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With the demand for better chronic wound care, the clinical problem of managing wound infections has already reached a critical level. Therefore, the development of novel antibiotic-free wound dressings is essential for wound care. The proteolytic enzyme bromelain, silver nanoparticles (AgNPs), and bromelain loaded on silver nanoparticles (Br-AgNPs) were assessed for their impact on wound healing in the albino mice. The formulated nanoparticles were characterized using different techniques, i.e., ultraviolet (UV), Fourier transform infrared (FTIR), and X-ray diffraction (XRD) analysis. The antibacterial and fungal activities of the formulated nanoparticles were also investigated. After 5 days of treatment, the wound healing progression and wound size reduction rate were monitored. In addition, serum and skin tissue samples were collected to assess the changes in inflammation levels and observe the histological changes. The results indicated a spherical shape and regular distribution of the synthesized gold nanoparticles, with an average particle size of 41.33–61.30 nm, where the size was about 39.84 and 82.91 nm after loading bromelain. The Br-AgNPs were the most active antimicrobial agents against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Candida albicans, as compared to the other samples and positive controls. The fibronectin and collagen III levels were significantly increased in the animal groups treated with bromelain and Br-AgNPs (7132.52 ± 324.67 and 7006.00 ± 565.19 pg/ml, respectively), compared to the negative control group. Moreover, wound closure was significantly enhanced in the Br-AgNP-treated animals compared to the other treated and control groups. The histopathological analysis supported the wound healing potential of the Br-AgNPs through their ability to induce dense fibrous connective tissue in the wound area, which was rich in irregular bundles of collagen fibers and interspersed with numerous fibroblasts. The present findings could provide valuable insight into how Br-AgNPs can accelerate wound healing, reduce recovery time, and provide an antimicrobial barrier for wounds. [ABSTRACT FROM AUTHOR]

The goal of the current work was to create an antibacterial agent by using polycaprolactone/chitosan (PCL/CH) nanofibers loaded with Cordia myxa fruit extract (CMFE) as an antimicrobial agent for wound dressing. Several characteristics, including morphological, physicomechanical, and mechanical characteristics, surface wettability, antibacterial activity, cell viability, and in vitro drug release, were investigated. The inclusion of CMFE in PCL/CH led to increased swelling capability and maximum weight loss. The SEM images of the PCL/CH/CMFE mat showed a uniform topology free of beads and an average fiber diameter of 195.378 nm. Excellent antimicrobial activity was shown towards Escherichia coli (31.34 ± 0.42 mm), Salmonella enterica (30.27 ± 0.57 mm), Staphylococcus aureus (21.31 ± 0.17 mm), Bacillus subtilis (27.53 ± 1.53 mm), and Pseudomonas aeruginosa (22.17 ± 0.12 mm) based on the inhibition zone assay. The sample containing 5 wt% CMFE had a lower water contact angle (47 ± 3.7°), high porosity, and high swelling compared to the neat mat. The release of the 5% CMFE-loaded mat was proven to be based on anomalous non-Fickian diffusion using the Korsmeyer–Peppas model. Compared to the pure PCL membrane, the PCL-CH/CMFE membrane exhibited suitable cytocompatibility on L929 cells. In conclusion, the fabricated antimicrobial nanofibrous films demonstrated high bioavailability, with suitable properties that can be used in wound dressings. [ABSTRACT FROM AUTHOR]

Bioactive plant chemicals are considered to be rich and useful for creating nanomaterials. The current work investigated the biosynthesis of silver nanoparticles (AgNPs) using ethanolic flaxseed extract as an efficient reducing factor. The production of AgNPs was verified by color-shifting observation of the mixture of silver nitrate (AgNO3) from yellow to a reddish suspension after the addition of the extract and by evaluating it by UV–visible inspection. Additionally, FTIR spectrum was used to support the identification of functional groups. The morphology and structure of AgNPs were assessed using scanning electron microscopy (SEM), and X-ray diffraction (XRD) examinations, which revealed spherical AgNPs with a diameter of 46.98 ± 12.45 nm and a crystalline structure. The zeta potential (ZP) and dynamic light scattering (DLS) measurements of AgNPs revealed values of −44.5 mV and 231.8 nm, respectively, suggesting appropriate physical stability. The antibacterial activity of AgNPs was investigated against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus pyogenes, while the antioxidant effect was investigated using the DPPH technique. These obtained AgNPs could potentially be used as efficient antibacterial and antioxidant nanomaterials. [ABSTRACT FROM AUTHOR]

Titanium dioxide nanoparticles (TiO2 NPs) are photo-active metallic nanoparticles becoming promising agents in modern biomedical applications. Herein, a novel process for the synthesis of TiO2 NPs with high stability was developed by a sol–gel process and to investigate their cytotoxicity and antibacterial activity. Numerous experiments have been performed to confirm the morphologies, compositions, and physicochemical properties of prepared TiO2 NPs, such as field emission scanning electron microscopy, dynamic light scattering, Zeta potential, Fourier transform infrared spectroscopy and X-ray diffraction. MTT assay was applied to assess the cytotoxicity of the prepared nanoparticles. The results indicate that the synthesized nanoparticles' diameter is about 68 nm and contains the anatase phase, in the range of 2θ from 25 to 80 °C. The hydrodynamic radius of nanoparticles is about 140.4 nm, and the zeta potential of nanoparticles is about −44.6 mV. The MTT results have not shown any toxicity; the antibacterial inhibitory effect of TiO2 NPs at 200 mg/mL concentrations exhibited superior antibacterial activity at 15.9 ± 0.1, 14.0 ± 0.1 against Staphylococcus aureus and Escherichia coli, respectively. In conclusion, colloidal solutions with high stability were successfully synthesized, contributing to decreased dimensions and increased antibacterial properties. [ABSTRACT FROM AUTHOR]

Nanoparticles of gold with zinc oxide (Au@ZnO NPs) were prepared by laser ablation and then capped with curcumin nanoparticles (Cur-Au@ZnO NPs). The synthesized NPs were characterized using different techniques, including transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), UV-visible spectroscopy, and X-ray diffraction. In addition, the ability of NPs as a promising antibacterial agent was tested against Staphylococcus aureus through the agar well diffusion method and AO/EtBr staining assay. The results showed that the prepared nanoparticles (Cur-Au@ZnO) served as an antibacterial agent and can destroy the bacterial cells by losing the cell wall integrity and penetrating the cytoplasmic membrane. Moreover, the findings confirmed the role of the formed NPs in attenuation of the adherence and invasion of S. aureus to rat embryonic fibroblast (REF) cells. Furthermore, the activity of Cur-Au@ZnO NPs against the S. aureus α-hemolysin toxin was evaluated using the western blot technique, using human alveolar epithelial cells (A549), and through histopathology examination in a mouse model. In conclusion, the built Cur-Au@ZnO NPs can be used as a potential antibacterial agent and an inhibitor of α-hemolysin toxin secreted by S. aureus. These NPs may offer a new strategy in combating pathogen infections and in the future for biomedical and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Carbon nanomaterials are ground-breaking two-dimensional materials with a wide range of applications because of their unique properties, which include excellent optical, electrical, thermal, and mechanical capabilities; biocompatibility; and inexpensive large-scale production costs. In this study, carbon nanostructural materials (CNMs) were effectively generated using a pulsed laser ablation method on a graphite target immersed in deionized water, and their cytotoxicity and antibacterial activities were evaluated. Lasing pulse duration, ns (1064 nm) with different laser energies (60-220 mJ), was employed for irradiating the target. The formation of CNMs was analyzed using Fourier transform infrared spectroscopy, which demonstrated that C–H, C–C, C–O, and C=C bonds were successfully formed. TEM micrographs observed CNM formation with a spherical shape and size ranging from 20 to 90 nm. The absorbance was measured using UV-Vis spectroscopy; it increased with increasing laser energy showing two broad shoulders around 210 and 305 nm. Thereafter, the antibacterial activity was tested against Escherichia coli and Staphylococcus aureus using the agar method. The results indicated that CNMs fabricated at laser energy 220 mJ have the highest activity against both strains and have presented inhibition zone (IZ) of about 34 ± 1.0 mm in S. aureus and 31 ± 1.5 mm for E. coli. A comparison with CNMs prepared at 160 mJ showed an IZ of 14 mm for S. aureus and of 12 mm for E. coli due to synergistic impact, while the cellular material release analysis displayed increased release with respect to the time of exposure due to inhibition of bacterial growth. [ABSTRACT FROM AUTHOR]

Green nanoparticle synthesis is an environmentally friendly approach that uses natural solvents. It is preferred over chemical and physical techniques due to the time and energy savings. This study aimed to synthesize zinc oxide nanoparticles (ZnO NPs) through a green method that used Phlomis leaf extract as an effective reducing agent. The synthesis and characterization of ZnO NPs were confirmed by UV-Vis spectrophotometry, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Dynamic light scattering (DLS), Zeta potential, and Field Emission Scanning Electron Microscope (FESEM) techniques. In vitro cytotoxicity was determined in L929 normal fibroblast cells using MTT assay. The antibacterial activity of ZnO nanoparticles was investigated using a disk-diffusion method against S. aureus and E. coli, as well as minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) content concentrations. XRD results confirmed the nanoparticles' crystalline structure. Nanoparticle sizes were found to be around 79 nm by FESEM, whereas the hydrodynamic radius of nanoparticles was estimated to be around 165 ± 3 nm by DLS. FTIR spectra revealed the formation of ZnO bonding and surfactant molecule adsorption on the surface of ZnO NPs. It is interesting to observe that aqueous extracts of Phlomis leave plant are efficient reducing agents for green synthesis of ZnO NPs in vitro, with no cytotoxic effect on L929 normal cells and a significant impact on the bacteria tested. [ABSTRACT FROM AUTHOR]

[Display omitted] • Antibiotic amikacin was conjugated with to gold nanoparticles (GNPs) using Pulsed laser ablation. • The GNPs and the antibiotic amikacin formulation was characterized. • The formulation was assessed for antibacterial and antibiofilm formation within contact lenses. Contact lenses are a widely utilized tool for both cosmetic and eyesight corrective purposes. Additionally, they are a direct contributor to microbial keratitis and corneal infections, particularly those caused by Pseudomonas aeruginosa infections. This study aimed to conjugate amikacin to gold nanoparticles (GNPs) and assess the formulation's antibacterial and antibiofilm formation within contact lenses. The safe and environmentally friendly method, Pulsed laser ablation (PLAL), was used to prepare the amikacin-conjugated gold nanoparticles (Am@GNPs). The characterization of the produced formula was studied using a spectrophotometer UV light, transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transforms infrared (FT-IR). Compared to the GNPs and the antibiotic amikacin, the anti-biofilm activity of Am@GNPs was measured using atomic force microscopy (AFM), whereas the antibacterial activity was measured by the well diffusion and microdilution methods against the most prevalent contact lens microbial isolates, i.e. , P. aeruginosa and Streptococcus pneumonia. The formulation, Am@GNPs, was induced higher inhibition zone and lower MIC values compared to the GNPs and the amikacin antibiotic, the effect which was more pronounced against P. aeruginosa than S. pneumonia bacterial strains. Application of Am@GNPs to the contact lenses also potentially reduced P. aeruginosa and S. pneumoniae biofilm formation, with the lowest biofilm thickness compared to the amikacin and GNPs, as demonstrated by the AFM scanning. According to current findings, the prepared Am@GNPs exhibited substantial antibacterial effects and could be a potential preservative formula for contact lenses and other eye-related medical devices. [ABSTRACT FROM AUTHOR]