Antimicrobial activity of iron oxide nanoparticle upon modulation of nanoparticle-bacteria interface

Magnetically responsive micro-clustered calcium phosphate-reinforced cell-laden microbead sodium alginate hydrogel for accelerated osteogenic tissue regeneration

The rising prevalence of bone injuries has increased the demand for minimally invasive treatments. Microbead hydrogels, renowned for cell encapsulation, provide a versatile substrate for bone tissue regeneration. They deliver bioactive agents, support cell growth, and promote osteogenesis, aiding bone repair and regeneration. In this study, we synthesized superparamagnetic iron oxide nanoparticles (Sp) coated with a calcium phosphate layer (m-Sp), achieving a distinctive flower-like micro-cluster morphology. Subsequently, sodium alginate (SA) microbead hydrogels containing m-Sp (McSa@m-Sp) were fabricated using a dropping gelation strategy. McSa@m-Sp is magnetically targetable, enhance cross-linking, control degradation rates, and provide strong antibacterial activity. Encapsulation studies with MC3T3-E1 cells revealed enhanced viability and proliferation. These studies also indicated significantly elevated alkaline phosphatase (ALP) activity and mineralization in MC3T3-E1 cells, as confirmed by Alizarin Red S (ARS) and Von Kossa staining, along with increased collagen production within the McSa@m-Sp microbead hydrogels. Immunocytochemistry (ICC) and gene expression studies supported the osteoinductive potential of McSa@m-Sp, showing increased expression of osteogenic markers including RUNX-2, collagen-I, osteopontin, and osteocalcin. Thus, McSa@m-Sp microbead hydrogels offer a promising strategy for multifunctional scaffolds in bone tissue engineering.

Mechanism of the antimicrobial activity induced by phosphatase inhibitor sodium ortho-vanadate

The present study describes a novel antimicrobial mechanism based on Sodium Orthovanadate (SOV), an alkaline phosphatase inhibitor. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and atomic force microscopy (AFM) were employed to examine the surface morphologies of the test organism, Escherichia coli (E. coli), during various antibacterial phases. Our results indicated that SOV kills bacteria by attacking cell wall growth and development, leaving E. coli's outer membrane intact. Our antimicrobial test indicated that the MIC of SOV for both E. coli and Lactococcus lactis (L. lactis) is 40 μM. A combination of quantum mechanical calculations and vibrational spectroscopy revealed that divanadate from SOV strongly coordinates with Ca2+ and Mg2+, which are the activity centers for the phosphatase that regulates bacterial cell wall synthesis. The current study is the first to propose the antibacterial mechanism caused by SOV attacking cell wall.

Application of biohybrid membranes for arsenic and chromium removal and their impact on pollutant accumulation in soybean (Glycine max L.) seedlings

Chromium and arsenic are among the priority pollutants to be controlled by regulatory and health agencies due to their ability to accumulate in food chains and the harmful effects on health resulting from the ingestion of food contaminated with metals and metalloids. In the present work, four biohybrid membrane systems were developed as alternatives for the removal of these pollutants, three based on polyvinyl alcohol polymeric mesh (PVA, PVA-magnetite, PVA L-cysteine) and one based on polybutylene adipate terephthalate (PBAT), all associated with bioremediation agents. The efficiency of the bioassociation process was assessed through count methods and microscopy. The removal capacity of these systems was evaluated in synthetic liquid medium, both in the absence and in the presence of soybean (Glycine max L.) seedlings. The content of chromium and arsenic was also analyzed in aerial and hypogeous tissues of seedlings grown on contaminated solid substrate. PVA and PVA-magnetite biohybrid membranes showed the highest removal rates, between 57 and 75% of the initial arsenic content and more than 80% of the initial chromium content after 48 h of treatment, when evaluated in synthetic liquid media with initial concentrations of 2.5 ppm of pentavalent arsenic and 5 ppm of hexavalent chromium, both in presence and absence of seedlings. PVA and PBAT promoted a significant reduction of arsenic translocation to the aerial parts, generally edible, of this crop of agronomic interest. The systems tested showed a high potential for biotechnological applications in matrices affected by the presence of arsenic and chromium.

A difficult coexistence: Resolving the iron-induced nitrification delay in groundwater filters

Rapid sand filters (RSF) are an established and widely applied technology for the removal of dissolved iron (Fe2+) and ammonium (NH4+) among other contaminants in groundwater treatment. Most often, biological NH4+oxidation is spatially delayed and starts only upon complete Fe2+ depletion. However, the mechanism(s) responsible for the inhibition of NH4+oxidation by Fe2+ or its oxidation (by)products remains elusive, hindering further process control and optimization. We used batch assays, lab-scale columns, and full-scale filter characterizations to resolve the individual impact of the main Fe2+ oxidizing mechanisms and the resulting products on biological NH4+ oxidation. modeling of the obtained datasets allowed to quantitatively assess the hydraulic implications of Fe2+ oxidation. Dissolved Fe2+ and the reactive oxygen species formed as byproducts during Fe2+ oxidation had no direct effect on ammonia oxidation. The Fe3+ oxides on the sand grain coating, commonly assumed to be the main cause for inhibited ammonia oxidation, seemed instead to enhance it. modeling allowed to exclude mass transfer limitations induced by accumulation of iron flocs and consequent filter clogging as the cause for delayed ammonia oxidation. We unequivocally identify the inhibition of NH4+oxidizing organisms by the Fe3+ flocs generated during Fe2+ oxidation as the main cause for the commonly observed spatial delay in ammonia oxidation. The addition of Fe3+ flocs inhibited NH4+oxidation both in batch and column tests, and the removal of Fe3+ flocs by backwashing completely re-established the NH4+removal capacity, suggesting that the inhibition is reversible. In conclusion, our findings not only identify the iron form that causes the inhibition, albeit the biological mechanism remains to be identified, but also highlight the ecological importance of iron cycling in nitrifying environments.

Influence of Physicochemical Properties of Iron Oxide Nanoparticles on Their Antibacterial Activity

The increasing occurrence of infectious diseases caused by antimicrobial resistance organisms urged the necessity to develop more potent, selective, and safe antimicrobial agents. The unique magnetic and tunable properties of iron oxide nanoparticles (IONPs) make them a promising candidate for different theragnostic applications, including antimicrobial agents. Though IONPs act as a nonspecific antimicrobial agent, their antimicrobial activities are directly or indirectly linked with their synthesis methods, synthesizing precursors, size, shapes, concentration, and surface modifications. Alteration of these parameters could accelerate or decelerate the production of reactive oxygen species (ROS). An increase in ROS role production disrupts bacterial cell walls, cell membranes, alters major biomolecules (e.g., lipids, proteins, nucleic acids), and affects metabolic processes (e.g., Krebs cycle, fatty acid synthesis, ATP synthesis, glycolysis, and mitophagy). In this review, we will investigate the antibacterial activity of bare and surface-modified IONPs and the influence of physiochemical parameters on their antibacterial activity. Additionally, we will report the potential mechanism of IONPs' action in driving this antimicrobial activity.

Anti-microbial, anti-biofilm, and efflux pump inhibitory effects of ellagic acid-bonded magnetic nanoparticles against Escherichia coli isolates

The spread of microbial resistance is a threat to public health. In this study, the anti-microbial, anti-biofilm, and efflux pump inhibitory effects of ellagic acid-loaded magnetic nanoparticles (Fe3O4NPs@EA) against beta-lactamase producing Escherichia coli isolates have been investigated. The effects of Fe3O4 NPs@EA on the growth inhibition of E. coli isolates were determined by disc diffusion method and determining the minimum inhibitory concentration was done using broth micro-dilution method. The anti-biofilm effect of nanoparticles was investigated using the microplate method. The efflux pump inhibitory effect of nanoparticles was investigated using cart-wheel method and by investigating the effect of nanoparticles on acrB and tolC genes expression levels. Fe3O4 NPs@EA showed anti-bacterial effects against test bacteria, and the MIC of these nanoparticles varied from 0.19 to 1.56 mg/mL. These nanoparticles caused a 43-62% reduction in biofilm formation of test bacteria compared to control. Furthermore, efflux pump inhibitory effect of these nanoparticles was confirmed at a concentration of 1/8 MIC, and the expression of acrB and tolC genes decreased in bacteria treated with 1/4 MIC Fe3O4 NPs@EA. According to the results, the use of nanoparticles containing ellagic acid can provide a basis for the development of new treatments against drug-resistant E. coli. This substance may improve the concentration of antibiotics in the bacterial cell and increase their effectiveness by inhibiting the efflux in E. coli isolates.

Biofabricated nanomaterials in sustainable agriculture: insights, challenges and prospects

One ever-evolving and ever-demanding critical human endeavour is the provision of food security for the growing world population. This can be done by adopting sustainable agriculture through horizontal (expanding the arable land area) and vertical (intensifying agriculture through sound technological approaches) interventions. Customized formulated nanomaterials have numerous advantages. With their specialized physico-chemical properties, some nanoparticulated materials improve the plant's natural development and stress tolerance and some others are good nanocarriers. Nanocarriers in agriculture often coat chemicals to form composites having utilities with crop productivity enhancement abilities, environmental management (such as ecotoxicity reduction ability) and biomedicines (such as the ability to control and target the release of useful nanoscale drugs). Ag, Fe, Zn, TiO2, ZnO, SiO2and MgO nanoparticles (NPs), often employed in advanced agriculture, are covered here. Some NPs used for various extended purposes in modern farming practices, including disease diagnostics and seed treatment are also covered. Thus, nanotechnology has revolutionized agrotechnology, which holds promise to transform agricultural (ecosystems as a whole to ensure food security in the future. Considering the available literature, this article further probes the emergent regulatory issues governing the synthesis and use of nanomaterials in the agriculture sector. If applied responsibly, nanomaterials could help improve soil health. This article provides an overview of the nanomaterials used in the distribution of biomolecules, to aid in devising a safer and eco-friendly sustainable agriculture strategy. Through this, agri-systems that depend on advanced farming practices might function more effectively and enhance agri-productivity to meet the food demand of the rising world population.

Iron Oxide Nanoparticles as Promising Antibacterial Agents of New Generation

Antimicrobial resistance (AMR) is growing into a major public health crisis worldwide. The reducing alternatives to conventional agents starve for novel antimicrobial agents. Due to their unique magnetic properties and excellent biocompatibility, iron oxide nanoparticles (IONPs) are the most preferable nanomaterials in biomedicine, including antibacterial therapy, primarily through reactive oxygen species (ROS) production. IONP characteristics, including their size, shape, surface charge, and superparamagnetism, influence their biodistribution and antibacterial activity. External magnetic fields, foreign metal doping, and surface, size, and shape modification improve the antibacterial effect of IONPs. Despite a few disadvantages, IONPs are expected to be promising antibacterial agents of a new generation.

Electrically polarized nanoscale surfaces generate reactive oxygenated and chlorinated species for deactivation of microorganisms

Because of the decreasing supply of new antibiotics, recent outbreaks of infectious diseases, and the emergence of antibiotic-resistant microorganisms, it is imperative to develop new effective strategies for deactivating a broad spectrum of microorganisms and viruses. We have implemented electrically polarized nanoscale metallic (ENM) coatings that deactivate a wide range of microorganisms including Gram-negative and Gram-positive bacteria with greater than 6-log reduction in less than 10 minutes of treatment. The electrically polarized devices were also effective in deactivating lentivirus and Candida albicans. The key to the high deactivation effectiveness of ENM devices is electrochemical production of micromolar cuprous ions, which mediated reduction of oxygen to hydrogen peroxide. Formation of highly damaging species, hydroxyl radicals and hypochlorous acid, from hydrogen peroxide contributed to antimicrobial properties of the ENM devices. The electric polarization of nanoscale coatings represents an unconventional tool for deactivating a broad spectrum of microorganisms through in situ production of reactive oxygenated and chlorinated species.

Antibiotic resistance and nanotechnology: A narrative review

The rise of antibiotic resistance poses a significant threat to public health worldwide, leading researchers to explore novel solutions to combat this growing problem. Nanotechnology, which involves manipulating materials at the nanoscale, has emerged as a promising avenue for developing novel strategies to combat antibiotic resistance. This cutting-edge technology has gained momentum in the medical field by offering a new approach to combating infectious diseases. Nanomaterial-based therapies hold significant potential in treating difficult bacterial infections by circumventing established drug resistance mechanisms. Moreover, their small size and unique physical properties enable them to effectively target biofilms, which are commonly linked to resistance development. By leveraging these advantages, nanomaterials present a viable solution to enhance the effectiveness of existing antibiotics or even create entirely new antibacterial mechanisms. This review article explores the current landscape of antibiotic resistance and underscores the pivotal role that nanotechnology plays in augmenting the efficacy of traditional antibiotics. Furthermore, it addresses the challenges and opportunities within the realm of nanotechnology for combating antibiotic resistance, while also outlining future research directions in this critical area. Overall, this comprehensive review articulates the potential of nanotechnology in addressing the urgent public health concern of antibiotic resistance, highlighting its transformative capabilities in healthcare.

Bioactivity of selenium nanoparticles biosynthesized by crude phycocyanin extract of Leptolyngbya sp. SSI24 cultivated on recycled filter cake wastes from sugar-industry

BACKGROUND

Beet filter cake (BFC) is a food-grade solid waste produced by the sugar industry, constituting a permanent source of pollution. Cyanobacteria are considered a sustainable resource for various bioactive compounds such as phycocyanin pigment with valuable applications. This study aimed to use beet filter cake extract (BFCE) as an alternative medium for the economic cultivation of cyanobacterium Leptolyngbya sp. SSI24 PP723083, then biorefined the bioactive component such as phycocyanin pigment that could be used in the production of selenium nanoparticles.

RESULTS

The results of the batch experiment displayed that the highest protein content was in BG11medium (47.9%); however, the maximum carbohydrate and lipid content were in 25% BFCE (15.25 and 10.23%, respectively). In addition, 75% BFCE medium stimulated the phycocyanin content (25.29 mg/g) with an insignificant variation compared to BG11 (22.8 mg/g). Moreover, crude phycocyanin extract from Leptolyngbya sp SSI24 cultivated on BG11 and 75% BFCE successfully produced spherical-shaped selenium nanoparticles (Se-NPs) with mean sizes of 95 and 96 nm in both extracts, respectively. Moreover, XRD results demonstrated that the biosynthesized Se-NPs have a crystalline nature. In addition, the Zeta potential of the biosynthesized Se-NPs equals - 17 mV and - 15.03 mV in the control and 75% BFCE treatment, respectively, indicating their stability. The biosynthesized Se-NPs exhibited higher effectiveness against Gram-positive bacteria than Gram-negative bacteria. Moreover, the biosynthesized Se-NPs from BG11 had higher antioxidant activity with IC50 of 60 ± 0.7 compared to 75% BFCE medium. Further, Se-NPs biosynthesized from phycocyanin extracted from Leptolyngbya sp cultivated on 75% BFCE exhibited strong anticancer activity with IC50 of 17.31 ± 0.63 µg/ml against the human breast cancer cell line.

CONCLUSIONS

The BFCE-supplemented medium can be used for the cultivation of cyanobacterial strain for the phycocyanin accumulation that is used for the green synthesis of selenium nanoparticles that have biological applications.

Nanofibers Embedded with Nanoparticles as Carriers for the Controlled Release of Anticancer Drug: Promoting the Apoptosis of Breast Cancer Cell Line and Growth Inhibition of Microbial Strains

The polymeric nanofiber mats were produced from polylactic acid, methylcellulose, and polyethylene glycol with 5-fluorouracil (5Fu) drug and iron oxide (Fe3O4) nanoparticles. Spectral and crystallographic studies clearly elucidated the ionic interactions, structure and nature of the mats. Fe3O4 nanoparticles <10 nm in size, along with methyl cellulose and polyethylene glycol, have significantly reduced the size of nanofiber mats. The mechanical properties for the mats was found to be challenging; however, surface wettability, swelling capacity, and drug encapsulation efficiency results were promising. A controlled drug release pattern was observed from in vitro drug release study, zero-order kinetics, and a Higuchi model. Nanofiber mats showed higher anticancer activity (78%) against MDA-MB 231 cancer cells, which reveals that a small amount of 5Fu drug (15.86%) with high levels of O2••, H2O2, and OH• radicals generated from Fe3O4 have catalyzed the Fenton's reaction to eradicate the cancer cells, in a shorter span of 24 h, itself. In addition, the apoptosis assay by dual AO/PI staining method clearly exhibited the apoptotic cancer cells by fluorescence microscopy. Incorporation of Fe3O4 nanoparticles enhanced the anticancer activity of the mats, compared to the commercially available standard 5Fu drug. Nanofiber mats significantly controlled the growth of selected pathogenic microbial strains by the action of the 5Fu drug and Fe3+ ions. The degradation of mats was investigated by an in vitro mass loss study for a period of 360 days. In a nutshell, promising nanofiber mats were produced as targeted drug delivery devices for chemotherapy.

Surface Modifications of Silver Nanoparticles with Chitosan, Polyethylene Glycol, Polyvinyl Alcohol, and Polyvinylpyrrolidone as Antibacterial Agents against Staphylococcus aureus, Pseudomonas aeruginosa, and Salmonella enterica

In medicine, the occurrence of antibiotic resistance was becoming a critical concern. At the same time, traditional synthesis methods of antibacterial agents often lead to environmental pollution due to the use of toxic chemicals. To address these problems, this study applies the green synthesis method to create a novel composite using a polymer blend (M8) consisting of chitosan (CS), polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and silver nanoparticles. The results show that the highest ratio of AgNO3:M8 was 0.15 g/60 mL, which resulted in a 100% conversion of Ag+ to Ag0 after 10 h of reaction at 80 °C. Hence, using M8, Ag nanoparticles (AgNPs) were synthesized at the average size of 42.48 ± 10.77 nm. The AgNPs' composite (M8Ag) was used to inhibit the growth of Staphylococcus aureus (SA), Pseudomonas aeruginosa (PA), and Salmonella enterica (SAL). At 6.25% dilution of M8Ag, the growth of these mentioned bacteria was inhibited. At the same dilution percentage of M8Ag, PA was killed.

Black seed assisted synthesis, characterization, free radical scavenging, antimicrobial and anti-inflammatory activity of iron oxide nanoparticles

Iron nanoparticles comprise a significant class of inorganic nanoparticles, which discover applications in various zones by prudence of their few exciting properties. This study achieved the green synthesis of iron oxide nanoparticles (IONPs) by black cumin seed (Nigella sativa) extract, which acts as a reducing and capping agent. The iron nanoparticles and black cumin extract were synthesized in three different concentrations: (01:01, 02:04,01:04). UV-visible spectroscopy, XRD, FTIR, and AFM characterized the synthesized iron oxide nanoparticles. UV-visible spectra show the maximum absorbance peak of 01:01 concentration at 380 nm. The other concentrations, such as 02:04, peaked at 400 nm and 01:04 at 680 nm, confirming the formation of iron oxide nanoparticles. AFM analysis reveals the spherical shape of iron oxide nanoparticles. The XRD spectra reveal the (fcc) cubic crystal structure of the iron oxide nanoparticles. The FTIR analysis's peaks at 457.13, 455.20, and 457.13 cm-1 depict the characteristic iron nanoparticle synthesis. The black cumin extract-mediated iron oxide nanoparticles show substantial antibacterial, antifungal, antioxidant and anti-inflammatory activity in a dose-dependent manner.

Biogenic Synthesis and Characterisation of Novel Potassium Nanoparticles by Capparis spinosa Flower Extract and Evaluation of Their Potential Antibacterial, Anti-biofilm and Antibiotic Development

Scientific researches on the synthesis, characterisation, and biological activity of potassium nanoparticles (K NPs) are extremely rare. In our study, we successfully synthesised a novel form of K NPs using Capparis spinosa (C. spinosa) flower extract as a reducing and capping agent. The formation of K NPs in new form (K2O NPs) was confirmed by UV-vis and XRD spectra. Furthermore, the FTIR results indicated the presence of specific active biomolecules in the C. spinosa extract which played a crucial role in reducing and stabilising K2O NPs. SEM imaging demonstrated that the K2O NPs exhibited irregular shapes with nanosizes ranging between 25 and 95 nm. Remarkably, the biosynthesised K2O NPs displayed considerable antibacterial activity against a wide range of multidrug-resistant (MDR) pathogenic bacteria. K2O NPs demonstrated considerable anti-biofilm activity against preformed biofilms produced by MDR bacteria. Combining K2O NPs with conventional antibiotics greatly improved their efficacy in compacting the MDR bacterial strains. Industrially, bulk form of potassium oxides was commonly used in the preparation of various antimicrobial compounds such as detergents, bleach, and oxidising solutions. The synthesis of potassium oxide in nanoform has shown remarkable biological efficacy, making it a promising therapeutic approach for pharmaceutical and medical applications.

Antibacterial Activity of Sustainable Thymol Nanoemulsion Formulations Against the Bacterial Blight Disease on Cluster Bean Caused by Xanthomonas axonopodis

The aim of the present study was nanoencapsulation of thymol to improve its poor water solubility and preservation of encapsulated thymol against environmental conditions. Another goal of the current investigation was to assess the antibacterial activity of thymol nanoemulsion as a sustainable biopesticide to control the bacterial blight of cluster bean. An oil-in-water (o/w) nanoemulsion containing thymol was prepared by a high-energy emulsification method using gum acacia and soya lecithin as natural emulsifiers/surfactants. The characterization of thymol nanoemulsion was carried out using dynamic light scattering (DLS), transmission electron microscope (TEM) and Fourier transform infrared spectroscopy (FTIR). A mean particle size of about 83.38 nm was recorded within 10 min of sonication. The stability analysis of optimized nanoemulsion showed kinetic stability up to two months of storage at room temperature. The thymol nanoemulsion was found to be spherical with a size ranging from 80-200 nm in diameter using transmission electron microscopy. Fourier transform infrared spectroscopy was used to study the molecular interaction between emulsifier/surfactant and thymol. The antibacterial studies of thymol nanoemulsion (0.01-0.06%, v/v) by growth inhibition analysis showed a potential antibacterial effect against Xanthomonas axonopodis pv. cyamopsidis (18-0.1 log CFU/ml). Further, in field experiments, foliar spray of the different concentration of thymol nanoemulsion (0.01-0.06%, v/v) significantly increased the percent efficiency of disease control (25.06-94.48%) and reduced the disease intensity (67.33-4.25%) of bacterial blight in cluster bean.

Inhibition of biofilm, quorum-sensing, and swarming motility in pathogenic bacteria by magnetite, manganese ferrite, and nickel ferrite nanoparticles

Resistance to antibiotics by pathogenic bacteria constitutes a health burden and nanoparticles (NPs) are being developed as alternative and multipurpose antimicrobial substances. Magnetite (Fe3O4 np), manganese ferrite (MnFe2O4 np) and nickel ferrite (NiFe3O4 np) NPs were synthesized and characterized using thermogravimetric analysis, transmission electron microscopy, Fourier transformed infra-red, and X-ray diffraction. The minimal inhibitory concentrations (MIC) ranged from 0.625 to 10 mg/mL against gram-positive (Staphylococcus aureus ATCC 25923 and Enterococcus faecalis ATCC 29212), gram-negative (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853) and candida (Candida albicans ATCC 10239 and Candida tropicalis ATCC 13803) species. The NPs exhibited violacein inhibition against Chromobacterium violaceum CV12472 of 100% at MIC and reduced to 27.2% ± 0.8% for magnetite NPs, 12.7% ± 0.3% for manganese ferrite NPs and 43.1% ± 0.2% for nickel ferrite NPs at MIC/4. Quorum-sensing (QS) inhibition zones against C. violaceum CV026 were 12.5 ±0.6 mm for Fe3O4 np, 09.1 ± 0.5 mm for MnFe3O4 NP and 17.0 ± 1.2 mm for NiFe3O4 np. The NPs inhibited swarming motility against P. aeruginosa PA01 and biofilm against six pathogens and the gram-positive biofilms were more susceptible than the gram-negative ones. The NiFe2O4 np had highest antibiofilm activity against gram-positive and gram-negative bacteria as well as highest QS inhibition while Fe3O4 NP had highest biofilm inhibition against candida species. The synthesized magnetic NPs can be used in developing anti-virulence drugs which reduce pathogenicity of bacteria as well as resistance.

Multifunctional integration of tungsten oxide (WO3) coating: A versatile approach for enhanced performance of antibiotics against single mixed bacterial infections

Nanomaterials containing tungsten (TNMs), characterized by diverse nanostructures had been extensively used in biomedical sector. Despite numerous reports focusing on TNM applications in specific biomedical areas, there is a noticeable absence of comprehensive studies that focused on detailed characterization of nanomaterials along with their biological applications. The present work described the structural, morphological, and antimicrobial properties of tungsten oxide (WO3) nanoparticles coated by antibiotics (nanobiotics), and their application on single and mixed bacterial culture. The nanobiotics included in this study were WO3 coated with ampicillin (W+A), WO3 coated with penicillin (P+W), and WO3 coated with ciprofloxacin (C+W). Techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray spectroscopy (EDX), Fourier transforms infrared spectroscopy (FTIR), Rrman spectroscopy, and UV-visible spectroscopy were used to characterize synthesized nanoparticles. The minimum inhibitory concentration of C+W nanobiotic against S. aureus, E. coli, and mixed culture (S. aureus +E. coli) was lower than that of P+W and A+W. The impact of incubation period showed significant differences for each of nanobiotic against S. aureus, E. coli, and mixed culture. However, there were also non-significant differences among incubation periods for antibacterial activity of nanobiotics. It was pertinent to note that percentage variation in susceptibility of S. aureus with respect to mixed culture remained higher as compared to E. coli, indicating it stronger candidate imposing resistance. This paper thus suggested the strategy of coating of antibiotics with with WO3 nanoparticles as an ideal combination for resistance modulation against single and mixed culture bacteria.

Facile synthesis of Fe2O3, Fe2O3@CuO and WO3 nanoparticles: characterization, structure determination and evaluation of their biological activity

Due to their high specific surface area and its characteristic's functionalized nanomaterials have great potential in medical applications specialty, as an anticancer. Herein, functional nanoparticles (NPs) based on iron oxide Fe2O3, iron oxide modified with copper oxide Fe2O3@CuO, and tungsten oxide WO3 were facile synthesized for biomedical applications. The obtained nanomaterials have nanocrystal sizes of 35.5 nm for Fe2O3, 7 nm for Fe2O3@CuO, and 25.5 nm for WO3. In addition to octahedral and square nanoplates for Fe2O3, and WO3; respectively. Results revealed that Fe2O3, Fe2O3@CuO, and WO3 NPs showed remarked anticancer effects versus a safe effect on normal cells through cytotoxicity test using MTT-assay. Notably, synthesized NPs e.g. our result demonstrated that Fe2O3@CuO exhibited the lowest IC50 value on the MCF-7 cancer cell line at about 8.876 µg/ml, compared to Fe2O3 was 12.87 µg/ml and WO3 was 9.211 µg/ml which indicate that the modification NPs Fe2O3@CuO gave the highest antiproliferative effect against breast cancer. However, these NPs showed a safe mode toward the Vero normal cell line, where IC50 were monitored as 40.24 µg/ml for Fe2O3, 21.13 µg/ml for Fe2O3@CuO, and 25.41 µg/ml for WO3 NPs. For further evidence. The antiviral activity using virucidal and viral adsorption mechanisms gave practiced effect by viral adsorption mechanism and prevented the virus from replicating inside the cells. Fe2O3@CuO and WO3 NPs showed a complete reduction in the viral load synergistic effect of combinations between the tested two materials copper oxide instead of iron oxide alone. Interestingly, the antimicrobial efficiency of Fe2O3@CuO NPs, Fe2O3NPs, and WO3NPs was evaluated using E. coli, S. aureus, and C. albicans pathogens. The widest microbial inhibition zone (ca. 38.45 mm) was observed with 250 mg/ml of WO3 NPs against E. coli, whereas using 40 mg/ml of Fe2O3@CuO NPS could form microbial inhibition zone ca. 32.86 mm against S. aureus. Nevertheless, C. albicans was relatively resistant to all examined NPs. The superior biomedical activities of these nanostructures might be due to their unique features and accepted evaluations.

Lignin nanoparticles from hydrotropic fractionation of giant reed and eucalypt: Structural elucidation and antibacterial properties

A hydrotropic solution of maleic acid (MA) was exploited to fractionate giant reed (AD) and eucalypt (EUC). The pre-treatment was successful for AD, while it was unsatisfactory for EUC, likely due to unoptimized reaction conditions. Interestingly, lignin nanoparticles (LNP) were produced via spontaneous aggregation following spent liquor dilution. LNP were studied by a plethora of analytical techniques, such as thermogravimetry, electron microscopy, and Nuclear Magnetic Resonance spectroscopy (NMR). Notwithstanding LNP from both AD and EUC showed similar thermal behaviour and morphology, a greater content of aliphatic hydroxyl, carboxyl, guaiacyl and p-hydroxyphenyl moieties was reported for AD-LNP, whereas EUC-LNP had a larger amount of syringyl groups and a higher S/G ratio. Also, the 1H-DOSY NMR indicated the lower size of AD-LNP. Moreover, the LNP were found to negatively impact on the development of several human or plant pathogens, and their bioactivity was related to the occurrence of guaiacyl and p-hydroxyphenyl moieties and a lower the LNP size. We therefore found that MA delignification allows both to achieve high delignification efficiency and to obtain LNP with promising antibacterial effect. Such LNP may help counteracting the antibiotics resistance and sustain the quest for finding sustainable agrochemicals.

Vancomycin and nisin-modified magnetic Fe3O4@SiO2 nanostructures coated with chitosan to enhance antibacterial efficiency against methicillin resistant Staphylococcus aureus (MRSA) infection in a murine superficial wound model

BACKGROUND

The objective of this research was to prepare some Fe3O4@SiO2@Chitosan (CS) magnetic nanocomposites coupled with nisin, and vancomycin to evaluate their antibacterial efficacy under both in vitro and in vivo against the methicillin-resistant Staphylococcus. aureus (MRSA).

METHODS

In this survey, the Fe3O4@SiO2 magnetic nanoparticles (MNPs) were constructed as a core and covered the surface of MNPs via crosslinking CS by glutaraldehyde as a shell, then functionalized with vancomycin and nisin to enhance the inhibitory effects of nanoparticles (NPs). X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FE-SEM), vibrating sample magnetometer (VSM), and dynamic light scattering (DLS) techniques were then used to describe the nanostructures.

RESULTS

Based on the XRD, and FE-SEM findings, the average size of the modified magnetic nanomaterials were estimated to be around 22-35 nm, and 34-47 nm, respectively. The vancomycin was conjugated in three polymer-drug ratios; 1:1, 2:1 and 3:1, with the percentages of 45.52%, 35.68%, and 24.4%, respectively. The polymer/drug ratio of 1:1 exhibited the slowest release rate of vancomycin from the Fe3O4@SiO2@CS-VANCO nanocomposites during 24 h, which was selected to examine their antimicrobial effects under in vivo conditions. The nisin was grafted onto the nanocomposites at around 73.2-87.2%. All the compounds resulted in a marked reduction in the bacterial burden (P-value < 0.05).

CONCLUSION

The vancomycin-functionalized nanocomposites exhibited to be more efficient in eradicating the bacterial cells both in vitro and in vivo. These findings introduce a novel bacteriocin-metallic nanocomposite that can suppress the normal bacterial function on demand for the treatment of MRSA skin infections.

Revisiting the smart metallic nanomaterials: advances in nanotechnology-based antimicrobials

Despite significant advancements in diagnostics and treatments over the years, the problem of antimicrobial drug resistance remains a pressing issue in public health. The reduced effectiveness of existing antimicrobial drugs has prompted efforts to seek alternative treatments for microbial pathogens or develop new drug candidates. Interestingly, nanomaterials are currently gaining global attention as a possible next-generation antibiotics. Nanotechnology holds significant importance, particularly when addressing infections caused by multi-drug-resistant organisms. Alternatively, these biomaterials can also be combined with antibiotics and other potent biomaterials, providing excellent synergistic effects. Over the past two decades, nanoparticles have gained significant attention among research communities. Despite the complexity of some of their synthesis strategies and chemistry, unrelenting efforts have been recorded in synthesizing potent and highly effective nanomaterials using different approaches. With the ongoing advancements in nanotechnology, integrating it into medical procedures presents novel approaches for improving the standard of patient healthcare. Although the field of nanotechnology offers promises, much remains to be learned to overcome the several inherent issues limiting their full translation to clinics. Here, we comprehensively discussed nanotechnology-based materials, focusing exclusively on metallic nanomaterials and highlighting the advances in their synthesis, chemistry, and mechanisms of action against bacterial pathogens. Importantly, we delve into the current challenges and prospects associated with the technology.

Metal Nanoparticles: Advanced and Promising Technology in Diabetic Wound Therapy

Diabetic wounds pose a significant challenge to public health, primarily due to insufficient blood vessel supply, bacterial infection, excessive oxidative stress, and impaired antioxidant defenses. The aforementioned condition not only places a significant physical burden on patients' prognosis, but also amplifies the economic strain on the medical system in treating diabetic wounds. Currently, the effectiveness of available treatments for diabetic wounds is limited. However, there is hope in the potential of metal nanoparticles (MNPs) to address these issues. MNPs exhibit excellent anti-inflammatory, antioxidant, antibacterial and pro-angiogenic properties, making them a promising solution for diabetic wounds. In addition, MNPs stimulate the expression of proteins that promote wound healing and serve as drug delivery systems for small-molecule drugs. By combining MNPs with other biomaterials such as hydrogels and chitosan, novel dressings can be developed and revolutionize the treatment of diabetic wounds. The present article provides a comprehensive overview of the research progress on the utilization of MNPs for treating diabetic wounds. Building upon this foundation, we summarize the underlying mechanisms involved in diabetic wound healing and discuss the potential application of MNPs as biomaterials for drug delivery. Furthermore, we provide an extensive analysis and discussion on the clinical implementation of dressings, while also highlighting future prospects for utilizing MNPs in diabetic wound management. In conclusion, MNPs represent a promising strategy for the treatment of diabetic wound healing. Future directions include combining other biological nanomaterials to synthesize new biological dressings or utilizing the other physicochemical properties of MNPs to promote wound healing. Synthetic biomaterials that contain MNPs not only play a role in all stages of diabetic wound healing, but also provide a stable physiological environment for the wound-healing process.

The Promise of Metal-Doped Iron Oxide Nanoparticles as Antimicrobial Agent

Antibiotic resistance (AMR) is one of the pressing global public health concerns and projections indicate a potential 10 million fatalities by the year 2050. The decreasing effectiveness of commercially available antibiotics due to the drug resistance phenomenon has spurred research efforts to develop potent and safe antimicrobial agents. Iron oxide nanoparticles (IONPs), especially when doped with metals, have emerged as a promising avenue for combating microbial infections. Like IONPs, the antimicrobial activities of doped-IONPs are also linked to their surface charge, size, and shape. Doping metals on nanoparticles can alter the size and magnetic properties by reducing the energy band gap and combining electronic charges with spins. Furthermore, smaller metal-doped nanoparticles tend to exhibit enhanced antimicrobial activity due to their higher surface-to-volume ratio, facilitating greater interaction with bacterial cells. Moreover, metal doping can also lead to increased charge density in magnetic nanoparticles and thereby elevate reactive oxygen species (ROS) generation. These ROS play a vital role to disrupt bacterial cell membrane, proteins, or nucleic acids. In this review, we compared the antimicrobial activities of different doped-IONPs, elucidated their mechanism(s), and put forth opinions for improved biocompatibility.

Characterization and Antibacterial Potential of Iron Oxide Nanoparticles in Eradicating Uropathogenic E. coli

Proper management and control measurements are needed to stop the spread of highly pathogenic E. coli isolates that cause urinary tract infections (UTI) by developing new antibacterial agents to ensure the safety of public health. Therefore, the present investigations were used to achieve the synthesis of iron oxide nanoparticles (IONPs) via a simple coprecipitation method using ferric nitrates Fe (NO3)3 as the precursor and hydrazine solution as the precipitator and to explore the antibacterial activity against eradicating Uropathogenic Escherichia coli (E. coli). The synthesized IONPs were further studied using a UV-vis spectrophotometer, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopic (SEM) analysis. The maximum surface plasmon resonance peak was observed as absorption at 320 nm in a colloidal solution to validate the synthesis of IONPs. The FT-IR analysis was used to identify different photoactive functional groups that were responsible for the reduction of Fe (NO3)3 to IONPs. The crystalline nature of synthesized IONPs was revealed by XRD patterns with an average particle size ranging as 29 nm. The SEM image was employed to recognize the irregular morphology of synthesized nanoparticles. Moreover, significant antibacterial activity was observed at 1 mg/mL stock solution but after (125, 250, and 500 μg/mL) dilution, the synthesized IONPs showed moderate activity and became inactive at lower concentrations. The morphological and biochemical tests were used to confirm the presence of E. coli in the samples. Furthermore, the minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) were carried out to determine the inhibitory concentrations for the isolated bacteria. The isolated E. coli were also subjected to antibiotic sensitivity testing that showed high resistance to antibiotics such as penicillin and amoxicillin. Thus, the findings of this study were to use IONPs against antibiotic resistance that has been developed in an inappropriate way.

A Comprehensive Review on Current Treatments and Challenges Involved in the Treatment of Ovarian Cancer

Ovarian cancer (OC) is the second most common gynaecological malignancy. It typically affects females over the age of 50, and since 75% of cases are only discovered at stage III or IV, this is a sign of a poor diagnosis. Despite intraperitoneal chemotherapy's chemosensitivity, most patients relapse and face death. Early detection is difficult, but treatment is also difficult due to the route of administration, resistance to therapy with recurrence, and the need for precise cancer targeting to minimize cytotoxicity and adverse effects. On the other hand, undergoing debulking surgery becomes challenging, and therapy with many chemotherapeutic medications has manifested resistance, a condition known as multidrug resistance (MDR). Although there are other therapeutic options for ovarian cancer, this article solely focuses on co-delivery techniques, which work via diverse pathways to overcome cancer cell resistance. Different pathways contribute to MDR development in ovarian cancer; however, usually, pump and non-pump mechanisms are involved. Striking cancerous cells from several angles is important to defeat MDR. Nanocarriers are known to bypass the drug efflux pump found on cellular membranes to hit the pump mechanism. Nanocarriers aid in the treatment of ovarian cancer by enhancing the delivery of chemotherapeutic drugs to the tumour sites through passive or active targeting, thereby reducing unfavorable side effects on the healthy tissues. Additionally, the enhanced permeability and retention (EPR) mechanism boosts the bioavailability of the tumour site. To address the shortcomings of conventional delivery, the current review attempts to explain the current conventional treatment with special reference to passively and actively targeted drug delivery systems (DDSs) towards specific receptors developed to treat ovarian cancer. In conclusion, tailored nanocarriers would optimize medication delivery into the intracellular compartment before optimizing intra-tumour distribution. Other novel treatment possibilities for ovarian cancer include tumour vaccines, gene therapy, targeting epigenetic alteration, and biologically targeted compounds. These characteristics might enhance the therapeutic efficacy.

In the View of Electrons Transfer and Energy Conversion: The Antimicrobial Activity and Cytotoxicity of Metal-Based Nanomaterials and Their Applications

The global pandemic and excessive use of antibiotics have raised concerns about environmental health, and efforts are being made to develop alternative bactericidal agents for disinfection. Metal-based nanomaterials and their derivatives have emerged as promising candidates for antibacterial agents due to their broad-spectrum antibacterial activity, environmental friendliness, and excellent biocompatibility. However, the reported antibacterial mechanisms of these materials are complex and lack a comprehensive understanding from a coherent perspective. To address this issue, a new perspective is proposed in this review to demonstrate the toxic mechanisms and antibacterial activities of metal-based nanomaterials in terms of energy conversion and electron transfer. First, the antimicrobial mechanisms of different metal-based nanomaterials are discussed, and advanced research progresses are summarized. Then, the biological intelligence applications of these materials, such as biomedical implants, stimuli-responsive electronic devices, and biological monitoring, are concluded based on trappable electrical signals from electron transfer. Finally, current improvement strategies, future challenges, and possible resolutions are outlined to provide new insights into understanding the antimicrobial behaviors of metal-based materials and offer valuable inspiration and instructional suggestions for building future intelligent environmental health.

Fabrication of double layer nanoparticle infused starch-based thermoplastic food packaging system for meat preservation

The current work aims to produce nanoparticle-infused starch-based bioactive thermoplastic packaging films. The FeO and ZnO nanoparticles were examined to be potential active ingredients for the production of nanoparticle-infused bioactive thermoplastic packaging films. The bio-thermoplastic films infused with FeO and ZnO nanoparticles showed high oxygen scavenging and antimicrobial activity, respectively. Consecutively, both films were combined to form a double-layer Nano-Biothermoplastic packaging system for food preservation. The distribution and diffusion of nanoparticles in starch-based films were examined to be influenced by the amorphous character of starch and the swelling index of the film, respectively. The amorphous property of starch molecules showed a masking effect on the crystalline characteristics of nanoparticles in Nano-Biothermoplastic films. The diffusion of nanoparticles from the Nano-Biothermoplastic packaging system was found to influence the microbial, chemical, and color characteristics of mutton and chicken meat stored at 4 °C.

Boosting photo-induced antimicrobial activity of lignin nanoparticles with curcumin and zinc oxide

Lignin nanoparticles have gained increasing attention as a potential antimicrobial agent due to their biocompatibility, biodegradability, and low toxicity. However, the limited ability of lignin to act as an antibacterial is a major barrier to its widespread use. Thus, it is crucial to develop novel approaches to amplify lignin's biological capabilities in order to promote its effective utilization. In this study, we modified lignin nanoparticles (LNPs) with photo-active curcumin (Cur), zinc oxide (ZnO), or a combination of both to enhance their antimicrobial properties. The successful modifications of LNPs were confirmed using comprehensive characterization techniques. The antimicrobial efficacy of the modified LNPs was assessed against both gram-positive and gram-negative bacterial strains. The results showed that the modification of LNPs with Cur and ZnO have much higher antibacterial and antibiofilm activities than unmodified LNPs. Moreover, photo illumination resulted in even higher antibacterial activity. Furthermore, atomic force microscopy revealed bacterial cells lysis and membrane damage by ZnO/Cur modified LNPs. Our research demonstrates that ZnO/Cur modified LNPs can serve as novel hybrid materials with enhanced antimicrobial capabilities. In addition, the photo-induced enhancement in antibacterial activity not only demonstrated the versatility of this hybrid material but also opened up interesting potential for bioinspired therapeutics agents.

Green synthesis of iron nanoparticles: Sources and multifarious biotechnological applications

Green synthesis of iron nanoparticles is a highly fascinating research area and has gained importance due to reliable, sustainable and ecofriendly protocol for synthesizing nanoparticles, along with the easy availability of plant materials and their pharmacological significance. As an alternate to physical and chemical synthesis, the biological materials, like microorganisms and plants are considered to be less costly and environment-friendly. Iron nanoparticles with diverse morphology and size have been synthesized using biological extracts. Microbial (bacteria, fungi, algae etc.) and plant extracts have been employed in green synthesis of iron nanoparticles due to the presence of various metabolites and biomolecules. Physical and biochemical properties of biologically synthesized iron nanoparticles are superior to that are synthesized using physical and chemical agents. Iron nanoparticles have magnetic property with thermal and electrical conductivity. Iron nanoparticles below a certain size (generally 10-20 nm), can exhibit a unique form of magnetism called superparamagnetism. They are non-toxic and highly dispersible with targeted delivery, which are suitable for efficient drug delivery to the target. Green synthesized iron nanoparticles have been explored for multifarious biotechnological applications. These iron nanoparticles exhibited antimicrobial and anticancerous properties. Iron nanoparticles adversely affect the cell viability, division and metabolic activity. Iron nanoparticles have been used in the purification and immobilization of various enzymes/proteins. Iron nanoparticles have shown potential in bioremediation of various organic and inorganic pollutants. This review describes various biological sources used in the green synthesis of iron nanoparticles and their potential applications in biotechnology, diagnostics and mitigation of environmental pollutants.

Phase variation of manganese oxide in the MnO@ZnO nanocomposite with calcination temperature and its effect on structural and biological activities

Having powerful antibacterial and antioxidant effects, zinc oxide and manganese oxide nanomaterials are of great interest. Here we have synthesized manganese oxide decorated zinc oxide (MZO) nanocomposites by co-precipitation method, calcined at different temperatures (300-750 °C) and studied various properties. Here the crystalline structure of the nanocomposite and phase change of the manganese oxide are observed with calcination temperature. The average crystalline size increases and the dislocation density and microstrain decrease with the increase in calcined temperature for the same structural features. The formation of composites was confirmed by XRD pattern and SEM images. EDAX spectra proved the high purity of the composites. Here, different biological properties change with the calcination temperature for different shapes, sizes and structures of the nanocomposite. Nanomaterial calcined at 750 °C provides the best anti-microbial activity against Escherichia coli, Salmonella typhimurium, Shigella flexneri (gram-negative), Bacillus subtilis and Bacillus megaterium (gram-positive) bacterial strain at 300 µg/mL concentration. The nanomaterial with calcination temperatures of 300 °C and 450 °C provided better antioxidant properties.

Nanoparticles and Their Antibacterial Application in Endodontics

Root canal treatment represents a significant challenge as current cleaning and disinfection methodologies fail to remove persistent bacterial biofilms within the intricate anatomical structures. Recently, the field of nanotechnology has emerged as a promising frontier with numerous biomedical applications. Among the most notable contributions of nanotechnology are nanoparticles, which possess antimicrobial, antifungal, and antiviral properties. Nanoparticles cause the destructuring of bacterial walls, increasing the permeability of the cell membrane, stimulating the generation of reactive oxygen species, and interrupting the replication of deoxyribonucleic acid through the controlled release of ions. Thus, they could revolutionize endodontics, obtaining superior results and guaranteeing a promising short- and long-term prognosis. Therefore, chitosan, silver, graphene, poly(lactic) co-glycolic acid, bioactive glass, mesoporous calcium silicate, hydroxyapatite, zirconia, glucose oxidase magnetic, copper, and zinc oxide nanoparticles in endodontic therapy have been investigated in the present review. The diversified antimicrobial mechanisms of action, the numerous applications, and the high degree of clinical safety could encourage the scientific community to adopt nanoparticles as potential drugs for the treatment of endodontic diseases, overcoming the limitations related to antibiotic resistance and eradication of the biofilm.

Synthesis and characterization of magnetic Ag-Fe3O4@polymer hybrid nanocomposite systems with promising antibacterial application

INTRODUCTION

Bacterial infections caused by different strains of bacteria still one of the most important disorders affecting humans worldwide. Polymers nanocomposite systems could be considered as an alternative to conventional antibiotics to eradicate bacterial infections.

SIGNIFICANCE

In an attempt to enhance the antibacterial performance of silver and iron oxide nanoparticles, decrease their aggregation and toxicity, a polymeric hybrid nanocomposite system combining both nanoparticles is produced.

METHODS

Magnetic Ag-Fe3O4@polymer hybrid nanocomposites prepared using different polymers, namely polyethylene glycol 4000, ethyl cellulose, and chitosan were synthesized via wet impregnation and ball-milling techniques. The produced nanocomposites were tested for their physical properties and antibacterial activities.

RESULTS

XRD, FT-IR, VSM, and TEM results confirmed the successful preparation of hybrid nanocomposites. Hybrid nanocomposites have average crystallite sizes in the following order Ag-Fe3O4@CS (8.9 nm) < Ag-Fe3O4@EC (9.0 nm) < Ag-Fe3O4@PEG4000 (9.4 nm) and active surface area of this trend Ag-Fe3O4@CS (130.4 m2g-1) > Ag-Fe3O4@EC (128.9 m2g-1) > Ag-Fe3O4@PEG4000 (123.4 m2g-1). In addition, they have a saturation magnetization in this order: Ag-Fe3O4@PEG4000 (44.82 emu/g) > Ag-Fe3O4@EC (40.14 emu/g) > Ag-Fe3O4@CS (22.90 emu/g). Hybrid nanocomposites have a pronounced antibacterial action against Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus intermedius compared to iron oxide nanoparticles and positive antibacterial drug. In addition, both Ag-Fe3O4@EC and Ag-Fe3O4@CS have a lower MIC values compared to Ag-Fe3O4@PEG and positive control.

CONCLUSION

Magnetic Ag-Fe3O4 hybrid nanocomposites could be promising antibacterial nanomaterials and could pave the way for the development of new materials with even more unique properties and applications.

Phytosynthesized Iron Oxide Nanoparticles Using Aqueous Extract of Saccharum arundinaceum (Hardy Sugar Cane), Their Characterizations, Antiglycation, and Cytotoxic Activities

The goal of the current study is to achieve plant-mediated synthesis of iron oxide nanoparticles (Fe2O3 NPs). The plant extract of Saccharum arundinaceum was used as a reducing and stabilizing agent for the synthesis of Fe2O3 NPs. Different techniques such as energy-dispersive X-ray analysis (EDX), X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and UV-visible spectroscopy (UV-vis) were used to characterize the synthesis of Fe2O3 NPs. UV-visible spectroscopy verified the synthesis of Fe2O3 NPs using a surface plasmon resonance peak at a wavelength of 370 nm. SEM analysis specifies the spherical morphology of the synthesized nanoparticles with a size range between 30 and 70 nm. The reducing and capping materials of Fe2O3 NPs were revealed by FT-IR analysis based on functional group identification. The plant extract contained essential functional groups, such as C-H, C-O, N-H, -CH2, and -OH, that facilitate the green synthesis of Fe2O3 NPs. The EDX analysis detected the atomic percentage with the elemental composition of Fe2O3 NPs, while the XRD pattern demonstrated the crystallinity of Fe2O3 NPs. Furthermore, the synthesized Fe2O3 NPs showed potential antiglycation activity under in vitro conditions, which was confirmed by the efficient zone of inhibition on glycation of bovine serum albumin/glucose (BSA-glucose) in the order <100 < 500 < 1000 μg/mL, which revealed that Fe2O3 NPs showed significant antiglycation activity. Additionally, the cytotoxic activity against brain glioblastoma cells was assessed using the MTT assay, which exhibited diminished cytotoxic activity at concentrations lower than 300 μg/mL. Thus, we assumed that the resulting Fe2O3 NPs are a good option for use in drug delivery and cancer treatments.

Novel metal peroxide nanoboxes restrain Clostridioides difficile infection beyond the bactericidal and sporicidal activity

Clostridioides difficile spores are considered as the major source responsible for the development of C. difficile infection (CDI), which is associated with an increased risk of death in patients and has become an important issue in infection control of nosocomial infections. Current treatment against CDI still relies on antibiotics, which also damage normal flora and increase the risk of CDI recurrence. Therefore, alternative therapies that are more effective against C. difficile bacteria and spores are urgently needed. Here, we designed an oxidation process using H2O2 containing PBS solution to generate Cl- and peroxide molecules that further process Ag and Au ions to form nanoboxes with Ag-Au peroxide coat covering Au shell and AgCl core (AgAu-based nanoboxes). The AgAu-based nanoboxes efficiently disrupted the membrane structure of bacteria/spores of C. difficile after 30-45 min exposure to the highly reactive Ag/Au peroxide surface of the nano structures. The Au-enclosed AgCl provided sustained suppression of the growth of 2 × 107 pathogenic Escherichia coli for up to 19 days. In a fecal bench ex vivo test and in vivo CDI murine model, biocompatibility and therapeutic efficacy of the AuAg nanoboxes to attenuate CDI was demonstrated by restoring the gut microbiota and colon mucosal structure. The treatment successfully rescued the CDI mice from death and prevented their recurrence mediated by vancomycin treatment. The significant outcomes indicated that the new peroxide-derived AgAu-based nanoboxes possess great potential for future translation into clinical application as a new alternative therapeutic strategy against CDI.

Antibacterial properties and osteoblast interactions of microfluidically synthesized chitosan - SPION composite nanoparticles

In this research, a multi-step microfluidic reactor was used to fabricate chitosan - superparamagnetic iron oxide composite nanoparticles (Ch - SPIONs), where composite formation using chitosan was aimed to provide antibacterial property and nanoparticle stability for magnetic resonance imaging (MRI). Monodispersed Ch - SPIONs had an average particle size of 8.8 ± 1.2 nm with a magnetization value of 32.0 emu/g. Ch - SPIONs could be used as an MRI contrast agent by shortening T2 relaxation parameter of the surrounding environment, as measured on a 3 T MRI scanner. In addition, Ch - SPIONs with concentrations less than 1 g/L promoted bone cell (osteoblast) viability up to 7 days of culture in vitro in the presence of 0.4 T external static magnetic field. These nanoparticles were also tested against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa), which are dangerous pathogens that cause infection in tissues and biomedical devices. Upon interaction of Ch - SPIONs with S. aureus and P. aeruginosa at 0.01 g/L concentration, nearly a 2-fold reduction in the number of colonies was observed for both bacteria strains at 48 h of culture. Results cumulatively showed that Ch - SPIONs were potential candidates as a cytocompatible and antibacterial agent that can be targeted to biofilm and imaged using an MRI.

Fimbria targeting superparamagnetic iron oxide nanoparticles enhance the antimicrobial and antibiofilm activity of ciprofloxacin against quinolone-resistant E. coli

High quinolone resistance of Escherichia coli limits the therapy options for urinary tract infection (UTI). In response to the urgent need for efficient treatment of multidrug-resistant infections, we designed a fimbriae targeting superparamagnetic iron oxide nanoparticle (SPION) delivering ciprofloxacin to ciprofloxacin-resistant E. coli. Bovine serum albumin (BSA) conjugated poly(acrylic acid) (PAA) coated SPIONs (BSA@PAA@SPION) were developed for encapsulation of ciprofloxacin and the nanoparticles were tagged with 4-aminophenyl-α-D-mannopyrannoside (mannoside, Man) to target E. coli fimbriae. Ciprofloxacin-loaded mannoside tagged nanoparticles (Cip-Man-BSA@PAA@SPION) provided high antibacterial activity (97.1 and 97.5%, respectively) with a dose of 32 μg/mL ciprofloxacin against two ciprofloxacin-resistant E. coli isolates. Furthermore, a strong biofilm inhibition (86.9% and 98.5%, respectively) was achieved in the isolates at a dose 16 and 8 times lower than the minimum biofilm eradication concentration (MBEC) of ciprofloxacin. Weaker growth inhibition was observed with untargeted nanoparticles, Cip-BSA@PAA@SPIONs, confirming that targeting E. coli fimbria with mannoside-tagged nanoparticles increases the ciprofloxacin efficiency to treat ciprofloxacin-resistant E. coli. Enhanced killing activity against ciprofloxacin-resistant E. coli planktonic cells and strong growth inhibition of their biofilms suggest that Cip-Man-BSA@PAA@SPION system might be an alternative and/or complementary therapeutic option for the treatment of quinolone-resistant E. coli infections.

Iron Nanoparticles Open Up New Directions for Promoting Healing in Chronic Wounds in the Context of Bacterial Infection

Metal nanoparticles play an outstanding role in the field of wound healing due to their excellent properties, and the significance of iron, one of the most widely used metals globally, cannot be overlooked. The purpose of this review is to determine the importance of iron nanoparticles in wound-healing dressings. Prolonged, poorly healing wounds may induce infections; wound infections are a major cause of chronic wound formation. The primary components of iron nanoparticles are iron oxide nanoparticles, which promote wound healing by being antibacterial, releasing metal ions, and overcoming bacterial resistance. The diameter of iron oxide nanoparticles typically ranges between 1 and 100 nm. Magnetic nanoparticles with a diameter of less than 30 nm are superparamagnetic and are referred to as superparamagnetic iron oxide nanoparticles. This subset of iron oxide nanoparticles can use an external magnetic field for novel functions such as magnetization and functionalization. Iron nanoparticles can serve clinical purposes not only to enhance wound healing through the aforementioned means but also to ameliorate anemia and glucose irregularities, capitalizing on iron's properties. Iron nanoparticles positively impact the healing process of chronic wounds, potentially extending beyond wound management.

Adsorption of antimicrobial peptide onto chitosan-coated iron oxide nanoparticles fosters oxidative stress triggering bacterial cell death

In the prevailing environmental status quo, bacterial resistance has made antibiotics and antimicrobial peptides (AMPs) ineffective, imparting a serious threat and putting a much greater financial burden on the biomedical and food industries. For this reason, the present study investigates the potential of iron oxide nanoparticles (IONPs) coated with chitosan (CS-IONP) as a platform for augmenting the antimicrobial activity of antimicrobial peptides like nisin. Hence, the nisin is allowed to be adsorbed onto chitosan-coated IONPs to formulate nisin-loaded CS-IONP nanoconjugates. The nanoconjugates were characterized by various optical techniques, such as XRD, FTIR, SEM, zeta and DLS. Remarkably, lower concentrations of N-CS-IONP nanoconjugate exhibited significant and broad-spectrum antibacterial potency compared to bare IONPs and nisin against both Gram-positive and Gram-negative bacteria. Biofilm production was also found to be drastically reduced in the presence of nanoconjugates. Further investigation established a relationship between an increase in antibacterial activity and the enhanced generation of reactive oxygen species (ROS). Oxidative stress exhibited due to enhanced ROS generation is a conclusive reason for the rupturing of bacterial membranes and leakage of cytoplasmic contents, eventually leading to the death of the bacteria. Thus, the current study emphasizes the formulation of a novel antimicrobial agent which exploits magnetic nanoparticles modulated with chitosan for enhanced remediation of resistant bacteria due to oxidative stress imparted by the nanoconjugates upon interaction with the bacteria, leading to cell death.

Antibacterial Properties of Methanolic Leaf Extracts of Melia azedarach L. against Gram-Positive and Gram-Negative Pathogenic Bacteria

Melia azedarach L., a Meliaceae family tree, is widely used in traditional folkloric medicine for its pharmaceutical properties. In the present study, we investigated the phytochemical composition of four methanolic leaf extracts of M. azedarach of various origins (Algeria and Tunisia) using high-performance liquid chromatography (HPLC). The antibacterial efficacy and mechanisms of action against Gram-positive and Gram-negative pathogenic microorganisms were then evaluated. Our findings revealed a presence of phenolic acids and flavonoids, such as gallic acid, chlorogenic acid, caffeic acid, hyperoside, isoquercetin, quercetin, and isorhamnetin both in Algerian and Tunisian localities, with an abundance of phenolic acids compared to flavonoids. Additionally, the studied extracts exhibit a broad spectrum of antibacterial activities, with MIC values ranging from 31.25 mg/mL to 125 mg/mL. Methanolic leaf extracts of M. azedarach from Algeria exhibited more potent biofilm eradication, with a percentage of inhibition reaching 72.17% against the S. aureus strain. Furthermore, inhibitory concentrations of tested substances, particularly the extract from the Relizane area, were capable of disrupting the membrane integrity of the treated bacteria as well as producing oxidative stress through ROS generation. Likewise, our results reveal that plant extract induces lipid peroxidation by raising MDA levels in comparison to untreated cells, particularly with the plant extract of Blida. M. azedarach extracts also reduced the synthesis of antioxidant enzymes (CAT and SOD). Our findings illustrate that M. azedarach remains a plant with significant antibacterial potential and distinct mechanisms of action that are closely related to the origins of this specimen.

Biocompatibility and Antimicrobial Profile of Acid Usnic-Loaded Electrospun Recycled Polyethylene Terephthalate (PET)-Magnetite Nanofibers

The highest amount of the world's polyethylene terephthalate (PET) is designated for fiber production (more than 60%) and food packaging (30%) and it is one of the major polluting polymers. Although there is a great interest in recycling PET-based materials, a large amount of unrecycled material is derived mostly from the food and textile industries. The aim of this study was to obtain and characterize nanostructured membranes with fibrillar consistency based on recycled PET and nanoparticles (Fe3O4@UA) using the electrospinning technique. The obtained fibers limit microbial colonization and the development of biofilms. Such fibers could significantly impact modern food packaging and the design of improved textile fibers with antimicrobial effects and good biocompatibility. In conclusion, this study suggests an alternative for PET recycling and further applies it in the development of antimicrobial biomaterials.

Chemical Composition of Ailanthus altissima (Mill.) Swingle Methanolic Leaf Extracts and Assessment of Their Antibacterial Activity through Oxidative Stress Induction

The present study was conducted to investigate the chemical composition of Ailanthus altissima (Mill.) Swingle methanolic leaf extracts from geographically distinct regions and to assess their antimicrobial properties along with their ability to induce oxidative stress. The HPLC-DAD analysis revealed the presence of phenolic acids and flavonoids including chlorogenic acid, gallic acid, synapic acid, p-coumaric acid, apigenin, hyperoside, isoamnétine-3-O-beta-D-glucotrioside, quercetin, and isoquercetin in various amounts depending on the origin of tested extracts. The assessment of antibacterial activity showed the effectiveness of the A. altissima extracts particularly against Gram-positive bacteria, with inhibition zone diameters reaching 14 ± 1 mm and minimum inhibitory concentrations ranging from 4 to 72.2 mg/mL. These bioactive substances also exhibited strong antibiofilm activity with an eradication percentage reaching 67.07%. Furthermore, they increased ROS production to levels two to five times higher than the control group, altered the membrane integrity and caused lipid peroxidation with MDA production exceeding 2.5 µmol/mg protein in the Gram-positive and Gram-negative strains. A decrease in the levels of the antioxidant enzymes SOD and CAT was also observed, indicating an impairment of the bacterial response to the oxidative stress caused by the tested extracts. These findings highlight the antibacterial properties of A. altissima leaf extracts depending on their origins and promote their exploitation and application in the agro-food and pharmaceutical sectors.

Nanobiotics and the One Health Approach: Boosting the Fight against Antimicrobial Resistance at the Nanoscale

Antimicrobial resistance (AMR) is a growing public health concern worldwide, and it poses a significant threat to human, animal, and environmental health. The overuse and misuse of antibiotics have contributed significantly and others factors including gene mutation, bacteria living in biofilms, and enzymatic degradation/hydrolyses help in the emergence and spread of AMR, which may lead to significant economic consequences such as reduced productivity and increased health care costs. Nanotechnology offers a promising platform for addressing this challenge. Nanoparticles have unique properties that make them highly effective in combating bacterial infections by inhibiting the growth and survival of multi-drug-resistant bacteria in three areas of health: human, animal, and environmental. To conduct an economic evaluation of surveillance in this context, it is crucial to obtain an understanding of the connections to be addressed by several nations by implementing national action policies based on the One Health strategy. This review provides an overview of the progress made thus far and presents potential future directions to optimize the impact of nanobiotics on AMR.

Enhancing the antibacterial effect of iron oxide and silver nanoparticles by extremely low frequency electric fields (ELF-EF) against S. aureus

Staphylococcus aureus is the cause of many infectious and inflammatory diseases and a lot of studies aim to discover alternative ways for infection control and treatment rather than antibiotics. This work attempts to reduce bacterial activity and growth characteristics of Staphylococcus aureus using nanoparticles (iron oxide nanoparticles and silver nanoparticles) and extremely low frequency electric fields (ELF-EF). Bacterial suspensions of Staphylococcus aureus were used to prepare the samples, which were evenly divided into groups. Control group, 10 groups were exposed to ELF-EF in the frequency range (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1 Hz), iron oxide NPs treated group, iron oxide NPs exposed to 0.8 Hz treated group, silver NPs treated group and the last group was treated with silver NPs and 0.8 Hz. Antibiotic sensitivity testing, dielectric relaxation, and biofilm development for the living microbe were used to evaluate morphological and molecular alterations. Results showed that combination of nanoparticles with ELF-EF at 0.8 Hz enhanced the bacterial inhibition efficiency, which may be due to structural changes. These were supported by the dielectric measurement results which indicated the differences in the dielectric increment and electrical conductivity for the treated samples compared with control samples. This was also confirmed by biofilm formation measurements obtained. We may conclude that the exposure of Staphylococcus aureus bacteria to ELF-EF and NPs affected its cellular activity and structure. This technique is nondestructive, safe and fast and could be considered as a mean to reduce the use of antibiotics.

Acid protease functionalized novel silver nanoparticles (APTs-AgNPs): A new approach towards photocatalytic and biological applications

Herein, we described for the first time, an efficient biogenic synthesis of APTs-AgNPs using acid protease from Melilotus indicus leaf extract. The acid protease (APTs) has an essential role in the stabilization, reduction, and capping of APTs-AgNPs. The crystalline nature, size, and surface morphology of APTs-AgNPs were examined using different techniques such as XRD, UV, FTIR, SEM, EDS, HRTEM, and DLS analysis. The generated APTs-AgNPs demonstrated notable performance as dual functionality (photocatalyst and antibacterial disinfection). By destroying 91 % of methylene blue (MB) in <90 min of exposure, APTs-AgNPs demonstrated remarkable photocatalytic activity. APTs-AgNPs also showed remarkable stability as a photocatalyst after five test cycles. Furthermore, the APTs-AgNPs was found to be a potent antibacterial agent with inhibition zones of 30(±0.5 mm), 27(±0.4 mm), 16(±0.1 mm), and 19(±0.7 mm) against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, respectively, under both light and dark conditions. Furthermore, APTs-AgNPs effectively scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, demonstrating their potent antioxidant activity. The outcomes of this study thus demonstrates the dual functionality of APTs-AgNPs produced using the biogenic approach method as a photocatalyst and an antibacterial agent for effective microbial and environmental control.

Rapid photodegradation of toxic organic compounds and photo inhibition of bacteria in the presence of novel hydrothermally synthesized Ag/Mn-ZnO nanomaterial

Purified water is the most concerning issue these days, and utmost conventional practices are allied with various downsides. Therefore, an ecologically benign and easily amicable therapeutic approach is the requirement. In this wonder, nanometer phenomena bring an innovative change to the material world. It has the potential to produce nanosized materials for wide-ranging applications. The subsequent research highlights the synthesis of Ag/Mn-ZnO nanomaterial via a one-pot hydrothermal route with an efficient photocatalytic activity against organic dyes and bacteria. The outcomes revealed that the size of the particle (4-5 nm) and dispersion of spherically shaped silver nanoparticles intensely affected by employing Mn-ZnO as a support material. Use of silver NPs as a dopant activates the active sites of the support medium and provides a higher surface area to upsurge the degradation rate. The synthesized nanomaterial was evaluated against photocatalytic activity using Methyl orange and alizarin red as model dyes and confided that more than 70% of both the dyes degraded under 100 min duration. It is well recognize that the modified nanomaterial recreates an essential role in every light-based reaction, and virtually produced highly reactive oxygen species. The synthesized nanomaterial was also evaluated against E. coli bacterium both in light and dark. The zone of inhibition in the presence of Ag/Mn-ZnO was observed both in light (18 ± 0.2 mm) and dark (12 ± 0.4 mm). The hemolytic activity shows that Ag/Mn-ZnO has very low toxicity. Hence, the prepared Ag/Mn-ZnO nanomaterial might be an effective tool against the depletion of further harmful environmental pollutants and microbes.

Cyanobacteria control using Cu-based metal organic frameworks derived from waste PET bottles

Copper sulfate (CuSO₄) is actively used to control the proliferation of harmful algal blooms because of its fast and effective killing mechanism. However, its use unintentionally harms innocuous aquatic organisms. Therefore, there is a need to find non-toxic solutions for controlling algal blooms. In this study, Cu-based metal-organic framework (Cu-BDC MOF) chips (ca. 2 × 2 cm) were synthesized using waste polyethylene terephthalate (PET) bottles. The as-synthesized Cu-BDC MOF chips efficiently inhibited the cyanobacteria species Microcystis aeruginosa, which was comparable to the conventional dose of CuSO₄ algaecide (1.00 mg L^-1). Moreover, unlike the CuSO₄ algaecide, Cu-BDC MOF chips did not cause any acute toxicity (48 h) to the water flea Daphnia magna. Both Cu-BDC MOF and Cu₂O seemed to be responsible for the generation of reactive oxygen species, which resulted in the aggregation, photosynthesis disruption, and eventually growth inhibition of M. aeruginosa. This study suggests that the environmentally safe Cu-BDC MOF chip is a promising agent to sustainably control harmful algal blooms.

Biocompatibility of magnetic nanoparticles synthesized through green routed with a focus on hematological and histological analysis

The interaction of metal nanoparticles (MNPs) with blood cells and tissues is essential from the perspectives of biocompatibility and the production of novel drug delivery systems. In the present study, biosynthesized-Fe₃O₄ nanoparticles (bio-Fe₃O₄ NPs) were prepared and bio-modified using Daphne mucronata Royle leaf extracts. The physicochemical properties of bio-Fe₃O₄ NPs were determined using UV-Visible spectroscopy, Energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD), dynamic light scattering (DLS), and Fourier transform infrared (FT-IR) analyses. According to the SEM analysis, the bio-Fe₃O₄ NPs are spherical-shaped with a size range of 10-30 nm. Antibacterial effects of bio-Fe₃O₄ NPs against Staphylococcus aureus ATCC 43300 and Pseudomonas aeruginosa ATCC 27853 bacteria were measured by minimum inhibition/bactericidal concentrations (MIC and MBC tests). Result showed that the bio-Fe₃O₄ NPs (300 ppm) revealed highest antibacterial effect on S. aureus ATCC 43300. Also, bio-Fe₃O₄ NPs have different cell viability in the human breast cancer cell line (MCF-7) and mouse embryonic fibroblast (MEF). The interaction of bio-Fe₃O₄ NPs with blood cells and the complete blood count (CBC) factor illustrated that the morphology of blood cells and platelet clumping did not influence by nanoparticles. Furthermore, histological analysis of the liver, spleen, and kidney did not show any abnormality upon exposure to 100 mg kg^-1 bio-Fe₃O₄ NPs treated samples. Hence, the biosynthesized Fe₃O₄ NPs are a good candidate for applications in medical fields.

Barium hexaferrite nanoplatelets with polyphenol coatings for versatile applications as a stable, magnetic, and antimicrobial colloid

Colloidal stabilization of magnetic nanoparticles is one of the most important steps in the preparation of magnetic nanoparticles for potential biomedical applications. A special kind of magnetic nanoparticle are barium hexaferrite nanoplatelets (BSHF NPLs) with a hexagonal shape and a permanent magnetic moment. One strategy for the stabilization of BHF in aqueous media is to use coatings. In our research, we used an eco-friendly tannic acid, as a coating on BSHF NPLs. As-prepared BSHF NPLs coated with tannic acid were examined with transmission electron microscopy, infrared and UV-Vis spectroscopy, electro-kinetic measurements, and their room-temperature magnetic properties were measured. Stable colloids were tested in two biological complex media and antimicrobial properties of the material were examined. To enhance the antimicrobial properties of our material, we used tannic acid as a platform for the in-situ production of silver on BSHF NPLs. New hybrid material with silver also possesses magnetic properties and excellent antimicrobial activity against Escherichia coli and Staphylococcus aureus.