Antibacterial Mechanisms of Zinc Oxide Nanoparticle against Bacterial Food Pathogens Resistant to Beta-Lactam Antibiotics

Green Synthesis of Zinc Oxide Nanoparticles: Preparation, Characterization, and Biomedical Applications - A Review

Over the last decade, biomedical nanomaterials have garnered significant attention due to their remarkable biological properties and diverse applications in biomedicine. Metal oxide nanoparticles (NPs) are particularly notable for their wide range of medicinal uses, including antibacterial, anticancer, biosensing, cell imaging, and drug/gene delivery. Among these, zinc oxide (ZnO) NPs stand out for their versatility and effectiveness. Recently, ZnO NPs have become a primary material in various sectors, such as pharmaceutical, cosmetic, antimicrobials, construction, textile, and automotive industries. ZnO NPs can generate reactive oxygen species and induce cellular apoptosis, thus underpinning their potent anticancer and antibacterial properties. To meet the growing demand, numerous synthetic approaches have been developed to produce ZnO NPs. However, traditional manufacturing processes often involve significant economic and environmental costs, prompting a search for more sustainable alternatives. Intriguingly, biological synthesis methods utilizing plants, plant extracts, or microorganisms have emerged as ideal for producing ZnO NPs. These green production techniques offer numerous medicinal, economic, environmental, and health benefits. This review highlights the latest advancements in the green synthesis of ZnO NPs and their biomedical applications, showcasing their potential to revolutionize the field with eco-friendly and cost-effective solutions.

Synthesis, Characterization, and Evaluation of the Antimicrobial and Anticancer Activities of Zinc Oxide and Aluminum-Doped Zinc Oxide Nanocomposites

In this research, we developed undoped and aluminum-doped zinc oxide for antimicrobial and anticancer activities. This study focuses on the synthesis, characterization, and biological activities of zinc oxide nanoparticles (ZnO NPs) and aluminum-doped zinc oxide nanocomposites (Zn1-xAlxO NCs) at varying concentrations (x = 0, 0.25, 0.5, and 0.75 wt%) using the coprecipitation method. Various characterization techniques such as XRD, UV-Vis, FTIR, EDX, and SEM were performed to analyze the crystal structure, optical properties, functional group identification, elemental composition, and surface morphology. The antimicrobial activity test showed that Zn0.75Al0.25O NCs exhibited the strongest inhibition zone against Bacillus cereus compared to Staphylococcus aureus > Pasteurella multocida > Escherichia coli. Moreover, the cytotoxicity and cell viability of liver cancer (HepG-2), breast cancer (MCF-7), ovarian cancer (SKOV3), and normal liver cell lines) were evaluated using the MTT assay, demonstrating that Zn0.75Al0.25O NCs not only enhance cell destruction but also show low cytotoxicity and high biocompatibility at low concentrations. These results suggest that Zn0.75Al0.25O NCs could be a promising candidate for in vivo anticancer applications and should be further investigated.

Impact of a Functional Dairy Powder and Its Primary Component on the Growth of Pathogenic and Probiotic Gut Bacteria and Human Coronavirus 229E

Milk boasts an array of potent bioactive compounds, such as lactoferrin (Lf), immunoglobulins, and functional proteins, all delivering substantial therapeutic benefits. In this study, Immune Powder (a functional dairy formulation) and its primary component called Fractionated Milk Protein (FMP) containing Lf, zinc, and immunoglobulins and formulated by Ausnutria Pty Ltd. were evaluated for their potential broad-spectrum pharmacological activity. In particular, this study investigated the antibacterial (against pathogenic Escherichia coli), prebiotic (promoting Lactobacillus delbrueckii growth), anti-inflammatory (inhibition of NO production in RAW264.7 macrophages), and antiviral (against human coronavirus 229E) effects of the samples. In addition, the impact of simulated gastric digestion on the efficacy of the samples was explored. LCMS-based proteomics was implemented to unveil cellular and molecular mechanisms underlying antiviral activity. The Immune Powder demonstrated antibacterial activity against E. coli (up to 99.74 ± 11.47% inhibition), coupled with prebiotic action (10.84 ± 2.2 viability fold-change), albeit these activities diminished post-digestion (p < 0.01). The Immune Powder effectively mitigated NO production in lipopolysaccharide-stimulated RAW264.7 macrophages, with declining efficacy post-digestion (p < 0.0001). The Immune Powder showed similar antiviral activity before and after digestion (p > 0.05) with up to 3-fold improvement. Likewise, FMP exhibited antibacterial potency pre-digestion at high concentrations (95.56 ± 1.23% inhibition at 125 mg/mL) and post-digestion at lower doses (61.82 ± 5.58% inhibition at 3906.25 µg/mL). FMP also showed enhanced prebiotic activity post-digestion (p < 0.0001), NO inhibition pre-digestion, and significant antiviral activity. The proteomics study suggested that the formulation and its primary component shared similar antiviral mechanisms by inhibiting scavenger receptor binding and extracellular matrix interaction.

Fabrication of multifunctional ZnO@tannic acid nanoparticles embedded in chitosan and polyvinyl alcohol blend packaging film

The current study explores biodegradable packaging materials that have high food quality assurance, as food deterioration is mostly caused by UV degradation and oxidation, which can result in bad flavor and nutrition shortages. Thus, new multifunctional zinc oxide nanoparticles/tannic acid (ZnO@TA) with antioxidant and antibacterial activities were incorporated into polyvinyl alcohol/chitosan (PVA/CH) composite films with different ratios (1%, 3%, and 5% based on the total dry weight of the film) via a solution blending method in a neutral aqueous solution. Additionally, ZnO nanoparticles have unique antibacterial mechanisms through the generation of excessive reactive oxygen species (ROS) that may lead to intensify pathogen resistance to conventional antibacterial agents. Thus, minimizing the negative effects caused by excessive levels of ROS may be possible by developing unique, multifunctional ZnO nanoparticles with antioxidant potential via coordination bond between tannic acid and ZnO nanoparticles (ZnO@TA). ZnO@TA nanoparticles were examined using Fourier-transform infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The effect of the incorporation of ZnO@TA nanoparticles on the barrier, mechanical, thermal, antioxidant, antimicrobial, and UV blocking characteristics of chitosan/polyvinyl alcohol (ZnO@TA@CH/PVA) films was investigated. The lowest water vapor and oxygen permeability and the maximum antioxidant capacity% are 31.98 ± 1.68 g mm/m2 kPa day, 0.144 ± 5.03 × 10-2 c.c/m2.day, and 69.35 ± 1.6%, respectively, which are related to ZnO@TA(50)@CH/PVA. Furthermore, ZnO@TA(50)@CH/PVA film exhibits the maximum UV shielding capacity of UVB (99.994). ZnO@TA(50) @PVA/CH films displayed better tensile strength and Young`s modulus of 48.72 ± 0.23 MPa and 2163.46 ± 61.4 MPa, respectively, than the other film formulations. However, elongation % at break exhibited the most reduced value of 19.62 ± 2.3%. ZnO@TA@CH/PVA film exhibits the largest inhibition zones of 11 ± 1.0, 12.3 ± 0.57, and 13.6 ± 0.57 mm against Staphylococcus aureus, Aspergillus flavus, and Candida albicans, respectively. In accordance with these results, ZnO@TA@CH/PVA films could be utilized for food preservation for the long-term.

Inhibition of the Growth of Escherichia coli and Staphylococcus aureus Microorganisms in Aesthetic Orthodontic Brackets through the In Situ Synthesis of Ag, TiO2 and Ag/TiO2 Nanoparticles

Plaque control is especially important during orthodontic treatment because areas of the teeth near brackets and wires are difficult to clean with a toothbrush, resulting in debris buildup of food or dental plaque, thus causing caries and periodontal disease. The objective of this study was to evaluate the antimicrobial properties of silver nanoparticles (AgNPs), titanium dioxide nanoparticles (TiO2NPs), and silver/titanium dioxide nanoparticles (Ag/TiO2NPs), synthesized on the surface of α-alumina ceramic brackets. The AgNPs and TiO2NPs were synthesized by a simple chemical method, and these were characterized by XRD, SEM, and XPS TEM; the antimicrobial activity was tested against Staphylococcus aureus and Escherichia coli by diffusion test. The results of this study demonstrated that by this simple chemical method, silver and titanium dioxide nanoparticles can be synthesized on the surface of α-alumina esthetic brackets, and these NPs possess good antimicrobial activity and the possibility of reducing dental caries, periodontal disease, and white spot generated during orthodontic treatment.

Comparative effects of dietary zinc nanoparticle and conventional zinc supplementation on broiler chickens: A meta-analysis

Background and Aim

Zinc (Zn) is important for various physiological processes in broiler chickens, including protein and carbohydrate metabolism, growth, and reproduction. The gastrointestinal absorption of Zn in broiler chickens was notably low. One approach that has been explored for enhancing the bioavailability of Zn is the development of Zn nanoparticles (NPs). Zn is required for various physiological processes in broiler chickens, including protein and carbohydrate metabolism, growth, and reproduction. Therefore, this study aimed to assess the impact of conventional Zn and Zn NPs on broiler chickens using a meta-analysis methodology.

Materials and Methods

A database was built from published literature to evaluate the effects of the addition of Zn NPs and conventional Zn on broiler chicken responses, including the following parameters: production performance; carcass cuts; visceral organ weight; lymphoid organ weight; nutrient digestibility; intestinal villi; mineral Zn, calcium, and phosphorus concentrations; hematology; blood parameters; immunoglobulin; and intestinal bacterial population. Various scientific platforms, including Scopus, Web of Science, PubMed Central, and Google Scholar, were used to search for peer-reviewed articles. A database was created from 25 studies that met the inclusion criteria. The data were then processed for a meta-analysis using a mixed-model methodology. Different types of Zn (NPs versus conventional) were considered fixed effects, different studies were treated as random effects, and p-values were used as model statistics.

Results

Across the parameters observed in this study, the use of Zn NPs was more efficient in Zn utilization than conventional Zn, as evidenced by the average dose of Zn NPs being much lower than that of conventional Zn (79.44 vs. 242.76 mg/kg) yet providing similar (p > 0.05) or even significantly better effects (p < 0.05) compared to conventional Zn usage.

Conclusion

This investigation revealed the beneficial influence of Zn NPs in broiler chickens compared to the conventional utilization of Zn through an all-encompassing meta-analysis. Moreover, Zn NPs have proven to be more effective in Zn utilization when juxtaposed with conventional Zn, as demonstrated by the significantly lower quantity of Zn NPs administered compared to conventional Zn, while yielding comparable or even superior outcomes compared to the traditional utilization of Zn. A limitation of this study is that the Zn NPs used were sourced from inorganic Zn NPs. Therefore, future research should focus on evaluating the efficiency of organic Zn NPs in broiler chicken feed.

Differential Impact of Zinc Salt Precursors on Physiognomies, Anticancerous, and Antibacterial Activities of Zinc Oxide Nanoparticles

Zinc oxide nanoparticles (ZnONPs) are enormously popular semi-conductor metal oxides with diverse applications in every field of science. Many physical and chemical methods applied for the synthesis of ZnONPs are being rejected due to their environmental hazards. Therefore, ZnONPs synthesized from plant extracts are steered as eco-friendly showing more biocompatibility and biodegradability. Additionally, various synthesis conditions such as the type of precursor salt also play a role in influencing the physicochemical and biological properties of ZnONPs. In this study, green synthesis of ZnONPs from Acacia nilotica was carried out using zinc acetate (ZA-AN-ZNPs), zinc nitrate (ZN-AN-ZNPs), and zinc sulfate (ZS-AN-ZNPs) precursor salts. Surprisingly, characterization of ZnONPs using UV-visible spectroscopy, TEM, XRD, and EDX revealed the important role precursor salts played in influencing the size and shape of ZnONPs, i.e., 20-23 nm spherical (ZA-AN-ZNPs), 55-59 nm triangular (ZN-AN-ZNPs), and 94-97 nm nano-flowers (ZS-AN-ZNPs). FTIR analysis showed the involvement of alkaloids, alcohols, carboxylic acid, and phenolic compounds present in Acacia nilotica extract during the synthesis process. Since different precursor salts showed different morphology of ZnONPs, their biological activities were also variable. ZN-AN-ZNPs showed the highest cytotoxicity towards HepG2 cells with the lowest cell viability (28.92 ± 0.99%), highest ROS/RNS production (3425.3 ± 184.58 relative DHR123 fluorescence), and loss of mitochondrial membrane potential (1645.2 ± 32.12 relative fluorescence unit) as well as induced significant caspase-3 gene expression. In addition to this, studying the zone of inhibitions and minimum bactericidal and inhibitory concentrations of ZnONPs showed their exceptional potential as antibacterial agents. At MIC as low as 8 µg/mL, ZA-AN-ZNPs and ZN-AN-ZNPs exhibited significant bactericidal activities against human pathogens Klebsiella pneumoniae and Listeria monocytogenes, respectively. Furthermore, alkaline phosphatase, DNA/RNA leakage, and phosphate ion leakage studies revealed that a damage to the bacterial cell membrane and cell wall is involved in mediating the antibacterial effects of ZnONPs.

Microleakage Assessment of Modified Resin Infiltration With Zinc Oxide (ZnO) and Magnesium Oxide (MgO) Nanoparticles on Artificial Enamel Caries Lesion: An In Vitro Study

Background Incorporating nanoparticles into resin infiltrant (RI) can alter its physical properties, including microleakage. This study aimed to examine the microleakage properties of RI modified with 2.5% and 5% zinc oxide (ZnO) and magnesium oxide (MgO) nanoparticles on artificially induced carious lesions (ACLs) in bovine teeth. Materials and methods Modified RIs were applied to five sound and 30 ACLs on bovine incisors. They were divided into seven groups based on the procedure (Group 1: sound enamel (SE), Group 2: artificial caries lesion only (ACL), Group 3: RI, Group 4: RI+ 2.5% ZnO, Group 5: RI + 5% ZnO, Group 6: RI + 2.5% MgO, Group 7: RI + 5% MgO). The samples were subjected to 5000 thermal cycles and then exposed to methylene blue solution for 24 hours in an incubator. The teeth were sectioned and examined with a stereomicroscope to assess the depth of methylene blue penetration (MBP), quantifying microleakage according to the following scoring: 0 = no penetration, 1 = outer half of enamel, 2 = inner half of enamel, 3 = outer half of dentin, and 4 = inner half of dentin. An ANOVA test was conducted to assess the significance of differences among the groups. Post-hoc tests, including Tukey's HSD (honestly significant difference) test, were performed to identify specific group differences and determine which differences were statistically significant. Results SE samples (Group 1) showed minimal penetration, with 100% scoring 1, indicating high resistance to MBP. The ACL group had significant penetration, with 77.78% scoring 3 and 22.22% scoring 2. The RI group completely prevented MBP, with all samples scoring 0. Both RI+2.5% ZnO (Group 4) and RI+2.5% MgO (Group 6) were highly effective, with 88.89% scoring 0 and 11.11% scoring 1. RI+5% ZnO (Group 5) and RI+5% MgO (Group 7) also prevented MBP but had slightly higher minimal penetration, with 77.78% scoring 0 and 22.22% scoring 1. Significant differences were observed between the ACL group and all other groups, underscoring the effectiveness of RI treatments. No significant differences were found between RI+ZnO and RI+MgO at both concentrations, indicating similar effectiveness. Conclusions The study demonstrated that RI modified with 2.5% and 5% ZnO and MgO nanoparticles effectively reduced microleakage in ACLs on bovine teeth compared to untreated lesions. These modifications significantly inhibited MBP, particularly in enamel and dentin, indicating their potential to enhance the durability and effectiveness in clinical applications. This research emphasizes the promising role of nanoparticle-modified RI in minimizing microleakage and optimizing treatment outcomes. Further research is needed to confirm these findings and refine protocols.

Enhanced bactericidal, antibiofilm and antioxidative response of Lawsonia inermis leaf extract synthesized ZnO NPs loaded with commercial antibiotic

Globally, antibiotic resistance is a challenging issue in healthcare sector. The emergence of multiple drug-resistant bacteria has forced us to modify existing medicines and or formulate newer medicines that are effective and inexpensive. In this perspective, this study involves the formation of zinc oxide nanoparticles (ZnO NPs) by utilizing the Lawsonia inermis (Li) leaf extract. The prepared L. inermis leaf extract mediated ZnO NPs (Li-ZnO NPs) were bio-physically characterized. The antibacterial and radical scavenging effects of Li-ZnO NPs were evaluated. In addition, ZnO NPs were conjugated with standard antibiotic (ciprofloxacin) and its drug loading efficiency, drug release and antibacterial efficacy were tested and compared with non-drug loaded ZnO NPs. An absorbance peak at 340 nm was noted for Li-ZnO NPs. After conjugation with the drug, two absorbance peaks- one at 242 nm characteristic of ciprofloxacin and the other at 350 nm characteristics of ZnO NPs were observed. The crystallite size was 18.7 nm as determined by XRD. The antibacterial effect was higher on Gram-positive (S. aureus and S. pyogenes) than the Gram-negative pathogens (E. coli and K. pneumoniae). Inhibition of S. aureus and S. pyogenes biofilm at 100 μg mL-1were, respectively, 97.5 and 92.6%. H2O2 free radicals was inhibited to 90% compared to the standard ascorbic acid at 100 μg mL-1. After drug loading, the FTIR spectrum confirmed the existence of ciprofloxacin peaks at 965 cm-1 and Zn-O bond at 492 cm-1. The drug loading capacity of 15 nm sized ZnO NPs was higher (58, 75, 90 and 95% at 1, 2.5, 5 and 10% drug concentrations, respectively) compared to 20 nm. Similarly, the percentage of drug (ciprofloxacin) released from 15 nm ZnO NPs were increased to 90% at 10% drug-loaded samples, respectively. Also, the antibiotic loaded ZnO NPs had significant antibacterial effects against tested bacteria compared to Li-ZnO NPs and ciprofloxacin alone. This revealed that the antibiotic loaded ZnO NPs offer a sustainable route to treat multi-drug-resistant bacterial infections.

Cutting-edge developments in zinc oxide nanoparticles: synthesis and applications for enhanced antimicrobial and UV protection in healthcare solutions

This paper presents a comprehensive review of recent advancements in utilizing zinc oxide nanoparticles (ZnO NPs) to enhance antimicrobial and UV protective properties in healthcare solutions. It delves into the synthesis techniques of ZnO NPs and elucidates their antimicrobial efficacy, exploring the underlying mechanisms governing their action against a spectrum of pathogens. Factors impacting the antimicrobial performance of ZnO NPs, including size, surface characteristics, and environmental variables, are extensively analyzed. Moreover, recent studies showcasing the effectiveness of ZnO NPs against diverse pathogens are critically examined, underscoring their potential utility in combatting microbial infections. The study further investigates the UV protective capabilities of ZnO NPs, elucidating the mechanisms by which they offer UV protection and reviewing recent innovations in leveraging them for UV-blocking applications in healthcare. It also dissects the factors influencing the UV shielding performance of ZnO NPs, such as particle size, dispersion quality, and surface coatings. Additionally, the paper addresses challenges associated with integrating ZnO NPs into healthcare products and presents future perspectives for overcoming these hurdles. It emphasizes the imperative for continued research efforts and collaborative initiatives to fully harness the potential of ZnO NPs in developing advanced healthcare solutions with augmented antimicrobial and UV protective attributes. By advancing our understanding and leveraging innovative approaches, ZnO NPs hold promise for addressing pressing healthcare needs and enhancing patient care outcomes.

Synthesis and characterization of Pyrus communis fruit extract synthesized ZnO NPs and assessed their anti-diabetic and anti-microbial potential

The fruit Pyrus communis, owing to its presence of phenolics and flavonoids, was chosen for its nanoparticle's reducing and stabilizing properties. Furthermore, the zinc metal may be nano-absorbed by the human body. As a result, the study involves synthesizing zinc oxide nanoparticles (ZnO NPs) from P. communis fruit extract using the green method. The synthesized nanoparticle was examined with a UV-visible spectrophotometer, Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Dynamic Light Scattering (DLS). When absorption studies were performed with a UV-visible spectrophotometer, the nanoparticle exhibited a blue shift. The FTIR spectrum revealed the molecular groups present in both the fruit extract and metal. In the SEM analysis, the ZnO NPs appeared as spherical particles, agglomerated together, and of nano-size. The larger size of the ZnO NPs in DLS can be attributed to their ability to absorb water. After characterization, nanoparticles were tested for anti-diabetic (α-amylase and yeast glucose uptake activity) and anti-microbial properties. The α-amylase inhibition percentage was 46.46 ± 0.15% for 100 μg/mL, which was comparable to the acarbose inhibition percentage of 50.58 ± 0.67% at the same concentration. The yeast glucose uptake activity was 64.24 ± 0.80% at 20 mM glucose concentration, which was comparable to the standard of 78.03 ± 0.80. The nanoparticle was more effective against Gram-negative bacteria Shigella sp. and Salmonella typhi than against Gram-positive bacteria Bacillus cereus and Streptococcus pneumoniae.

Recent advancements in natural polymers-based self-healing nano-materials for wound dressing

The field of wound healing has witnessed remarkable progress in recent years, driven by the pursuit of advanced wound dressings. Traditional dressing materials have limitations like poor biocompatibility, nonbiodegradability, inadequate moisture management, poor breathability, lack of inherent therapeutic properties, and environmental impacts. There is a compelling demand for innovative solutions to transcend the constraints of conventional dressing materials for optimal wound care. In this extensive review, the therapeutic potential of natural polymers as the foundation for the development of self-healing nano-materials, specifically for wound dressing applications, has been elucidated. Natural polymers offer a multitude of advantages, possessing exceptional biocompatibility, biodegradability, and bioactivity. The intricate engineering strategies employed to fabricate these polymers into nanostructures, thereby imparting enhanced mechanical robustness, flexibility, critical for efficacious wound management has been expounded. By harnessing the inherent properties of natural polymers, including chitosan, alginate, collagen, hyaluronic acid, and so on, and integrating the concept of self-healing materials, a comprehensive overview of the cutting-edge research in this emerging field is presented in the review. Furthermore, the inherent self-healing attributes of these materials, wherein they exhibit innate capabilities to autonomously rectify any damage or disruption upon exposure to moisture or body fluids, reducing frequent dressing replacements have also been explored. This review consolidates the existing knowledge landscape, accentuating the benefits and challenges associated with these pioneering materials while concurrently paving the way for future investigations and translational applications in the realm of wound healing.

Photocatalytic degradation of antibiotics and antimicrobial and anticancer activities of two-dimensional ZnO nanosheets

Active pharmaceutical ingredients have emerged as an environmentally undesirable element because of their widespread exploitation and consequent pollution, which has deleterious effects on living things. In the pursuit of sustainable environmental remediation, biomedical applications, and energy production, there has been a significant focus on two-dimensional materials (2D materials) owing to their unique electrical, optical, and structural properties. Herein, we have synthesized 2D zinc oxide nanosheets (ZnO NSs) using a facile and practicable hydrothermal method and characterized them thoroughly using spectroscopic and microscopic techniques. The 2D nanosheets are used as an efficient photocatalyst for antibiotic (herein, end-user ciprofloxacin (CIP) was used as a model antibiotic) degradation under sunlight. It is observed that ZnO NSs photodegrade ~ 90% of CIP within two hours of sunlight illumination. The molecular mechanism of CIP degradation is proposed based on ex-situ IR analysis. Moreover, the 2D ZNO NSs are used as an antimicrobial agent and exhibit antibacterial qualities against a range of bacterial species, including Escherichia coli, Staphylococcus aureus, and MIC of the bacteria are found to be 5 μg/l and 10 μg/l, respectively. Despite having the biocompatible nature of ZnO, as-synthesized nanosheets have also shown cytotoxicity against two types of cancer cells, i.e. A549 and A375. Thus, ZnO nanosheets showed a nontoxic nature, which can be exploited as promising alternatives in different biomedical applications.

Effects of Zinc Oxide Nanoparticles Supplementation on Growth Performance, Meat Quality and Serum Biochemical Parameters in Broiler Chicks

The zinc oxide nanoparticles (ZnONPs) have attracted exhilarating research interest due to their novel distinguishing characteristics such as size, shape, high surface activity, large surface area and biocompatibility. Being highly bioavailable and exerting a superior efficacy than conventional zinc sources, ZnONPs is emerging as an alternative feed supplement for poultry. The present study involves the synthesis of ZnONPs through a cost effective and eco-friendly method using planetary ball milling technique and characterized for its size, shape, optical property, functional group and elemental concentration using particle size analyzer, Transmission Electron Microscopy, X-Ray Diffraction analysis, Fourier Transform Infra-Red spectroscopy, UV-Vis spectroscopy and Inductively Coupled Plasma-Mass Spectroscopy. In vitro cytotoxicity study using Baby Hamster kidney (BHK-21) cells, Vero cells and primary chick liver culture cells revealed that ZnONPs can be safely incorporated in the broiler chick's feed up to the concentration of 100 mg/kg. To investigate the effects of ZnONPs on production performances in broiler chicks, a feeding trial was carried out using 150-day-old broiler chicks randomly allotted in five treatment groups. The dietary treatment groups were: T1 (80 mg/kg of zinc oxide), T2 (60 mg/kg of zinc methionine) and T3, T4 and T5 received 60, 40 and 20 mg/kg of ZnONPs respectively. The results showed a significant improvement (p < 0.05) in the body weight gain and feed conversion ratio of broiler chicks supplemented with 20 and 40 mg/kg of ZnONPs. The ZnONPs supplementation significantly (p < 0.05) increased the dressing percentage in addition to significant (p < 0.05) reduction in the meat pH compared to inorganic and organic zinc supplementation. Overall, an eco-friendly method for ZnONPs synthesis was demonstrated and the optimum dietary level (20 mg/kg) of ZnONPs could enhance the growth, the meat quality and Zn uptake without any negative effects on selected serum biochemical parameters in the broiler chicks.

Metal-based nanoparticles in antibacterial application in biomedical field: Current development and potential mechanisms

The rise in drug resistance in pathogenic bacteria greatly endangers public health in the post-antibiotic era, and drug-resistant bacteria currently pose a great challenge not only to the community but also to clinical procedures, including surgery, stent implantation, organ transplantation, and other medical procedures involving any open wound and compromised human immunity. Biofilm-associated drug failure, as well as rapid resistance to last-resort antibiotics, necessitates the search for novel treatments against bacterial infection. In recent years, the flourishing development of nanotechnology has provided new insights for exploiting promising alternative therapeutics for drug-resistant bacteria. Metallic agents have been applied in antibacterial usage for several centuries, and the functional modification of metal-based biomaterials using nanotechnology has now attracted great interest in the antibacterial field, not only for their intrinsic antibacterial nature but also for their ready on-demand functionalization and enhanced interaction with bacteria, rendering them with good potential in further translation. However, the possible toxicity of MNPs to the host cells and tissue still hinders its application, and current knowledge on their interaction with cellular pathways is not enough. This review will focus on recent advances in developing metallic nanoparticles (MNPs), including silver, gold, copper, and other metallic nanoparticles, for antibacterial applications, and their potential mechanisms of interaction with pathogenic bacteria as well as hosts.

Osteoblast Attachment on Bioactive Glass Air Particle Abrasion-Induced Calcium Phosphate Coating

Air particle abrasion (APA) using bioactive glass (BG) effectively decontaminates titanium (Ti) surface biofilms and the retained glass particles on the abraded surfaces impart potent antibacterial properties against various clinically significant pathogens. The objective of this study was to investigate the effect of BG APA and simulated body fluid (SBF) immersion of sandblasted and acid-etched (SA) Ti surfaces on osteoblast cell viability. Another goal was to study the antibacterial effect against Streptococcus mutans. Square-shaped 10 mm diameter Ti substrates (n = 136) were SA by grit blasting with aluminum oxide particles, then acid-etching in an HCl-H2SO4 mixture. The SA substrates (n = 68) were used as non-coated controls (NC-SA). The test group (n = 68) was further subjected to APA using experimental zinc-containing BG (Zn4) and then mineralized in SBF for 14 d (Zn4-CaP). Surface roughness, contact angle, and surface free energy (SFE) were calculated on test and control surfaces. In addition, the topography and chemistry of substrate surfaces were also characterized. Osteoblastic cell viability and focal adhesion were also evaluated and compared to glass slides as an additional control. The antibacterial effect of Zn4-CaP was also assessed against S. mutans. After immersion in SBF, a mineralized zinc-containing Ca-P coating was formed on the SA substrates. The Zn4-CaP coating resulted in a significantly lower Ra surface roughness value (2.565 μm; p < 0.001), higher wettability (13.35°; p < 0.001), and higher total SFE (71.13; p < 0.001) compared to 3.695 μm, 77.19° and 40.43 for the NC-SA, respectively. APA using Zn4 can produce a zinc-containing calcium phosphate coating that demonstrates osteoblast cell viability and focal adhesion comparable to that on NC-SA or glass slides. Nevertheless, the coating had no antibacterial effect against S. mutans.

Rare post-operative intracranial abscess due to Serratia marcescens: what we can learn from it?

BACKGROUND

Nosocomial infections caused by Serratia marcescens mostly occurred in pediatrics and it was very rarely reported after adult surgery. Here, an intracranial abscess caused by Serratia marcescens was reported. We report a rare case of a postoperative intracranial abscess caused by Serratia marcescens in a 63-year-old male patient with a left parietal mass. The patient underwent resection of the mass on June 1, 2022, and the postoperative pathology revealed an angiomatous meningioma, WHO I. He then experienced recurrent worsening of right limb movements, and repeated cranial CT scans showed oozing blood and obvious low-density shadows around the operation area. Delayed wound healing was considered. Subsequently, a large amount of pus was extracted from the wound. The etiological test showed that Serratia marcescens infection occurred before the removal of the artificial titanium mesh. Antibiotics were initiated based on the results of drug susceptibility tests. At present, the patient is recovering well and is still closely monitored during follow-up.

CONCLUSION

It is rare for Serratia marcescens to cause brain abscesses without any obvious signs of infection. This report provided in detail our experience of a warning postoperative asymptomatic brain abscess caused by an uncommon pathogen.

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.

Peelable Alginate Films Reinforced by Carbon Nanofibers Decorated with Antimicrobial Nanoparticles for Immediate Biological Decontamination of Surfaces

This study presents the synthesis and characterization of alginate-based nanocomposite peelable films, reinforced by carbon nanofibers (CNFs) decorated with nanoparticles that possess remarkable antimicrobial properties. These materials are suitable for immediate decontamination applications, being designed as fluid formulations that can be applied on contaminated surfaces, and subsequently, they can rapidly form a peelable film via divalent ion crosslinking and can be easily peeled and disposed of. Silver, copper, and zinc oxide nanoparticles (NPs) were synthesized using superficial oxidized carbon nanofibers (CNF-ox) as support. To obtain the decontaminating formulations, sodium alginate (ALG) was further incorporated into the colloidal solutions containing the antimicrobial nanoparticles. The properties of the initial CNF-ox-NP-ALG solutions and the resulting peelable nanocomposite hydrogels (obtained by crosslinking with zinc acetate) were assessed by rheological measurements, and mechanical investigations, respectively. The evaluation of Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) for the synthesized nanoparticles (silver, copper, and zinc oxide) was performed. The best values for MIC and MBC were obtained for CNF-ox decorated with AgNPs for both types of bacterial strains: Gram-negative (MIC and MBC values (mg/L): E. coli-3 and 108; P. aeruginosa-3 and 54) and Gram-positive (MIC and MBC values (mg/L): S. aureus-13 and 27). The film-forming decontaminating formulations were also subjected to a microbiology assay consisting of the time-kill test, MIC and MBC estimations, and evaluation of the efficacity of peelable coatings in removing the biological agents from the contaminated surfaces. The best decontamination efficiencies against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa varied between 97.40% and 99.95% when employing silver-decorated CNF-ox in the decontaminating formulations. These results reveal an enhanced antimicrobial activity brought about by the synergistic effect of silver and CNF-ox, coupled with an efficient incorporation of the contaminants inside the peelable films.

Fabrication of Antibacterial and Antioxidant ZnO-Impregnated Amine-Functionalized Chitosan Bio-Nanocomposite Membrane for Advanced Biomedical Applications

Developing a variety of safe and effective functioning wound dressings is a never-ending objective. Due to their exceptional antibacterial activity, biocompatibility, biodegradability, and healing-promoting properties, functionalized chitosan nanocomposites have attracted considerable attention in wound dressing applications. Herein, a novel bio-nanocomposite membrane with a variety of bio-characteristics was created through the incorporation of zinc oxide nanoparticles (ZnONPs) into amine-functionalized chitosan membrane (Am-CS). The developed ZnO@Am-CS bio-nanocomposite membrane was characterized by various analysis tools. Compared to pristine Am-CS, the developed ZnO@Am-CS membrane revealed higher water uptake and adequate mechanical properties. Moreover, increasing the ZnONP content from 0.025 to 0.1% had a positive impact on antibacterial activity against Gram-positive and Gram-negative bacteria. A maximum inhibition of 89.4% was recorded against Escherichia coli, with a maximum inhibition zone of 38 ± 0.17 mm, and was achieved by the ZnO (0.1%)@Am-CS membrane compared to 72.5% and 28 ± 0.23 mm achieved by the native Am-CS membrane. Furthermore, the bio-nanocomposite membrane demonstrated acceptable antioxidant activity, with a maximum radical scavenging value of 46%. In addition, the bio-nanocomposite membrane showed better biocompatibility and reliable biodegradability, while the cytotoxicity assessment emphasized its safety towards normal cells, with the cell viability reaching 95.7%, suggesting its potential use for advanced wound dressing applications.

Zingiber officinale rhizome extracts mediated ni nanoparticles and its promising biomedical and environmental applications

BACKGROUND

Zingiber officinale, generally known as ginger, contains bioactive phytochemicals, including gingerols and shogaols, that may function as reducing agents and stabilizers for the formation of nickel nanoparticles (Ni-NPs). Ginger extract-mediated nickel nanoparticles were synthesized using an eco-friendly method, and their antibacterial, antioxidant, antiparasitic, antidiabetic, anticancer, dye degrading, and biocompatibility properties were investigated.

METHODS

UV-visible spectroscopy, fourier transform infrared spectroscopy, X-ray powder diffraction, energy-dispersive X-ray spectroscopy, and scanning electron microscopy were used to validate and characterize the synthesis of Ni-NPs. Agar well diffusion assay, alpha-amylase and glucosidase inhibitory assay, free radical scavenging assay, biocompatibility assay, and MTT assay were used to analyse the biomedical importance of Ni-NPs.

RESULTS

SEM micrograph examinations revealed almost aggregates of Ni-NPs; certain particles were monodispersed and spherical, with an average grain size of 74.85 ± 2.5 nm. Ni-NPs have successfully inhibited the growth of Pseudomonas aeruginosa, Escherichia coli, and Proteus vulgaris by inducing membrane damage, as shown by the absorbance at 260 nm (A260). DPPH (2,2-diphenyl-1-picrylhydrazyl) free radicals were successfully scavenged by Ni-NPs at an inhibition rate of 69.35 ± 0.81% at 800 µg/mL. A dose-dependent cytotoxicity of Ni-NPs was observed against amastigote and promastigote forms of Leishmania tropica, with significant mortality rates of 94.23 ± 1.10 and 92.27 ± 1.20% at 1.0 mg/mL, respectively. Biocompatibility studies revealed the biosafe nature of Ni-NPs by showing RBC hemolysis up to 1.53 ± 0.81% at 400 µg/mL, which is considered safe according to the American Society for Materials and Testing (ASTM). Furthermore, Ni-NPs showed antidiabetic activity by inhibiting α-amylase and α-glucosidase enzymes at an inhibition rate of 22.70 ± 0.16% and 31.23 ± 0.64% at 200 µg/mL, respectively. Ni-NPs have shown significant cytotoxic activity by inhibiting MCF-7 cancerous cells up to 68.82 ± 1.82% at a concentration of 400 µg/mL. The IC50 for Ni-NPs was almost 190 µg/mL. Ni-NPs also degraded crystal violet dye up to 86.1% at 2 h of exposure.

CONCLUSIONS

In conclusion, Zingiber officinale extract was found successful in producing stable nanoparticles. Ni-NPs have shown substantial biomedical activities, and as a result, we believe these nanoparticles have potential as a powerful therapeutic agent for use in nanomedicine.

Zinc Oxide Nanoparticles Promise Anticancer and Antibacterial Activity in Ovarian Cancer

BACKGROUND

Ovarian cancer is the most lethal cancer in gynaecology. Surgery, chemotherapy, and radiotherapy are the most often used cancer-fighting strategies. Post-surgery infection is fairly prevalent, especially among people with insufficient immunity. Zinc oxide nanoparticles (ZnOnps) have amazing biomedical features as anticancer and antibacterial agents.

METHODS

We investigated the behaviour of ZnOnps synthesized by green methods on ovarian cancers using established human ovarian cancer cell lines, besides the antibacterial action toward models of gram + ve and gram -ve bacteria. The cytotoxic effect of ZnOnps was calculated using a Sulforhodamine B (SRB) trial. Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were tested as models for gram + ve and gram -ve bacteria. The selected bacteria were subjected to concentrations of 20, 40, 80, and 100 μg/ml.

RESULTS

The synthesized ZnOnps induced 50% inhibitory concentration (IC50) at a concentration of 27.45 μg/ml. The diameter of inhibition ranged between 20.16 ± 0.16 and 27 ± 0.57 mm for S. aureus and 25.66 ± 0.33 to 31 ± 0.33 mm for E. coli. ZnOnps antagonistic effect statistically differed with neomycin, cefaclor, and cefadroxil.

CONCLUSIONS

Green synthesis of ZnOnps is easily prepared, low cost, non-toxic, and eco-friendly. Their cytotoxic action on SKOV3 cells and their antibacterial characteristics pave the way to be an alternative therapy for ovarian cancer and S. aureus and E. coli infection.

Synergistic Anticandidal Effectiveness of Greenly Synthesized Zinc Oxide Nanoparticles with Antifungal Agents against Nosocomial Candidal Pathogens

The high prevalence of fungal resistance to antifungal drugs necessitates finding new antifungal combinations to boost the antifungal bioactivity of these agents. Hence, the aim of the present investigation was to greenly synthesize zinc oxide nanoparticles (ZnO-NPs) using an aqueous leaf extract of Salvia officinalis and investigate their antifungal activity and synergistic efficiency with common antifungal agents. The biofabricated ZnO-NPs were characterized to detect their physicochemical properties. A disk diffusion assay was employed to investigate the antifungal effectiveness of the greenly synthesized ZnO-NPs and evaluate their synergistic patterns with common antifungal agents. The Candida tropicalis strain was detected to be the most susceptible strain to ZnO-NPs at both tested concentrations of 50 and 100 µg/disk, demonstrating relative suppressive zones of 19.68 ± 0.32 and 23.17 ± 0.45 mm, respectively. The minimum inhibitory concentration (MIC) of ZnO-NPs against the C. tropicalis strain was 40 µg/mL, whereas the minimum fungicidal concentration (MFC) was found to be 80 µg/mL. The highest synergistic efficiency of the biogenic ZnO-NPs with terbinafine antifungal agent was detected against the C. glabrata strain, whereas the highest synergistic efficiency was detected with fluconazole against the C. albicans strain, demonstrating relative increases in fold of inhibition area (IFA) values of 6.82 and 1.63, respectively. Moreover, potential synergistic efficiency was detected with the nystatin antifungal agent against the C. tropicalis strain with a relative IFA value of 1.06. The scanning electron microscopy (SEM) analysis affirmed the morphological deformations of candidal cells treated with the biosynthesized ZnO-NPs as the formation of abnormal infoldings of the cell wall and membranes and also the formation of pores in the cell wall and membranes, which might lead to the leakage of intracellular constituents. In conclusion, the potential synergistic efficiency of the biogenic ZnO-NPs with terbinafine, nystatin, and fluconazole against the tested candidal strains highlights the potential application of these combinations in formulating novel antifungal agents of high antimicrobial efficiency. The biogenic ZnO nanoparticles and antifungal drugs exhibit powerful synergistic efficiency, which highlights their prospective use in the formulation of efficient antimicrobial medications, including mouthwash, ointments, lotions, and creams for effective candidiasis treatment.

In vitro Evaluation of Antibacterial Activity of Synthetic Zeolite Supported AgZno Nanoparticle Against a Selected Group of Bacteria

Background

The development of novel and intriguing nanoparticle (NP)-based materials with antibacterial activity has recently received attention due to the problem of bacterial resistance to conventional antibiotics becoming more and more frequent. Thus, this study aimed to investigate the antibacterial effectiveness of a synthetic zeolite-supported AgZnO nanoparticle against selected bacteria in vitro.

Methods

Using the disc diffusion method, the antibacterial activity of synthetic zeolite-supported AgZnO nanoparticles was assessed against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Zinc oxide (ZnO) and Ag/ZnO nanoparticles were used to create the zeolite-supported Ag/ZnO composite. Chloramphenicol was used as a standard drug. The nanoparticles and composites were characterized using powder X-ray diffraction (XRD), Fourier transform infrared (FTIR), and atomic absorption spectroscopy (AAS).

Results

Synthetic zeolite-supported AgZnO nanoparticles showed promising antibacterial properties with the largest zone of inhibition against S. aureus bacteria in comparison to E. coli. The synthetic zeolite-supported AgZnO nanoparticle displayed a zone of inhibition against S. aureus and E. coli without a remarkable difference compared to the respective standard drug (Chloramphenicol). Zinc peaks were visible in the X-ray diffractograms, which supported the theory that the characteristic hexagonal wurtzite structure of zinc oxide was present.

Conclusion

All types of ZnO, AgZnO, and AgZnO-Zeolite showed wide-spectrum activity with better effect against gram-positive bacteria, while the Zeolite-Ag/ZnO composite showed even better antibacterial activity. The findings suggest a potential bactericide that needs further evaluation in future studies was observed in synthetic zeolite-supported Ag/ZnO nanoparticles.

Synergistic Antibacterial Proficiency of Green Bioformulated Zinc Oxide Nanoparticles with Potential Fosfomycin Synergism against Nosocomial Bacterial Pathogens

The drug resistance of bacterial pathogens causes considerable morbidity and death globally, hence there is a crucial necessity for the development of effective antibacterial medicines to address the antibacterial resistance issue. The bioprepared zinc oxide nanoparticles (ZnO-NPs) were prepared utilizing the flower extract of Hibiscus sabdariffa and then characterized using different physicochemical techniques. The antibacterial effectiveness of the bioprepared ZnO-NPs and their synergism with fosfomycin were evaluated using disk diffusion assay against the concerned pathogens. Transmission electron microscopy (TEM) investigation of the bioprepared ZnO-NPs showed that their average particle size was 18.93 ± 2.65 nm. Escherichia coli expressed the highest sensitivity to the bioinspired ZnO-NPs with a suppressive zone of 22.54 ± 1.26 nm at a concentration of 50 µg/disk, whereas the maximum synergistic effect of the bioinspired ZnO-NPs with fosfomycin was noticed against Klebsiella pneumoniae strain with synergism ratio of 100.29%. In conclusion, the bioinspired ZnO-NPs demonstrated significant antibacterial and synergistic efficacy with fosfomycin against the concerned nosocomial bacterial pathogens, highlighting the potential of using the ZnO NPs-fosfomycin combination for effective control of nosocomial infections in intensive care units (ICUs) and health care settings. Furthermore, the biogenic ZnO-NPs’ potential antibacterial action against food pathogens such as Salmonella typhimurium and E. coli indicates their potential usage in food packaging applications.

The photocatalytic, cytotoxicity, and antibacterial properties of zinc oxide nanoparticles synthesized using Trigonella foenum-graecum L extract

In this study, the manufacture of zinc oxide nanoparticles (ZnO-NPs) was completed via the sol-gel method with Trigonella foenum-graecum L extract for the first time to function as the stabilizing and reducing agent. The obtained product was investigated by various analyzing procedures such as TGA/DTG, FT-IR, UV-Vis, XRD, and EDX/FESEM. The calcination of our product was conducted at temperatures of 400, 500, and 600 °C. In conformity to the XRD pattern, heightening the temperature of calcination caused an enlargement in the size of nanoparticles. The photocatalytic performance of ZnO-NPs was evaluated to degrade methylene blue and Eriochrome black T (EBT) dyes under UV light, which resulted in a degradation percentage of about 96% and 94%, after 90 min, respectively. There has been some evidence suggesting that the green synthesis of ZnO-NPs has increased their use in medicine. The outcomes of examining the cytotoxicity effect of this product against the Huh-7 cell line by the performance of the MTT assay were indicative of an IC₅₀ of around 62.5 µg/mL. Finally, according to the results of the broth microdilution method, which was performed to assess the antibacterial activity of ZnO-NPs towards gram-positive and gram-negative bacteria, the value of MIC was in the range of 31 to 125 µg/mL. The obtained results from biological studies confirm the antibacterial and anticancer properties of ZnO-NPs, which are promising for applying NPs in medical fields.

Ahmed E, Battah B, Abd Ellah NH, Zanetti S, Donadu MG. Nanotechnology as a Promising Approach to Combat Multidrug Resistant Bacteria: A Comprehensive Review and Future Perspectives

The wide spread of antibiotic resistance has been alarming in recent years and poses a serious global hazard to public health as it leads to millions of deaths all over the world. The wide spread of resistance and sharing resistance genes between different types of bacteria led to emergence of multidrug resistant (MDR) microorganisms. This problem is exacerbated when microorganisms create biofilms, which can boost bacterial resistance by up to 1000-fold and increase the emergence of MDR infections. The absence of novel and potent antimicrobial compounds is linked to the rise of multidrug resistance. This has sparked international efforts to develop new and improved antimicrobial agents as well as innovative and efficient techniques for antibiotic administration and targeting. There is an evolution in nanotechnology in recent years in treatment and prevention of the biofilm formation and MDR infection. The development of nanomaterial-based therapeutics, which could overcome current pathways linked to acquired drug resistance, is a hopeful strategy for treating difficult-to-treat bacterial infections. Additionally, nanoparticles' distinct size and physical characteristics enable them to target biofilms and treat resistant pathogens. This review highlights the current advances in nanotechnology to combat MDR and biofilm infection. In addition, it provides insight on development and mechanisms of antibiotic resistance, spread of MDR and XDR infection, and development of nanoparticles and mechanisms of their antibacterial activity. Moreover, this review considers the difference between free antibiotics and nanoantibiotics, and the synergistic effect of nanoantibiotics to combat planktonic bacteria, intracellular bacteria and biofilm. Finally, we will discuss the strength and limitations of the application of nanotechnology against bacterial infection and future perspectives.

Phyto-Mediated Controllable Synthesis of ZnO Clusters with Bactericidal Activity

The rapid development of antibiotic resistance has been considered a major threat to public health. Nanomaterials have risen to be an effective weapon to tackle this problem through multiple antibacterial mechanisms. The improved and tailored physiochemical properties of fine-tuned secondary nanoarchitectures contribute to the superior bactericidal actions of metal oxide structures. However, it is still challenging to construct secondary structures through mild green manufacturing methods. Here, we report the preferred antibacterial ZnO nanocrystal clusters formed by a green structure-tuning synthesis process, in which the primary ZnO nanoparticles with sizes <10 nm were assembled into different forms of clusters depending on the zinc salt concentration and temperature. ZnO clusters with a stable loose-assembly structure and a rougher surface exhibited better bactericidal ability with minimal inhibitory concentrations of 0.5 and 0.1 mg/mL against Escherichia coli and Staphylococcus aureus, respectively. The underlying mechanism is related to enhancing contact with bacteria, releasing small ZnO nanoparticles, and generating additional reactive oxygen species, which could aggravate the damage to bacterial cell membrane and eventually lead to bacterial death. Furthermore, attachment of phenolic compounds from olive leaf extract would promote membrane penetration by ZnO nanoparticles, resulting in the improvement of antibacterial activities, which profit from the green route mediated by Olea europaea leaf extract that could structure-tune ZnO nanocrystal clusters in one simple step that retains the active ingredients on the nanoparticles. This work proposes a feasible and clean strategy to improve the structure-bioactivity relationship of ZnO by controlling its growth into a preferable structure, and the developed ZnO clusters have a good prospect in antibacterial applications because of their excellent performance and green fabrication method.

Bacterial Pathogens in the Food Industry: Antibiotic Resistance and Virulence Factors of Salmonella enterica Strains Isolated from Food Chain Links

Salmonella is one of the most important foodborne pathogens. Fifty-three strains of Salmonella deposited in the Culture Collection of Industrial Microorganisms-Microbiological Resources Center (IAFB) were identified using molecular and proteomic analyses. Moreover, the genetic similarity of the tested strains was determined using the PFGE method. Main virulence genes were identified, and phenotypical antibiotic susceptibility profiles and prevalence of resistance genes were analyzed. Subsequently, the occurrence of the main mechanisms of β-lactam resistance was determined. Virulence genes, invA, fimA, and stn were identified in all tested strains. Phenotypic tests, including 28 antibiotics, showed that 50.9% of the strains were MDR. The tet genes associated with tetracyclines resistance were the most frequently identified genes. Concerning the genes associated with ESBL-producing Salmonella, no resistance to the TEM and CTX-M type was identified, and only two strains (KKP 1597 and KKP 1610) showed resistance to SHV. No strains exhibited AmpC-type resistance but for six Salmonella strains, the efflux-related resistance of PSE-1 was presented. The high number of resistant strains in combination with multiple ARGs in Salmonella indicates the possible overuse of antibiotics. Our results showed that it is necessary to monitor antimicrobial resistance profiles in all food chain links constantly and to implement a policy of proper antibiotic stewardship to contain or at least significantly limit the further acquisition of antibiotic resistance among Salmonella strains.

Current Research on Zinc Oxide Nanoparticles: Synthesis, Characterization, and Biomedical Applications

Zinc oxide nanoparticles (ZnO-NPs) have piqued the curiosity of researchers all over the world due to their extensive biological activity. They are less toxic and biodegradable with the capacity to greatly boost pharmacophore bioactivity. ZnO-NPs are the most extensively used metal oxide nanoparticles in electronic and optoelectronics because of their distinctive optical and chemical properties which can be readily modified by altering the morphology and the wide bandgap. The biosynthesis of nanoparticles using extracts of therapeutic plants, fungi, bacteria, algae, etc., improves their stability and biocompatibility in many biological settings, and its biofabrication alters its physiochemical behavior, contributing to biological potency. As such, ZnO-NPs can be used as an effective nanocarrier for conventional drugs due to their cost-effectiveness and benefits of being biodegradable and biocompatible. This article covers a comprehensive review of different synthesis approaches of ZnO-NPs including physical, chemical, biochemical, and green synthesis techniques, and also emphasizes their biopotency through antibacterial, antifungal, anticancer, anti-inflammatory, antidiabetic, antioxidant, antiviral, wound healing, and cardioprotective activity. Green synthesis from plants, bacteria, and fungus is given special attention, with a particular emphasis on extraction techniques, precursors used for the synthesis and reaction conditions, characterization techniques, and surface morphology of the particles.

Synergistic Effect of Static Magnetic Field and Modified Atmosphere Packaging in Controlling Blown Pack Spoilage in Meatballs

This study aimed to compare the microbial diversity in meatballs with or without blown pack spoilage (BPS) to determine the cause of BPS and to assess the synergistic effect of static magnetic field (SMF) and modified atmosphere packaging (MAP) to reduce the phenomenon of BPS. Results showed that the BPS group with a 2.26-fold larger volume and packaging containing 71.85% CO₂ had Klebsiella spp. (46.05%) and Escherichia spp. (39.96%) as the dominant bacteria, which was different from the spoilage group. The results of isolation and identification of strains from the BPS group and their inoculation test confirmed that Klebsiella pneumoniae was the major strain-inducing BPS in meatballs due to its pack-swelling ability. SMF (5 mT) treatment combined with MAP (40%CO₂ + 60%N₂), which did not influence the sensory quality of meatballs, had a significant synergistic effect on preventing the increase in pack volume. Compared with the control group, this synergistic treatment effectively delayed bacterial growth, drop in pH, and the increase of TBARS. The findings of this study will provide further guidance for meatball manufacturers to adopt effective strategies to reduce the BPS of meatballs.