Facile fabrication of malonic acid capped silver nanoparticles and their antibacterial activity

Assessment of Antimicrobial Activity of Chitosan, ZnO, and Urtica dioica-ZnO NPs Against Staphylococcus aureus Isolated from Diabetic Ulcers

Staphylococcus aureus (S. aureus) is considered as one of the challenging ulcer infections in diabetic patients especially those who have acquired antibiotic-resistant infections. Nanotechnology products have enormous potential to treat diseases including infectious diseases. As chitosan and zinc oxide (ZnO) nanoparticles (NPs) have harbored a high antimicrobial effect, this survey was aimed to synthesize chitosan, ZnO, and ZnO-Urtica. diocia (ZnO-U. diocia) NPs, and to assess their antimicrobial effects and their influence on virulence genes expression in S. aureus isolates from diabetic ulcers. The antibacterial effect of NPs was detected by microdilution method. The most frequently components in U. diocia aqueous extract were linalool,4-thujanol, camphor, carvacrol, propanedioic acid, and di(butyl) phthalate. More than 95% of clinical S. aureus isolates were resistant to several antibiotics including erythromycin, cefoxitin, clindamycin, and ciprofloxacin. The most resistant isolates were S. aureus ATDS 52, ATDS 53, F5232, and F91. The lowest MIC and MBC by the NPs on the isolates was detected as 0.128 g/mL and 0.178 g/mL, respectively. A significant decrease of 90% in the expression rates of lukED and RNAIII genes was reported for S. aureus isolates treated with the NPs. The synthetized ZnO-U. diocia and chitosan NPs can be proposed as a reliable and effective antimicrobial agent targeting diabetic ulcers infections caused by S. aureus because of its high effects on the bacterial growth and virulence genes expression.

Molecular marker identification, antioxidant, antinociceptive, and anti-inflammatory responsiveness of malonic acid capped silver nanoparticle

Nano-sized silver has drawn a great deal of attention in the field of health sciences owing to its remarkable therapeutic applications. Interestingly, the method applied to synthesize nanoparticles and the choice of reagents considerably influence their therapeutic potential and toxicities. Current research has explored the toxicity, anti-inflammatory, antinociceptive, and antioxidant responses of the malonic acid-capped silver nanoparticles (MA-AgNPs (C) by using sodium borohydride as a reducing agent at low temperatures by employing both in vitro and in vivo approaches. Furthermore, it has highlighted the synergistic effect of these novel compounds with conventional anti-inflammatory therapeutic agents. Acute and sub-acute toxicity analysis performed following OECD guidelines showed that the studied MA-AgNPs (C) are safer, and prominent toxic signs have not been detected at the highest studied dose of 2,000 mg/kg. Cytotoxicity evaluation through brine shrimp lethality revealed 20% lethality at the highest concentration of 169.8 μg/mL. Significantly, positive anti-inflammatory and analgesic responses alone as well as synergism with the standard were identified through in vitro as well as in vivo methods which were more potent at a lower dose (200 mg/kg). Notably synergistic outcomes were more pronounced than individual ones, indicating their prominent effect as a feasible drug delivery system. IL-6 and TNF-α assessment in excised paw tissue through RTPCR technique further supported their anti-inflammatory potential. DPPH assay revealed eminent in vitro antioxidant activity which was further corroborated by in vivo antioxidant assessment through evaluation of SOD in excised paw tissue.

Spectroscopic/colorimetric dual-mode rapid and ultrasensitive detection of reactive oxygen species based on shape-dependent silver nanostructures

Excessive production of reactive oxygen species (ROS) from endogenous and exogenous pathways is linked to oxidative stress and various diseases. Although a variety of ROS probes have been developed, their multistep synthesis strategies and complicated instrumental operating procedures limit their frequent use. In this work, different shaped silver nanostructures including nanoparticles, nanoprisms, and nanocubes were utilized to demonstrate simple spectroscopic and colorimetric techniques for sensitive ROS detection. The nanostructures displayed different sensing behaviours recorded via plasmon tuning with morphological changes upon exposure to ROS. Among the nanostructures, silver nanocubes were found to be extremely efficient in recognising a particular ROS, namely hypochlorite ions. The detection limits of this ROS were calculated to be 23.76 nM, 85.71 nM, and 36.37 nM for silver nanoparticles, nanoprisms, and nanocubes, respectively. A time-dependent microscopic examination was carried out and revealed that the presence of hypochlorite ions deteriorates structural morphologies. The formation of highly reactive chlorite, chlorate, and chloride ions in hypochlorite ion solution was ascribed to the significant spectroscopic and microscopic changes in all the nanostructures. The attenuation of plasmonic peaks and etching of nanostructures by ROS were supported by the increment of the oxidation state of silver. In addition, silver nanocubes were successfully applied to recognize ROS in Spinacia oleracea and real water samples. The results confirm the potentiality of silver nanostructures for sensitive detection of ROS in biological and environmental systems.

Advances in gum-based hydrogels and their environmental applications

Gum-based hydrogels (GBHs) have been widely employed in diverse water purification processes due to their environmental properties, and high absorption capacity. More desired properties of GBHs such as biodegradability, biocompatibility, material cost, simplicity of manufacture, and wide range of uses have converted them into promising materials in water treatment processes. In this review, we explored the application of GBHs to remove pollutants from contaminated waters. Water resources are constantly being contaminated by a variety of harmful effluents such as heavy metals, dyes, and other dangerous substances. A practical way to remove chemical waste from water as a vital component is surface adsorption. Currently, hydrogels, three-dimensional polymeric networks, are quite popular for adsorption. They have more extensive uses in several industries, including biomedicine, water purification, agriculture, sanitary products, and biosensors. This review will help the researcher to understand the research gaps and drawbacks in this field, which will lead to further developments in the future.

Plant extract-mediated synthesis Cobalt doping in zinc oxide nanoparticles and their in vitro cytotoxicity and antibacterial performance

In this research, zinc oxide (ZnO) nanoparticles doped with different percentages of produced cobalt using the green synthesis method. ZnO nanoparticles showed good cellular and microbial toxicity due to their high surface-to-volume ratio. Adding cobalt metal to the nanostructure can lead to the appearance of a new feature. To investigate the effect of adding cobalt metal, synthesized ZnO nanoparticles containing 3 and 6% cobalt were synthesized using plant extract. The resulting nanostructures were characterized by a Raman spectroscopy, UV-Visible spectrometer, X-ray diffraction, and Field emission scanning electron microscopy. Ultimately, the synthesized samples' cytotoxicity and antimicrobial tests were performed. XRD confirmed the formation of a hexagonal wurtzite ZnO structure. XRD and electron imaging showed that doping resulted in a decrease in average crystal size. The results showed that with cobalt doping, the particle size decreased slightly. The cytotoxicity and antimicrobial effects results showed that in all three studies, cobalt doping leads to an increase in the toxicity of this nanostructure compared to non-doped nanoparticles.

Comparative Synthesis of Silver Nanoparticles: Evaluation of Chemical Reduction Procedures, AFM and DLS Size Analysis

The size of silver nanoparticles plays a crucial role in their ultimate application in the medical and industrial fields, as their efficacy is enhanced by decreasing dimensions. This study presents two chemical synthesis procedures for obtaining silver particles and compares the results to a commercially available Ag-based product. The first procedure involves laboratory-based chemical reduction using D-glucose (C6H12O6) and NaOH as reducing agents, while the second approach utilizes trisodium citrate dehydrate (C6H5Na3O7·2H2O, TSC). The Ag nanoparticle suspensions were examined using FT-IR and UV-VIS spectroscopy, which indicated the formation of Ag particles. The dimensional properties were investigated using Atomic Force Microscopy (AFM) and confirmed by Dynamic Light Scattering (DLS). The results showed particle size from microparticles to nanoparticles, with a particle size of approximately 60 nm observed for the laboratory-based TSC synthesis approach.

Multitargeted molecular modelling of alginic acid modified with 4-aminophenol dopped with silver nanoparticles as a potent cytotoxic agent

The activity of alginic acid as a cytotoxic agent was improved by structure modification using 4-aminophenol (4-AP) through condensation and polymerization processes. Then, silver nanoparticles were employed through doping to further enhance the cytotoxic activity of the modified polymer. The structure of the prepared materials was characterized by FT-IR, ¹HNMR, UV spectroscopy, X-ray diffraction, and electron microscopy, and the thermal behavior of all synthesized materials was intensively studied. The cytotoxicity of the prepared compounds against cell lines of human hepatocellular (HepG-2) and lung (A-549) carcinomas was investigated. Alginic acid modified with 4-AP (Alg-4-AP₃) showed the highest activity against HepG-2 and A-549 among all tested materials with IC₅₀ values of 3.0 ± 0.19 μg/mL and 3.63 ± 0.23 μg/mL, respectively. Multitargeted molecular docking was employed to explore the binding modes of our compounds with the receptors EGFR, HER2, and VEGFR 2. The results revealed the inhibitory activity of our tested compounds against the proposed protein receptors, findings coincided with the in vitro results. In conclusion, the modification of alginic acid with 4-AP improved its cytotoxic activity against HepG-2 and A-549 cancer cells. In addition, doping the new materials with silver nanoparticles (AgNPs) further enhanced the cytotoxic activity.

Apoptotic, cytotoxic, antioxidant, and antibacterial activities of biosynthesized silver nanoparticles from nettle leaf

Here, we reported the biosynthesis of silver nanoparticles (AgNPs) using Urtica dioica (nettle) leaf extract as green reducing and capping agents and investigate their anticancer and antibacterial, activity. The Nettle-mediated biosynthesized AgNPs was characterized by UV-Vis a spectrophotometer. Their size, shape and elemental analysis were determined with the using of SEM and TEM. The crystal structure was determined by XRD and the biomolecules responsible for the reduction of Ag⁺ were determined using FTIR analysis. Nettle-mediated biosynthesis AgNPs indicated strong antibacterial activity against pathogenic microorganisms. Again, the antioxidant activity of AgNPs is quite high when compared to ascorbic acid. Anticancer effect of AgNPs, IC₅₀ dose was determined by XTT analysis using MCF-7 cell line and the IC₅₀ value was found to be 0.243 ± 0.014 μg/mL (% w/v).

Nano-sized and microporous palladium catalyst supported on modified chitosan/cigarette butt composite for treatment of environmental contaminants

This study reports a versatile process for the fabrication of a microporous heterogeneous palladium nanocatalyst on a novel spherical, biodegradable, and chemically/physically resistant catalyst support consisting of chitosan (CS) and cigarette waste-derived activated carbon (CAC). The physicochemical properties of the microporous Pd-CS-CAC nanocatalyst developed were successfully determined by FTIR, XRD, FE-SEM, TEM, BET, and EDS techniques. TEM studies showed that the average particle size of the synthesized Pd NPs was about 30 nm. The catalytic prowess of microporous Pd-CS-CAC was evaluated in the reduction/decolorization of various nitroarenes (2-nitroaniline (2-NA), 4-nitroaniline (4-NA), 4-nitrophenol (4-NP), and 4-nitro-o-phenylenediamine (4-NPD)) and organic dyes (methyl red (MR), methyl orange (MO), methylene blue (MB), congo red (CR), and rhodamine B (RhB)) in an aqueous medium in the presence of NaBH₄ as the reducing agent at room temperature. The catalytic activities were studied by UV-Vis absorption spectroscopy of the supernatant at regular time intervals. The short reaction times, mild reaction conditions, high efficiency (100% conversion), easy separation, and excellent chemical stability of the catalyst due to its heterogeneity and reusability are the advantages of this method. The results of the tests showed that reduction/decolorization reactions were successfully carried out within 10-140 s due to the good catalytic ability of Pd-CS-CAC. Moreover, Pd-CS-CAC was reused for 5 consecutive times with no loss of the initial shape, size, and morphology, confirming that it was a sustainable and robust nanocatalyst.

In vitro anticancer and antibacterial performance of biosynthesized Ag and Ce co-doped ZnO NPs

The great potential of zinc oxide nanoparticles (ZnO NPs) for biomedical applications is attributed to their physicochemical properties. In this work, pure and Ag and Ce dual-doped ZnO NPs were synthesized through a facile and green route to examine their cytotoxicity in breast cancer and normal cells. The initial preparation of dual-doped nanoparticles was completed by the usage of taranjabin. The synthesis of Ag and Ce dual-doped ZnO NPs was started with preparing the Ce:Ag ratios of 1:1, 1:2, and 1:4. The cytotoxicity effects of synthesized nanoparticles against breast normal cells (MCF-10A) and breast cancer cells (MDA-MB-231) were examined. The hexagonal structure of synthesized nanoparticles was observed through the results of X-ray diffraction (XRD). Scanning electron microscopy (SEM) images exhibited the spherical shape and smooth surfaces of prepared particles along with the homogeneous distribution of Ag and Ce in ZnO with high-quality lattice fringes without any distortions. According to the cytotoxic results, the effects of Ag/Ce dual-doped ZnO NPs on breast cancer (MDA-MB-231) cells were significantly more than of pure ZnO NPs, while dual-doped and pure nanoparticles remained indifferent towards breast normal (MCF-10A) cells. In addition, we investigated the antimicrobial activity against harmful bacteria.

Recent Advances in Nanotechnology for the Management of Klebsiella pneumoniae-Related Infections

Klebsiella pneumoniae is an important human pathogen that causes diseases such as urinary tract infections, pneumonia, bloodstream infections, bacteremia, and sepsis. The rise of multidrug-resistant strains has severely limited the available treatments for K. pneumoniae infections. On the other hand, K. pneumoniae activity (and related infections) urgently requires improved management strategies. A growing number of medical applications are using nanotechnology, which uses materials with atomic or molecular dimensions, to diagnose, eliminate, or reduce the activity of different infections. In this review, we start with the traditional treatment and detection method for K. pneumoniae and then concentrate on selected studies (2015-2022) that investigated the application of nanoparticles separately and in combination with other techniques against K. pneumoniae.

Amin H, F. Alanazi S, Turki Jalil A, Khatami M, Mahmood Saleh M. Trace elements-based Auroshell gold@hematite nanostructure: Green synthesis and their hyperthermia therapy

Hyperthermia is an additional treatment method to radiation therapy/chemotherapy, which increases the survival rate of patients without side effects. Nowadays, Auroshell nanoparticles have attracted much attention due to their precise control over heat use for medical purposes. In this research, iron/gold Auroshell nanoparticles were synthesised using green nanotechnology approach. Auroshell gold@hematite nanoparticles were synthesised and characterised with rosemary extract in one step and the green synthesised nanoparticles were characterised by X-ray powder diffraction, SEM, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy analysis. Cytotoxicity of Auroshell iron@gold nanoparticles against normal HUVEC cells and glioblastoma cancer cells was evaluated by 2,5-diphenyl-2H-tetrazolium bromide method, water bath hyperthermia, and combined method of water bath hyperthermia and nano-therapy. Auroshell gold@hematite nanoparticles with minimal toxicity are safe against normal cells. The gold shell around the magnetic core of magnetite caused the environmental and cellular biocompatibility of these Auroshell nanoparticles. These magnetic nanoparticles with targeted control and transfer to the tumour tissue led to uniform heating of malignant tumours as the most efficient therapeutic agent.

Synthesis characterization of Zn-based MOF and their application in degradation of water contaminants

Metal-organic frameworks (MOFs) are currently popular porous materials with research and application value in various fields such as medicine and engineering. Aiming at the application of MOFs in photocatalysis, this paper mainly reviews the main synthesis methods of ZnMOFs and the latest research progress of Zn MOF-based photocatalysts to degrade organic pollutants in water, such as organic dyes. This nanomaterial is being used to treat wastewater and has proven to be very efficient because of its exceptionally large surface area and porous nature. The results show that Zn-MOFs are capable of high degradation of the above pollutants and over 90% of degradation was observed in publications. In addition, the reusability percentage was examined and studies showed that the Zn-MOF nanostructure has very good stability and can continue to degrade a high percentage of pollutants after several cycles. This review focuses on Zn-MOFs and their composites. First, the methods of synthesis and characterization of these compounds are given. Finally, the application of these composites in the process of photocatalytic degradation of dye pollutants such as methylene blue, methyl orange, crystal violet, rhodamine B, etc. is explained.

A Cu(ii) complex supported on Fe3O4@SiO2 as a magnetic heterogeneous catalyst for the reduction of environmental pollutants

Today, the presence of pollutants in the environment has become one of the serious problems and concerns of human beings. To eliminate these pollutants, researchers have made many efforts. One of the most important of these efforts is the reduction of such contaminants in the presence of effective catalysts. Two of the most important and widespread types of these pollutants are nitro compounds and organic dyes. In this paper, we report the synthesis of an efficient and reusable magnetic catalyst using Fe3O4@SiO2 core-shell nanoparticles (NPs), N-(4-bromophenyl)-N'-benzoylthiourea, and copper(ii). Specifically, the Cu(ii)-N-(4-bromophenyl)-N'-benzoylthiourea complex supported on Fe3O4-core magnetic NPs (CM)/SiO2-shell (SS) (CM@SS-BBTU-Cu(ii)) has been prepared. CM@SS-BBTU-Cu(ii) was characterized by FT-IR (Fourier transform infrared spectroscopy), XRD (X-ray diffraction), TEM (transmission electron microscopy), HRTEM (high resolution transmission electron microscopy), FFT (fast Fourier transform), VSM (vibrating sample magnetometry), TG-DTA (thermogravimetry-differential thermal analysis), STEM (scanning transmission electron microscopy), EDS (energy-dispersive X-ray spectroscopy), and elemental mapping. The synthesized CM@SS-BBTU-Cu(ii) was applied for the reduction of 4-nitrophenol (4-NP), Congo red (CR), and methylene blue (MB) in the presence of NaBH4 (sodium borohydride) at room temperature. CM@SS-BBTU-Cu(ii) can be recycled and reused 5 times. Our results displayed that the performance of the catalyst was not significantly reduced by recycling.

Novel Carboxylic Acid-Capped Silver Nanoparticles as Antimicrobial and Colorimetric Sensing Agents

The present work reports the synthesis, characterization, and antimicrobial activities of adipic acid-capped silver nanoparticles (AgNPs@AA) and their utilization for selective detection of Hg2+ ions in an aqueous solution. The AgNPs were synthesized by the reduction of Ag+ ions with NaBH4 followed by capping with adipic acid. Characterization of as-synthesized AgNPs@AA was carried out by different techniques, including UV-Visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Dynamic Light Scattering (DLS), and zeta potential (ZP). In the UV-Vis absorption spectrum, the characteristic absorption band for AgNPs was observed at 404 nm. The hydrodynamic size of as-synthesized AgNPs was found to be 30 ± 5.0 nm. ZP values (-35.5 ± 2.4 mV) showed that NPs possessed a negative charge due to carboxylate ions and were electrostatically stabilized. The AgNPs show potential antimicrobial activity against clinically isolated pathogens. These AgNPs were found to be selectively interacting with Hg2+ in an aqueous solution at various concentrations. A calibration curve was constructed by plotting concentration as abscissa and absorbance ratio (AControl - AHg/AControl) as ordinate. The linear range and limit of detection (LOD) of Hg2+ were 0.6-1.6 μM and 0.12 μM, respectively. A rapid response time of 4 min was found for the detection of Hg2+ by the nano-probe. The effect of pH and temperature on the detection of Hg2+ was also investigated. The nano-probe was successfully applied for the detection of Hg2+ from tap and river water.

A Combinatorial Approach towards Antibacterial and Antioxidant Activity Using Tartaric Acid Capped Silver Nanoparticles

The convenient synthetic strategy for the one-pot synthesis of silver nanoparticles capped by tartaric acid with a controlled size is reported here. Their characterization is revealed through spectroscopic protocols, such as UV/Vis and FTIR, while SEM, DLS and a Zetasizer revealed the surface morphology, size distribution and surface charge on the nanoparticles. The surface plasmon resonance (SPR) band was observed at 406 nm with 1.07 a.u absorbance, the image for SEM shows that the particles were monodispersed and spherical in shape, while the z-average size distribution of AgNPs/TA in a colloidal solution was found to be 79.20 nm and the surface charge was monitored as −28.2 mV. The antibacterial activities of these capped nanoparticles alone and in synergism with selected fluoroquinolones (ofloxacin, sparfloxacin, ciprofloxacin and gemifloxacin) and macrolides (erythromycin and azithromycin) were assessed on selected Gram-negative as well as Gram-positive organisms by employing the disc diffusion method. Antioxidant activity against the DPPH (1,1-diphenyl-2-picrylhydrazyl) was also evaluated using the standard assay method. The antibacterial activity of the antibiotics has been increased against studied microorganisms, showing the positive synergistic effect of the capped nanoparticles. A potential therapeutic application of AgNPs/TA in combination with antibiotics is determined from the results of the present research. These capped nanoparticles also possess good antioxidant activity and, therefore, can be used in various fields of biomedical sciences.