhibitory concentration (MIC) of ABE@ZIF-8 NPs are studied against the Bacillus subtilis and Pseudomonas aeruginosa compared to gentamicin, ZIF-8, ABE, and methanol. The results reported ABE@ZIF-8 nanoconjugate has better antibacterial efficiency against gram-positive and gram-negative bacteria.
Sulfaguanidine Schiff base serves as Zn2+ sensor in aqueous solution with LOD, 37.13 nM (WHO recommends 76 µM in the drinking water). Antibacterial activity of Zn2+-complex against E. coli is ...64 μg/ml which is lower than parent drug.
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(E)-N-(diaminomethylene)-4-(3,5-dichloro-2-hydroxybenzylideneamino)benzene (HL), a sulfaguanidine (SGN) appended Schiff base, acts as fluorescent ‘turn-on’ Zn2+ sensor in aqueous medium and limit of detection (LOD) is 37.13 nM which is much lower than the WHO recommended value (76 µM) in the drinking water. The composition of the complex has been supported by Job’s plot and mass spectral analysis. HL is weakly emissive which may be due to excited state induced proton transfer; however, binding with Zn2+ may stop this quenching and induce the chelation enhancement of fluorescence (CHEF) at 514 nm in presence of large number of biologically important cations. The complex shows much higher antibacterial efficiency than HL and sulfaguanidine (SGN) (MIC of SGN, >1000 μg/ml; HL, >1000 μg/ml and that of ZnL2(H2O) is 64 μg/ml for Escherichia coli). In living cells (African Monkey Vero Cells) the trace quantity of Zn2+ has been detected using the probe (HL). MTT assay confirms that the probe is non-toxic upto 200 μg/ml (774 µM). Both Density Functional Theory and molecular docking (PDB id, 5EVA) computation have been used to explain the electronic properties and to forecast the interaction of metal–ligand complex with target protein β-lactamase in bacterial cells.
•Simultaneous synthesis and deposition of ZnO nano-rods on cellulosic chains.•Hierarchical mechanism of ZnO nano-rods synthesis.•Keliab produced alkaline media activated cellulosic chains and reduced ...zinc ions.•Self-cleaning of treated cellulosic cotton optimized using statistical method.•High antibacterial efficiency obtained on treated cellulosic cotton fabric.
In situ synthesis of ZnO nanorods on cellulosic chains of cotton fabric was accomplished using natural plant source namely Keliab and zinc acetate. Hierarchical mechanism of nano ZnO generation and deposition on cellulosic chains of cotton fabric was discussed in details and several analytical techniques were used to characterize the formation of nano ZnO wurtzite structure. The morphology, crystal phase, and chemical structure of the fabric were characterized by scanning electron microscope, X-ray diffraction and energy dispersive X-ray spectroscopy. Further, interaction between ZnO and functional groups of cellulosic chains of cotton fabric was studied by Fourier transforms infrared spectroscopy. The influence of zinc acetate and Keliab solution on the self-cleaning activity of the treated cellulosic fabric was investigated with a central composite design based on surface response methodology. The treated fabrics showed self-cleaning activity toward methylene blue degradation under day light irradiation. The optimized treated sample showed high antibacterial efficiency against Staphylococcus aureus and Escherichia coli with enhanced tensile strength and higher crease recovery angle.
Two chitosan derivatives, namely, thiol-chitosan (TCs) and chitosan iodoacetamide (CsIA) were newly synthesized by reacting Cs with thiglycolic acid (TGA) and iodoacetic acid (IA) respectively. After ...being crosslinked with glutraldehyde (GA), the two derivatives were submitted to FT-IR and H1 NMR analysis for identification and characterization of their chemical features. As TCs and CsIA are water soluble, their electrospun nanofibres mats from aqueous solutions could be crosslinked and achieved using polyvinyl alcohol/Chitosan blend (PVA/Cs) polymers. Morphological structures of the obtained nanofibres and their webs were studied via those of TCs and CsIA free systems. The data also indicate that the crosslinked PVA/Cs/CsIA is more thermally stable than the crosslinked PVA/Cs/TCs and crosslinked PVA/Cs respectively. It was proved that the electrospun fibers containing TCs or CsIA display a superior antibacterial activity against negative bacteria E. Coli with a minimum inhibitory concentration (MIC) of 400μg/ml. These effects are rather in confirmation with bacterial kinetics essays which were also carried out in current work. Of particular interest is that the antimicrobial properties of fibers containing small concentration of either TCs or CsIA are much superior than those obtained with neat Cs electrospun nanofibres used as reference. By and large the results advocate the fibers webs containing TCs or CsIA as excellent candidates for wound dressing applications.
In this study, polyamide 6, polyamide 6/honey, and polyamide 6/honey/boric acid nanofibrous mats were fabricated by electrospinning and electrospraying technique to be used in wound healing ...applications. The morphology and diameter of the fiber mats with and without honey and boric acid were examined by scanning electron microscopy. The morphology of fibers showed that all resulting fibers were in the nanometer range with 253–304 nm average fiber diameter. Fourier Transform Infrared spectrum (FT-IR) and thermal gravimetric analysis (TGA) thermograms showed the successful incorporation of honey and boric acid into the fibers. The results demonstrated that increasing the amount of boric acid slightly increased the fiber diameter. Moreover, boric acid incorporation enhanced the hydrophilicity of nanofibers. The wettability and thermal stability of fibers were quite suitable for wound healing applications. Antibacterial tests demonstrated that the polyamide 6/honey fiber was effective against Escherichia coli, while the polyamide 6/honey fibers loaded with boric acid at 5 and 10 wt% concentration were effective against both Escherichia coli and Staphylococcus aureus. However, the fibers had no antibacterial activity against Acinetobacter baumannii and Pseudomonas aeruginosa. The findings showed that polyamide 6/honey and polyamide 6/honey/boric acid nanofibrous scaffolds had desirable characteristics suitable for potential wound healing applications.
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•Production of nylon 6/honey/boric acid hybrid nanofibers by electrohydrodynamic processes.•Honey and boric acid addition effected the properties of the resultant nanofibers.•Good antibacterial activity against both gram-positive and gram-negative bacteria.•Potentially applicable to wounds due to bioactivity, thermal and wettability properties.
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