Antimicrobial Ability Research Articles

Kaolinite-mediated synthesis of ultra-small silver nanoparticles with high antimicrobial activity.

Ultra-small Ag nanoparticles (<5 nm) loaded on a kaolinite surface were successfully prepared in large batches by a dry-process, displaying excellent broad-spectrum antimicrobial ability and size-dependent activity. This Ag-loaded kaolinite (Ag@AT/K) inhibited the growth of pathogenic bacteria and accelerated wound healing in in vivo experiments on MRSA-infected wounds. This work provides a new strategy for the preparation of mineral-based nanoscale antibacterial materials.

One-step fabrication of an injectable antibacterial collagen hydrogel with in situ synthesized silver nanoparticles for accelerated diabetic wound healing

Developing antibacterial collagen-based wound dressings that target multidrug-resistant bacteria holds promise for healing diabetic wounds prone to infection, yet traditional approaches pose persistent challenges of cytotoxicity and uneconomical steps. To address these issues, we develop a biocompatible, eco-friendly, one-step cross-linking and reduction strategy, fabricating injectable antibacterial collagen hydrogels containing in situ-generated silver nanoparticles for diabetic wound care. By exposing the collagen-silver ion (Ag+) mixture to visible light, collagen-silver nanoparticle (Col I/AgNPs) hydrogels were one step created, eliminating the need for additional cross-linkers and toxic reducing agents. The synergistic interaction between collagen and silver ions was the first time investigated, revealing a pivotal redox reaction with a dual role that simultaneously initiated collagen cross-linking and reduced Ag+ to AgNPs. The resulting biocompatible Col I/AgNPs hydrogel was found to have multifunctional properties, exhibiting excellent injectability, enhanced biological activity, and outstanding broad-spectrum antimicrobial ability. Furthermore, animal experiments utilizing a diabetic full-thickness wound model demonstrated their excellent in vivo healing efficacies, capable of establishing efficient antibacterial barriers and serving as bioactive regenerative scaffolds. Our study proposes an innovative one-step approach to create injectable antibacterial collagen-silver nanoparticle hydrogels, highlighting their potential as advanced dressings for diabetic wound treatment and other biomedical applications.

Orientational Nanoconjugation with Gold Endows Marked Antimicrobial Potential and Drugability of Ultrashort Dipeptides.

Antibiotic resistance is a global threat. Antimicrobial peptides (AMPs) are highly desirable to treat multidrug-resistant pathogen infection. However, few AMPs are clinically available, due to high cost, instability, and poor selectivity. Here, ultrashort AMPs (2-3 residues with an N-terminal cysteine) are designed and assembled as gold nanoparticles. Au-S conjugation and ultrashort size restrict nonspecific reactions and peptide orientation, thus concentrating positively charged residues on the surface. The nanostructured assemblies enormously enhance antimicrobial abilities by 1000-6000-fold and stability. One representative (Au-Cys-Arg-NH2, Au_CR) shows selective antibacterial activity against Staphylococcus aureus with 10 nM minimal inhibitory concentration. Au_CR has comparable or better in vivo antimicrobial potency than vancomycin and methicillin, with low propensity to induce resistance, little side effects, and high stability (17.5 h plasma half-life). Au_CR acts by inducing collapse of membrane potential and rupture of the bacterial membrane. The report provides insights for developing AMP-metal nanohybrids, particularly tethering nonspecific reactions and AMP orientation on the metal surface.

Development of an In Situ Photo-Crosslinking Antimicrobial Collagen Hydrogel for the Treatment of Infected Wounds.

Antimicrobial hydrogels have received considerable attention in the treatment of bacteria-infected wounds. Herein, we develop a neutral, soluble collagen via modification with maleic anhydride, serving as a hydrogel precursor. Maleic anhydride-modified collagen (ColME) could form a gel after exposure to UV light and be loaded with the antimicrobial agents, nisin and levofloxacin, to acquire antimicrobial ability. The ColME hydrogel containing nisin and levofloxacin had good cytocompatibility and effectively killed pathogenic bacterial strains, such as Escherichia coli and Staphylococcus aureus. The antimicrobial ColME hydrogels effectively supported the healing of a full-thickness skin wound infected with S. aureus in a mouse model. Our results demonstrate the potential of antimicrobial hydrogels as effective wound dressings via in situ photogelation for the healing of infected wounds.

Enterococcus species: insights into antimicrobial resistance and whole-genome features of isolates recovered from livestock and raw meat in Ghana.

Enterococcus spp. have gradually evolved from commensals to causing life-threatening hospital-acquired infections globally due to their inherent antimicrobial resistance ability and virulence potential. Enterococcus spp. recovered from livestock and raw meat samples were characterized using antimicrobial susceptibility testing and whole-genome sequencing. Isolates were confirmed using the MALDI-ToF mass spectrometer, and antimicrobial susceptibility was determined using the Kirby-Bauer disk diffusion method. Whole genome sequencing was performed on isolates resistant to two or more antibiotics. Bioinformatics analysis was performed to determine sequence types, resistance and virulence gene content and evolutionary relationships between isolates from meat and livestock samples, and other enterococci genomes curated by PATRIC. eBURST analysis was used to assign genomes to clonal complexes. Enterococcus spp. were predominantly E. faecalis (96/236; 41%) and E. faecium (89/236; 38%). Overall, isolates showed resistance to erythromycin (78/236; 33%), tetracycline (71/236; 30%), ciprofloxacin (20/236; 8%), chloramphenicol (12/236; 5%), linezolid (7/236; 3%), ampicillin (4/236; 2%) and vancomycin (1/236, 0.4%). Resistance to two or more antimicrobial agents was detected among 17% (n = 40) Enterococcus spp. Resistance genes for streptogramins [lsa(A), lsa(E), msr(C)], aminoglycosides [aac(6')-Ii, aph(3')-III, ant(6)-Ia, aac(6')-aph(2″), str], amphenicol [cat], macrolides [erm(B), erm(T), msr(C)], tetracyclines [tet(M), tet(L), tet(S)] and lincosamides [lsa(A), lsa(E), lnu(B)] were detected among the isolates. Genes for biofilm formation, adhesins, sex pheromones, cytolysins, hyaluronidase, oxidative stress resistance, quorum-sensing and anti-phagocytic activity were also identified. Potential plasmids with replicon sequences (rep1, rep2, repUS43, repUS47, rep9a, rep9b) and other mobile genetic elements (Tn917, cn_5536_ISEnfa1, Tn6009, ISEnfa1, ISEfa10) were detected. Clinically relevant E. faecium ST32 and ST416 clones were identified in meat samples. The occurrence of antimicrobial-resistant Enterococcus spp. in livestock and raw meat samples, carrying multiple resistance and virulence genes, including known clones associated with hospital-acquired infections, underscores the critical need for employing robust tools like whole genome sequencing. Such tools provide detailed data essential for ongoing surveillance efforts aimed at addressing the challenge of antimicrobial resistance with a focus on one health.

Isolation and Characterization of Antimicrobial Peptides Isolated from Brevibacillus halotolerans 7WMA2 for the Activity Against Multidrug-Resistant Pathogens.

Multidrug resistance to pathogens has posed a severe threat to public health. The threat could be addressed by antimicrobial peptides (AMPs) with broad-spectrum suppression. In this study, Brevibacillus halotolerans 7WMA2, isolated from marine sediment, produced AMPs against Gram-positive and Gram-negative bacteria. The AMPs were precipitated by ammonium sulfate 30% (w/v) from culture broth and dialyzed by a 1kDa membrane. Tryptone Soy Agar (TSA) was used for the cultivation and resulted in the largest bacteria-inhibiting zones under aerobic conditions at 25°C, 48h. An SDS-PAGE gel overlay test revealed that strain 7WMA2 could produce AMPs of 5-10kDa and showed no degradation when held at 121°C for 30min at a wide pH 2-12 range. The AMPs did not cause toxicity to HeLa cells with concentrations up to 500µg/mL while increasing the arbitrary unit up to eight times. The study showed that the AMPs produced were unique, with broad-spectrum antimicrobial ability.

On the Silver Nanomaterials in Healthcare Applications

Silver nanomaterials (AgNMs) have gained attention for their potential applications in the field of healthcare due to their unique physicochemical properties. These properties include a high surface area to volume ratio, catalytic activity, and strong antimicrobial abilities. Research has shown that AgNMs have the potential to be used as an effective antimicrobial agent against a broad range of pathogens, including antibiotic-resistant strains. Moreover, AgNMs have shown great potential in wound healing due to their ability to enhance cell proliferation and skin regeneration. Another potential application of silver nanomaterials in healthcare is drug delivery. Due to small size and high surface area, they have been used as effective carriers of therapeutics in targeted drug delivery. However, it is important to note that more research is needed to fully understand the potential risks and benefits of utilizing silver nanomaterials in healthcare. Researchers should investigate the potential toxicity of silver nanomaterials and their impact on the environment. Moreover, standardized protocols for the synthesis and characterization of AgNMs should be developed to ensure their reproducibility, stability, and effectiveness. In conclusion, AgNMs have shown immense potential in the field of healthcare due to their unique properties. However, more research and careful evaluation are essential to fully comprehend the potential advantages and risks of utilizing AgNMs in healthcare. The plausible toxicity of AgNPs in healthcare applications is also discussed.

A polylactide based multifunctional hydrophobic film for tracking evaluation and maintaining beef freshness by an electrospinning technique.

A nanofiber film was prepared by a facile electrospinning technique using polylactide (PLA), butterfly pea flower extract (BPA) and cinnamaldehyde (CIN). The as-prepared film shows the prominent antioxidative, antibacterial, colorimetric and hydrophobic properties so that the beef freshness can be monitored and maintained up to 6days at 4°C simultaneously. Besides, the nanofiber structure endows the film with a fast color responsiveness under acidic-alkaline atmospheres with different concentrations. Moreover, this film exhibits higher tensile strength (9.56 Mpa) than that of the pure PLA electrospinning film (4.40 Mpa). Especially the introduction of the BPA effectively boosts the antimicrobial ability of the CIN. The freshness, sub-freshness and spoilage levels of the beef can be easily testified by observing the color difference change of the film. So the polylactide based multifunctional film as an intelligent packaging has an excellent potential for the sub-freshness detection of meat.

Singlet oxygen generation efficiency and antimicrobial ability in glutathione protected Ag31 nanoclusters

Ligand protected silver nanoclusters (Ag NCs) have recently been reported to have significant applications as antimicrobial agents. In the current study, glutathione (SG) protected silver nanocluster was synthesized leading to Ag31SG19 by cyclic reduction and oxidative condition and was evaluated for its singlet oxygen generation and antibacterial activity. From the results of the study, Ag31SG19 was found to have inhibitory activity against Escherichia coli and Staphylococcus aureus with a diameter of 15.30 ± 0.58 mm and 16.70 ± 0.58 mm respectively. The Minimum Inhibitory Concentration was also calculated to have 0.3125 mg/ml and 0.1562 mg/ml respectively. In addition, the Ag31SG19 was found to have high efficiency for the generation of singlet oxygen. Based on the results of the study, the antimicrobial mechanisms of Ag31SG19 could be predicted to be mainly because of the generation of singlet oxygen species in addition to the activity due to the release of Ag+ ions from the nanoclusters. These multimechanistic antimicrobial effects make the synthesized Ag31SG19 to be a promising candidate for a broad range of antimicrobial applications.

Carboxymethyl cellulose/poly (vinyl alcohol) based active film incorporated with tamarind seed coat waste extract for food packaging application

Incorporating a bioactive food waste extract into biodegradable polymers is a promising green approach to producing active films with antioxidant and antibacterial activity for food packaging. Active packaging films from carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) incorporated with tamarind seed coat waste extract (TS) were prepared by solvent casting method using citric acid as a crosslinking agent. The effect of TS content on the film properties was determined by measuring the optical, morphology, mechanical, water vapor transmission rate (WVTR), antioxidant, and antimicrobial attributes. The CMC/PVA-TS films were also tested on fresh pork. The addition of TS did not significantly affect the film structure and WVTR but it improved the mechanical and UV barrier properties. The films possessed antioxidant and antimicrobial ability against bacteria (S. aureus and E. coli). Thus, CMC/PVA packaging was successfully prepared, and the incorporation of TS enhanced the antioxidant and antimicrobial properties of the film, which extended the shelf-life of fresh pork.

Lysosomal Cu(I)/Cu(II) Dependence of Antimicrobial Ability of Oyster Hemocytes and Regulation of Phagolysosomal System.

Copper (Cu) is hyperaccumulated in oyster hemocytes and is an essential trace metal indispensable for diverse innate immune functions. However, the roles of Cu in oyster immune defense are still unclear. In this study, Cu exposure enhanced the phagocytosis of zymosan by increasing the number and length of filopodia, as well as mitochondrial ROS (mitoROS) production mainly in granulocytes, followed by semigranulocytes and agranulocytes. The intracellular calcium level increased to promote the phagosome-lysosome fusion after Cu exposure. The enhancement of phagosomal acidification and mitochondrion-phagosome juxtaposition were also found in granulocytes after Cu exposure. These results indicated that Cu could regulate the phagolysosomal system to enhance the antimicrobial ability of oyster hemocytes with the assistance of mitoROS. Furthermore, Cu(I) and Cu(II) were predominately located in lysosomes, and degranulation may provide a mechanism for exposing Cu to bacteria to prevent their survival and proliferation. Specifically, we showed that the newly formed Cu(I) arising from lysosomal Cu(II) moved to lysosomes and mitochondria in activated hemocytes to induce strong immune responses. The ability of the transformation of Cu(I) from Cu(II) followed granulocytes > semigranlocytes > agranulocytes, indicating that granulocytes played important roles in immune functions of oysters. Our results provided new insights into the understanding of antimicrobial effects of Cu in oyster hemocytes.

Excellent Dark/Light Dual-Mode Photoresponsive Activities Based on g-C3N4/CMCh/PVA Nanocomposite Hydrogel Using Electron Beam Radiation Method.

Photocatalytic technology for inactivating bacteria in water has received much attention. In this study, we reported a dark-light dual-mode sterilized g-C3N4/chitosan/poly (vinyl alcohol) hydrogel (g-CP) prepared through freeze-thaw cycling and an in situ electron-beam radiation method. The structures and morphologies of g-CP were confirmed using Fourier infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), solid ultraviolet diffuse reflectance spectroscopy (UV-vis DRS), and Brunauer-Emmett-Teller (BET). Photocatalytic degradation experiments demonstrated that 1 wt% g-CP degraded rhodamine B (RhB) up to 65.92% in 60 min. At the same time, g-CP had good antimicrobial abilities for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) within 4 h. The shapes of g-CP were adjustable (such as bar, cylinder, and cube) and had good mechanical properties and biocompatibility. The tensile and compressive modulus of 2 wt% g-CP were 0.093 MPa and 1.61 MPa, respectively. The Cell Counting Kit-8 (CCK-8) test and Hoechst33342/PI double staining were used to prove that g-CP had good biocompatibility. It is expected to be applied to environmental sewage treatment and wound dressing in the future.

Blend of natural and natural identical essential oil compounds as a strategy to improve the gut health of weaning pigs

Weaning is one of the most critical phases in pig’s life, often leading to postweaning diarrhoea (PWD). Zinc oxide (ZnO), at pharmacological doses, has been largely used to prevent PWD; however, due to antimicrobial co-resistant and environmental pollution issues, the EU banned its use in June 2022. Natural or natural identical components of essential oils and their mixture with organic acids are possible alternatives studied for their antimicrobial, anti-inflammatory and antioxidant abilities. This study aimed to evaluate the effect of two blends of natural or natural identical components of essential oils and organic acids compared to ZnO on health, performance, and gut health of weaned pigs. At weaning (d0), 96 piglets (7 058 ± 895 g) were assigned to one of four treatments balanced for BW and litter: CO (control treatment), ZnO (2 400 mg/kg ZnO from d0 to d14); Blend1 (cinnamaldehyde, ajowan and clove essential oils, 1 500 mg/kg feed); Blend2 (cinnamaldehyde, eugenol and short- and medium-chain fatty acids, 2 000 mg/kg feed). Pigs were weighed weekly until d35. Faeces were collected at d13 and d35 for microbiota (v3–v4 regions of the 16 s rRNA gene) and Escherichia coli (E. coli) count analysis. At d14 and d35, eight pigs/treatment were slaughtered; pH was recorded on intestinal contents and jejunal samples were collected for morphological and gene expression analysis. From d7–d14, the Blend2 had a lower average daily gain (ADG) than CO and ZnO (P < 0.05). ZnO and Blend1 never differed in ADG and feed intake. At d14, ZnO had a lower caecum pH than all other treatments. The CO treatment had a higher abundance of haemolytic E. coli than Blend1 (P = 0.01). At d13, the ZnO treatment had a lower alpha diversity (P < 0.01) and a different microbial beta diversity (P < 0.001) compared to the other treatments. At d13, the ZnO treatment was characterised by a higher abundance of Prevotellaceae_NK3B31_group (Linear Discriminant Analysis (LDA) score = 4.5, P = 0.011), Parabacteroides (LDA score = 4.5, P adj. = 0.005), the CO was characterised by Oscillospiraceae UCG-005 (LDA score = 4.3, P adj. = 0.005), Oscillospiraceae NK4A214_group (LDA score = 4.2, P adj. = 0.02), the Blend2 was characterised by Megasphaera (LDA score = 4.1, P adj. = 0.045), and Ruminococcus (LDA score = 3.9, P adj. = 0.015) and the Blend1 was characterised by Christensenellaceae_R-7_group (LDA score = 4.6, P adj. < 0.001) and Treponema (LDA score = 4.5, P adj. < 0.001). In conclusion, Blend1 allowed to maintain the gut health of postweaning piglets through modulation of the gut microbiome, the reduction of haemolytic E. coli while Blend2 did not help piglets.

Preparation and properties of chitosan/dialdehyde sodium alginate/dopamine magnetic drug-delivery hydrogels

The proportion of individuals with bladder cancer has drastically increased, thereby rendering bladder cancer a focus of social concern and great challenge for human health management. Hydrogels with three-dimensional network structures have attracted considerable attention in the field of drug delivery for tumor therapy. Therefore, exploring hydrogel drug-delivery systems with excellent biocompatibility and targeting ability is a current research hotspot. Herein, a chitosan/dialdehyde sodium alginate/magnetic dopamine hydrogel was investigated for this purpose. The hydrogel was prepared from chitosan using sodium dialdehyde alginate and dopamine via grafting, crosslinking, and compounding. Furthermore, characterization of the product structure, targeted adhesion, and evaluation of drug delivery properties were performed. The prepared wall-adherent hydrogel materials exhibited excellent targeted drug-delivery and controlled-release properties. In addition, the effect of dopamine dosage on the performance of drug-loaded hydrogels was examined. In conclusion, the drug-delivery materials exhibited strong organ-wall adhesion, hydrogel properties, targeting ability, antibacterial and antimicrobial abilities (98%), and biocompatibility (99%). Based on these excellent properties, the constructed targeted hydrogels demonstrate considerable potential for drug delivery and bladder cancer treatment.

Antibacterial Activity of Surfactin and Synergistic Effect with Conventional Antibiotics Against Methicillin-Resistant Staphylococcus aureus Isolated from Patients with Diabetic Foot Ulcers.

The prevalence of diabetic foot ulcers (DFUs) is increasing, leading to a huge financial burden and human suffering. Furthermore, antibiotic resistance is an urgent problem in the realm of clinical practice. Antimicrobial peptides are an effective and feasible strategy for combating infections caused by drug-resistant bacteria. Therefore, we investigated the in vitro antimicrobial ability of the lipopeptide surfactin, either alone or in combination with conventional antibiotics, against the standard and clinical strains of Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), isolated from patients with DFUs. The minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of surfactin on the selected strains were evaluated by a microbroth dilution technique. The growth curves of the selected strains with and without surfactin were measured, and transmission electron microscopy was used to observe the structure of surfactin-treated bacterial cells. The biofilm inhibitory abilities of surfactin were assessed by crystal violet staining. The antimicrobial interactions between surfactin and conventional antibiotics were established using a checkerboard assay, as well as determining the mutant prevention concentration. The inhibitory effect of surfactin on penicillinase was tested by iodometry. The MIC and MBC values of surfactin ranged from 512 to 1024 µg/mL and 1024 to 2048 µg/mL, respectively. Moreover, surfactin significantly prevented the S. aureus biofilm formation and displayed limited toxicity on human red blood cells. The synergies between surfactin and ampicillin, oxacillin, and tetracycline against S. aureus were revealed. In vitro resistance was not readily produced by surfactin. The action of surfactin may be by disrupting bacterial cell membranes and inhibiting penicillinase. Surfactin appears to be a potential option for the treatment of DFUs infected with MRSA, as it is capable of improving antimicrobial activities and can be used alone or in combination with conventional antibiotics to prevent or postpone the emergence of resistance.

Strontium-polydopamine hybrid coating to improve antibacterial ability and osseointegration of titanium implants

Poor osseointegration and implant-associated infection of titanium implants have prompted their urgent development. Strontium (Sr) is widely recognized to promote osteoblast differentiation and inhibit osteoclast growth. To this end, this study aimed to develop a Sr-containing polydopamine (PDA)-coated implant with practical antibacterial ability and excellent osseointegration ability to meet clinical applications. This hybrid coating used PDA as an adhesion layer and a carrier for Sr ions. The effects of Sr contents on shear bond strength, in vitro stability, antibacterial ability, and in vitro osteogenic activity of the implant were evaluated. The Sr-doped PDA surface was soaked in simulated body fluid (SBF) at pH 7.4 or 5.0 for a long time (up to 90 days) to evaluate the in vitro stability. The antimicrobial ability of the hybrid coating against E. coli and S. aureus was examined, while its cellular function was assessed using RAW 264.7 and MG63 cells. The current phase and chemical composition results indicated the presence of Sr ions on the surface of PDA. When Sr was added to PDA, the initial shear strength values were comparable to those of the PDA coating. Soaking time reduced the strength values of Sr-containing coatings, especially for 90 days. However, Sr coating significantly reduced the growth of the two bacteria in a dose-dependent manner. Likewise, Sr coating had a significant dose-dependent inhibitory effect on the development of RAW 264.7 cells but improved MG63 osteogenesis. In conclusion, 40 % Sr-containing PDA hybrid coating on titanium implants may be a potential implant in terms of in vitro stability, antibacterial ability, and osteogenic activity.

Modification of microfiltration membranes by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/n-hydroxy sulfosuccinimide coupling mediated antimicrobial peptides grafting for biofouling mitigation

Microfiltration membrane separation is widely applied for water and wastewater but biofouling is a challenging task in real applications. In this work, we fabricated a novel antibiofouling polyvinylidene fluoride (PVDF) membrane by grafting non-drug-resistant antimicrobial peptides (AMPs) on the membranes via 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride/N-hydroxy sulfosuccinimide (EDC/Sulfo-NHS) chemistry. Effects of AMPs concentration on the membrane basic properties, antibacterial and antibiofouling behaviors of the modified membranes were systematically investigated. Membrane surface characterization demonstrated that the AMPs were successfully grafted onto the base PVDF membranes. The AMPs modified membrane showed enhanced hydrophilicity, consistent permeability and prominent antimicrobial ability (i.e., >90% of antibacterial efficiency against both Escherichia coli and Staphylococcus aureus). Batch filtration tests exhibited that the modified membranes with the concentration of AMPs less than or equal to 0.7 mg/mL had lower flux decline rate compared to the pristine membrane (M0). According to the images from confocal laser scanning microscopy analysis, less total cells as well as more dead cells were observed on the AMPs modified membrane compared to M0. Furthermore, the grafted AMPs on the membranes also displayed favorable stability suffered from a cycle involving biofouling and chemical cleaning. This grafting protocol for AMPs highlights a robust way to fabricate antibiofouling membranes for water and wastewater treatment.

Penerapan Teknologi Nanokomposit Pada Kemasan Pangan

Nanotechnology is the manipulation and use of materials and structures on the nanometer scale, roughly between 1 and 100 nm. Nanotechnology has invaded the agri-food industry, with many applications. Nanocomposite is one of the development technologies of Nanotechnology. Nanocomposite packaging is a polymer in which certain types of nano materials have been inserted, such as nano composite clay, nano silica particles (SiO2), carbon nanotubes, graphene, starch nanocrystals, cellulose-based nanofiber or nanowhiskers, chitin chitosan nanoparticles and other inorganics. This paper reviews the main applications of nanocomposites in the field of food packaging. The writing method used in writing this article review is a comparative writing method by collecting various sources obtained from several research journals from 2014 - 2021. From the results of this study, it was found that nanocomposites have very broad potential for their use as food packaging. Such as increasing antimicrobial ability, extending shelf life, maintaining color and sensory quality, as well as other benefits. However, it is necessary to carry out further identification regarding the nature of the interactions between nanoparticles and their effects on the food packaging application process.&#x0D;

Low-cost ZIF-67-modified fabrics with effective photothermal disinfection for antimicrobial personal protective equipment production

Aerosol-based transmission contributes to infection by various pathogens. Consequently, it is urgent to design antimicrobial personal protective equipment (PPE) and address the potential biological contamination of discarded PPE. We report a novel ZIF-67-modified PP fabric for photothermal disinfection; our work provides a fast, one-step, and low-cost preparation approach for incorporating zeolitic imidazolate framework (ZIF) nanoparticles (NPs) onto polypropylene (PP) fabric. First, we prepared ZIF-67-water NPs and ZIF-67-methanol NPs using relevant solvents and characterized them by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and field-emission scanning electron microscopy. We then used only ultrasonication to prepare ZIF-67-modified fabrics by incorporating ZIF-67 NPs onto PP fabric with a 0.5－1.5 mg/cm2 loading rate (18.5－40.5 wt%). The ZIF-67-modified fabrics were subjected to the same characterization, and then they were evaluated for photothermal performance, hydrophobicity and antimicrobial ability. The fabric of ZIF-67-water@PP-1.5 was selected to repurpose an antimicrobial mask. We demonstrated that the ZIF-67-modified fabrics have excellent photothermal performance with near-infrared (NIR) radiation and exhibit increased hydrophobicity, which is determined by the loading rate of ZIF-67 NPs. The surface temperature reached and maintained peak levels (70 °C and 90 °C) with NIR radiation, whilst the highest contact angle was over 140°. The photothermal behaviour could kill over 99.9% of gram-negative and gram-positive drug-resistant bacteria, whilst the haemolytic behaviour was less than 5%. The repurposed mask retained controllable photothermal properties. The application of these fabrics not only addresses the demand for affordable antimicrobial PPE but also contributes to reducing potential biochemical threats in discarded PPE.

Physicochemical Properties of Porang Nanocoating with the Addition of Essential Oils

Porang nanocoating is a food coating that has the potential to be developed and is gaining popularity among the public to extend the shelf life of fruits and vegetables. Porang Nanocoating is a nano-sized edible coating made from porang tuber glucomannan. The addition of essential oils can improve the property of the nanocoating of people as a natural antimicrobial coating. Thyme, cinnamaldehyde and eugenol essential oils are known to have excellent antimicrobial properties. Antimicrobial ability is strongly influenced by the concentration of added essential oil. The purpose of this study was to determine the effect of the type and concentration of essential oils on the physicochemical properties of porang nanocoating. This study used a factorial completely randomized design (CRD) with two factors, namely the type of essential oil treatment including essential oils of thyme, eugenol, cinnamaldehyde. While other treatments are essential oil concentrations, namely 1%, 2%, and 3%. The results of this study indicate that the type of essential oil and its concentration affect the physicochemical properties of the porang nanocoating. The physicochemical properties of porang nanocoating based on the type of essential oil treatment gave the following average values: viscosity 16.67 m.Pa.s. – 17.50 m.Pa.s; degree of acidity (pH) range 6.29 – 6.33; color 13.50 – 13.95; transparency 89.40 – 89.56; has stable emulsion properties or there is no separation of the emulsion and in the microscopic test the oil droplets or bubbles are few While other treatments are essential oil concentrations, namely 1%, 2%, and 3%. The results of this study indicate that the type of essential oil and its concentration affect the physicochemical properties of the porang nanocoating. The physicochemical properties of porang nanocoating based on the type of essential oil treatment gave the following average values: viscosity 16.67 m.Pa.s. – 17.50 m.Pa.s; degree of acidity (pH) range 6.29 – 6.33; color 13.50 – 13.95; transparency 89.40 – 89.56; has stable emulsion properties or there is no separation of the emulsion and in the microscopic test the oil droplets or bubbles are few While other treatments are essential oil concentrations, namely 1%, 2%, and 3%. The results of this study indicate that the type of essential oil and its concentration affect the physicochemical properties of the porang nanocoating. The physicochemical properties of porang nanocoating based on the type of essential oil treatment gave the following average values: viscosity 16.67 m.Pa.s. – 17.50 m.Pa.s; degree of acidity (pH) range 6.29 – 6.33; color 13.50 – 13.95; transparency 89.40 – 89.56; has stable emulsion properties or there is no separation of the emulsion and in the microscopic test the oil droplets or bubbles are few The physicochemical properties of porang nanocoating based on the type of essential oil treatment gave the following average values: viscosity 16.67 m.Pa.s. – 17.50 m.Pa.s; degree of acidity (pH) range 6.29 – 6.33; color 13.50 – 13.95; transparency 89.40 – 89.56; has stable emulsion properties or there is no separation of the emulsion and in the microscopic test the oil droplets or bubbles are few The physicochemical properties of porang nanocoating based on the type of essential oil treatment gave the following average values: viscosity 16.67 m.Pa.s. – 17.50 m.Pa.s; degree of acidity (pH) range 6.29 – 6.33; color 13.50 – 13.95; transparency 89.40 – 89.56; has stable emulsion properties or there is no separation of the emulsion and in the microscopic test the oil droplets or bubbles are few. Treatment of essential oil concentrations gives physicochemical properties to Porang Nanocoating which has an average Viscosity value of 16.11 m.Pa.s. – 18.61 m.Pa.s; The degree of acidity (pH) ranges from 6.25 to 6.39; Color 12.80 – 14.91; Transparency 89.39 – 89.52; has stable properties or does not occur emulsion separation in the stability test and in the microscopic test has few oil droplets or bubbles.