Effect of Polyethylene Film Thickness on the Antimicrobial Activity of Embedded Zinc Oxide Nanoparticles

Anti-Microbial, Thermal, Mechanical, and Gas Barrier Properties of Linear Low-Density Polyethylene Extrusion Blow-Molded Bottles

Microbial contamination can occur on the surfaces of blow-molded bottles, necessitating the development and application of effective anti-microbial treatments to mitigate the hazards associated with microbial growth. In this study, new methods of incorporating anti-microbial particles into linear low-density polyethylene (LLDPE) extrusion blow-molded bottles were developed. The anti-microbial particles were thermally embossed on the external surface of the bottle through two particle deposition approaches (spray and powder) over the mold cavity. The produced bottles were studied for their thermal, mechanical, gas barrier, and anti-microbial properties. Both deposition approaches indicated a significant enhancement in anti-microbial activity, as well as barrier properties, while maintaining thermal and mechanical performance. Considering both the effect of anti-microbial agents and variations in tensile bar weight and thickness, the statistical analysis of the mechanical properties showed that applying the anti-microbial agents had no significant influence on the tensile properties of the blow-molded bottles. The external fixation of the particles over the surface of the bottles would result in optimum anti-microbial activity, making it a cost-effective solution compared to conventional compounding processing.

Biological Activities of Zinc Oxide Nanoparticles Green Synthesized Using the Aqueous Extract of Dracocephalum kotschyi Boiss

BACKGROUND

Dracocephalum kotschyi Boiss. is known as a native medicinal plant of Iran.

OBJECTIVE

In this study, aqueous extract of D. kotschyi was used to synthesize ZnO-NPs. To produce ZnO-NPs, aerial parts of D. kotschyi were powdered and then macerated for obtaining aqueous extract, after that, aqueous extract was used to reduse zinc nitrate to ZnO-NPs.

METHODS

To confirm nanoparticles synthesis, SEM, TEM, UV-Vis, FTIR, and XRD were used. The synthesized ZnO-NPs were studied for antimicrobial activities by microdilution method for calculating MIC and MBC. Analysis of ZnO-NPs confirmed successful synthesis by extract of D. kotschyi.

RESULTS

The sizes of ZnO-NPs were estimated 50-200 nm in diameter. Antibacterial and antifungal experiments showed potent activities against Staphylococos aureus, Pseudomonas aeruginosa and Candida albicans. The results of the studies showed that the nanoparticles synthesized with the aqueous extract of D. kotschyi have a much greater antimicrobial effect than the aqueous extract of D. kotschyi and zinc nanoparticles, each alone (MIC values 3.7 to 7.5 mg/ml).

CONCLUSION

The noteworthy point is that the inhibitory rate of synthesized zinc oxide nanoparticles is higher compared to broad-spectrum antibiotics, such as chloramphenicol (MIC values 15 mg/ml). Determining the therapeutic and toxic dose of this product for humans requires further investigation and clinical trials.

Bioactive ZnO Nanoparticles: Biosynthesis, Characterization and Potential Antimicrobial Applications

In recent years, biosynthesized zinc oxide nanoparticles (ZnONPs) have gained tremendous attention because of their safe and non-toxic nature and distinctive biomedical applications. A diverse range of microbes (bacteria, fungi and yeast) and various parts (leaf, root, fruit, flower, peel, stem, etc.) of plants have been exploited for the facile, rapid, cost-effective and non-toxic synthesis of ZnONPs. Plant extracts, microbial biomass or culture supernatant contain various biomolecules including enzymes, amino acids, proteins, vitamins, alkaloids, flavonoids, etc., which serve as reducing, capping and stabilizing agents during the biosynthesis of ZnONPs. The biosynthesized ZnONPs are generally characterized using UV-VIS spectroscopy, TEM, SEM, EDX, XRD, FTIR, etc. Antibiotic resistance is a serious problem for global public health. Due to mutation, shifting environmental circumstances and excessive drug use, the number of multidrug-resistant pathogenic microbes is continuously rising. To solve this issue, novel, safe and effective antimicrobial agents are needed urgently. Biosynthesized ZnONPs could be novel and effective antimicrobial agents because of their safe and non-toxic nature and powerful antimicrobial characteristics. It is proven that biosynthesized ZnONPs have strong antimicrobial activity against various pathogenic microorganisms including multidrug-resistant bacteria. The possible antimicrobial mechanisms of ZnONPs are the generation of reactive oxygen species, physical interactions, disruption of the cell walls and cell membranes, damage to DNA, enzyme inactivation, protein denaturation, ribosomal destabilization and mitochondrial dysfunction. In this review, the biosynthesis of ZnONPs using microbes and plants and their characterization have been reviewed comprehensively. Also, the antimicrobial applications and mechanisms of biosynthesized ZnONPs against various pathogenic microorganisms have been highlighted.

Investigating migration potential of a new rechargeable antimicrobial coating for food processing equipment

Antimicrobial coatings are designed to inhibit the growth of pathogens and have been used to reduce foodborne illness bacteria on food processing equipment. Novel N-halamine based antimicrobial coatings are highly advantageous due to their unique properties and low cost, and are being investigated for applications in food safety, health care, water and air disinfection, etc. In this study, we evaluated the chemical safety of a novel N-halamine antimicrobial polymer coating (Halofilm) for use on food processing equipment. Migration tests were performed on stainless steel tiles prepared with four different treatment groups: negative control, positive control, Halofilm coating without chlorination, and Halofilm coating with chlorination. An LC-MS/MS method was developed and validated for four formulation components: polyethylenimine (PEI), Trizma^® base, hydantoin acrylamide (HA) and dopamine methacrylamide (DMA), followed by stability and recovery tests. Migration tests were conducted at 40 °C with three food simulants (10, 50 and 95% ethanol/water) to mimic various food properties, and aliquots of migration extracts were analyzed at 2, 8, 72, 240 and 720 h. In general, measured concentration levels were consistent among simulant types for the four tested chemicals. Chlorinated tiles had non-detects for three analytes (PEI, HA and DMA), and less than 0.05 mg/kg of HA migration over 30 days. A chlorination step could possibly change the measured mass (m/z) hence leading to non-detects in targeted LC-MS/MS. In non-chlorinated tiles, all four compounds were detected during the migration test. This suggests that addition of the chlorination step may have a stabilizing effect on the polymer. Additionally, full scan high resolution mass spectrometry (HRMS) analysis was employed to screen for migration of other extractable and leachable (E&L) chemicals, which led to the identification of eight common E&L chemicals. To our knowledge, this is the first report evaluating chemical migration from an N-halamine antimicrobial polymer coating product.

Antimicrobial Nanomaterials as Advanced Coatings for Self-Sanitizing of Textile Clothing and Personal Protective Equipment

Controlling bioaerosols has become increasingly critical in affecting human health. Natural product treatment in the nano form is a potential method since it has lower toxicity than inorganic nanomaterials like silver nanoparticles. This research is important for the creation of a bioaerosol control system that is effective. Nanoparticles (NPs) are gradually being employed to use bacteria as a nonantibiotic substitute for treating bacterial infections. The present study looks at nanoparticles' antimicrobial properties, their method of action, their impact on drug-opposing bacteria, and the hazards connected with their operation as antimicrobial agents. The aspects that influence nanoparticle conduct in clinical settings, as well as their distinctive features and mode of action as antibacterial assistants, are thoroughly examined. Nanoparticles' action on bacterial cells is presently accepted by way of the introduction of oxidative stress induction, metal-ion release, and nonoxidative methods. Because many concurrent mechanisms of action against germs would necessitate multiple simultaneous gene modifications in the same bacterial cell for antibacterial protection to evolve, bacterial cells developing resistance to NPs is difficult. This review discusses the antimicrobial function of NPs against microbes and presents a comprehensive discussion of the bioaerosols: their origin, hazards, and their prevention. This state of the art method is dependent upon the use of personal protective gear against these bioaerosols. The benefit of the utmost significant categories of metal nanoparticles as antibacterial agents is given important consideration. The novelty of this review depends upon the antimicrobial properties of (a) silver (Ag), (b) zinc oxide (ZnO), and (c) copper oxide (CuO) nanoparticles. The value-added features of these nanoparticles are discussed, as well as their physicochemical characterization and pharmacokinetics, including the toxicological danger they pose to people. Lastly, the effective role of nanomaterials and their future in human wellness is discussed.

Active Packaging Material Based on Immobilized Diatomaceous Earth/Zinc Oxide/High-Density Polyethylene Composite for Sea Food and Products

One of the key factors of supporting the rapidly expanding seafood product industry in terms of quality control is the utilization of active packaging materials. Microorganisms are primarily responsible for the perishability and rapid disintegration of seafood. The incorporation of an inorganic compound, such as silica-based diatomaceous earth (DE), and a metal oxide, such as zinc oxide (ZnO), is proposed to develop active packaging materials with excellent antibacterial activity, minimized fishy odor, and brittleness at subzero temperatures. The mechanical, morphological, and physicochemical properties of these materials were investigated. The results show that the addition of DE/ZnO improved the antibacterial activity of high-density polyethylene (HDPE) samples by up to approximately 95% against both gram-positive and -negative bacteria. Additionally, it enhanced the Izod strength and stability at subzero temperatures of the samples. The odor evaporation test revealed that trimethylamine can be minimized in proportion to increasing DE/ZnO composite concentration. As a result, the development of active packaging materials from DE/ZnO composites is an emerging polymeric packaging technology for seafood products, wherein packaging and seafood quality are linked.

Fabrication of a Polybutylene Succinate (PBS)/Polybutylene Adipate-Co-Terephthalate (PBAT)-Based Hybrid System Reinforced with Lignin and Zinc Nanoparticles for Potential Biomedical Applications

Polybutylene adipate-co-terephthalate (PBAT) was used in an effort to improve the properties of polybutylene succinate (PBS). The resultant blend consisting of PBS/PBAT (70/30) was reinforced with lignin at different loadings (5 to 15 wt.%) and zinc (ZnO) nanoparticles (1.5 wt.%). Hot melt extrusion and injection moulding were used to prepare the hybrid composites. The mechanical, thermal, physical, self-cleaning, and antimicrobial properties of the resultant hybrid composites were investigated. The transmission electron microscopy (TEM) results confirmed that ZnO was successfully prepared with average diameters of 80 nm. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) confirmed that there were interactions between the fillers and the blend. The tensile strength and elongation at the break of the resultant materials decreased with increasing the loadings, while the tensile modulus showed the opposite trend. The melting behaviour of the blend was practically unaffected by incorporating lignin and ZnO nanoparticles. In addition, the incorporation of fillers reduced the thermal stability of the materials. Furthermore, the incorporation of ZnO nanoparticles introduced photocatalytic properties into the polymer blend, rendering it to be a functional self-cleaning material and enhancing its antimicrobial activities.