Strong Antibacterial Effect Research Articles

Unraveling the Potential of Organic Oregano and Tarragon Essential Oils: Profiling Composition, FT-IR and Bioactivities

Oregano and tarragon are widely cultivated culinary herbs used for food seasoning, having familiar characteristic aromas appreciated by the wide public. The aim of this research was to characterize essential oils (EOs) from locally sourced organic oregano and tarragon (Cluj, Romania) and study their bioactivity potential. Results showed that oregano EO had a sesquiterpene dominant profile responsible for strong bands between 2800 and 3000 cm−1 on the Fourier transform infrared spectroscopy (FT-IR) spectrum and a composition consistent with reports from similar climatic regions. The tarragon EO profile was defined by phenylpropanoids responsible for the strong sharp peaks between 1000 and 1600 cm−1 on the FT-IR spectrum. In oregano EO, 22 compounds were identified with β-caryophyllene as a major constituent. In tarragon EO, 20 compounds were identified with eugenol as a major constituent. Oregano EO had a stronger antibacterial effect against both Gram-negative and Gram-positive bacterial strains, while tarragon EO had a slightly stronger cytotoxic effect on three types of cancer cell lines tested (skin melanoma, prostate carcinoma, and colorectal adenocarcinoma). It was concluded that, given the fact that a sufficient supply of high-quality plant material can be available for EO extraction, culinary herbs can become reliable candidates for many industries without the risk of discontinued supply. Therefore, research aiming to widen their potential applications is welcome and worth pursuing.

Synthesis and in Silico Studies of Some New 1,2,3-Triazolyltetrazole Bearing Indazole Derivatives as Potent Antimicrobial Agents.

1,2,3-Triazole and tetrazole derivatives bearing pyrrolidines are found to exhibit notable biological activity and have become useful scaffolds in medicinal chemistry for application in lead discovery and optimization. Novel indazole bearing 1,2,3-triazolyltetrazoles were designed as potential antimicrobial candidates. The structure of duel heterocyclics was validated by a spectroscopic technique of infrared (IR), nuclear magnetic resonance (1 H and 13 C NMR), and mass spectral data. Compounds 4b, 4c, 4d, and 4h were found to have a stronger antibacterial effect against Gram-positive (S. aureus, B. subtilis, M. Luteus) and Gram-negative (E. coli, P. aeruginosa) microorganisms with MICs ranging from 5±0.03-18±0.02 μM, respectively. Moreover, scaffolds 4a, 4h showed potent antifungal activity against A. flavus, M. gypsuem strains with MIC values of 10±0.02, 11±0.01 μM, which are similar activity that of the standard Itraconazole (MIC=8±0.02, 10±0.01 μM). The binding mode for compound 4 inside the catalytic pocket of S. aureus complexed with nicotinamide adenine dinucleotide phosphate and trimethoprim and produced a network of hydrophobic and hydrophilic interactions (3FRE). From in silico results, 4b demonstrated highly stable hydrogen binding amino acids Leu62(X) [N18…O, 2.47 Å], Arg44(X) [N17…N, 3.11 Å], Thr96(X) [N10…OG1, 3.05 Å], Gly94(X) [F7…N, 2.82 Å], and Gly43(X) [F7…N, 2.90 Å], which are plays a crucial role in ensuring efficient binding of the ligand in a crystal structure of antibacterial receptor. Furthermore, the physicochemical and ADME filtration molecular properties, estimation of toxicity, and bioactivity scores of these novel scaffolds were evaluated by using SwissADME and ADMETlab2.0 online protocols. Thus, the significant antimicrobial activity of indazole linked to duel heterocyclic compounds can be used for development of new antimicrobial agents with further modifications.

Intelligent antibacterial surface with controllable sterilization and bacteria-releasing ability

Bacterial biofilm contamination has caused significant damage to the medical and food industries, and there is an urgent need to develop new antimicrobial coatings to address this problem. In this study, temperature-sensitive coatings with bacteria-killing and bacteria-releasing functions were prepared based on silicone rubber (SR) surfaces by ultraviolet (UV) polymerization and UV photocatalysis. Firstly, N-isopropylacrylamide (NIPAAm) was formed into poly(N-isopropylacrylamide) (PNIPAAm) by UV polymerization and grafted onto the SR surface. Then, Ag+ was rapidly reduced to silver nanoparticles (AgNPs) by tannic acid (TA) under UV catalysis to form TA@Ag complexes, depositing onto the SR surface. The modified SR surface has an extremely strong and persistent bactericidal effect, greatly inhibiting the formation of bacterial biofilm. Moreover, the smart surface can effectively release bacteria and resist bacterial adhesion through temperature changes. Moreover, the modified SR surface did not exhibit cytotoxicity against mouse epithelioid fibroblasts (L929). Taken together, the smart SR surface has antibacterial ability and good biocompatibility, which is a promising medical material.

The antimicrobial effect of Limosilactobacillus reuterias probiotic on oral bacteria: A scoping review.

Dysbiosis among oral microbial community in the oral cavity can lead to several oral diseases. Probiotic therapy is known to correct these imbalances. Limosilactobacillus reuteri is one of the most studied strains of probiotics and can control oral microbiota through reuterin, a wide-spectrum antimicrobial agent. The objective of this review was to evaluate the effect of the antimicrobial activity of Limosilactobacillus reuteri on the oral bacteria of humans. This review used PubMed, Scopus, EMBASE, ScienceDirect, and Google Scholar databases as bibliographic resources. Studies with matching keywords were analyzed and screened with PRISMA-ScR recommendations. Sixteen articles were selected for this review, which included a total of 832 patients. Based on this review, Limosilactobacillus reuteri has a strong antibacterial effect against Streptococcus mutans in healthy individuals but is not effective against Lactobacillus. Additionally, it has a significant antibacterial effect against Porphiromonas gingivalis in patients with periodontitis, although its effectiveness is not stable in patients with peri-implant infections. Furthermore, Limosilactobacillus reuterihas varying results against other bacteria, indicating the need for further extensive research to ensure its efficacy.

Zwitterion modified cochlear implants resist postoperative infection and inflammation

The cochlear implant (CI), an advanced electronic device replacing the entire cochlear function, is the ultimate treatment for over 466 million people with disabling hearing loss. Infection after cochlear implantation is a common and worrisome complication despite the routine administration of the antibiotic. The bacterial biofilms formed on the surface of CI are the main cause of antibiotic failure. To solve this problem, we developed a copper-containing zwitterionic coating consisting of anti-adherent poly sulfobetaine methacrylate (PSB) and steadfast polydopamine (PDA). CuSO4/H2O2. was added to accelerate this co-deposition reaction and enhance the anti-bacterial property. The preparation method was simple, rapid, and suitable for clinical use. In our in vitro and in vivo studies, the PSB/PDA(Cu) coating showed high biocompatibility, and conferred CI implants excellent anti-inflammatory, strong anti-bacterial effects, and great anti-biofilm properties to representative Gram-positive and Gram-negative bacteria. These findings implied that the PSB/PDA(Cu) coating was a unique anti-bacterial strategy for enhancing CI performance.

Antibacterial potential of silver nanoparticles (SP-AgNPs) synthesized from Syzygium polyanthum (Wight) Walp. against selected foodborne pathogens

Foodborne diseases continue to pose a significant global health concern, causing a considerable number of deaths worldwide. In response to concerns surrounding bacterial resistance and the limitations of traditional antibiotics, there is a growing interest in exploring natural antibacterial agents as potential alternatives for addressing foodborne pathogens. Nowadays efforts are being made on exploring the potential of natural antibacterial agents against foodborne pathogens. In this study, the antibacterial efficacy of silver nanoparticles synthesized using S. polyanthum leaves extract (SP-AgNPs) against selected Gram-negative and Gram-positive foodborne pathogens was investigated by using multiple assays, including the well diffusion assay (WDA), minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and time-kill assay. The well diffusion assay demonstrated the inhibitory potential of SP-AgNPs against all tested foodborne pathogens, with inhibition zones ranging from 10.16 + 1.25 to 13.16 + 1.52 mm. Furthermore, the MIC values ranged from 0.008 to 0.125 mg/mL, indicating the potent antibacterial activity of SP-AgNPs across a broad spectrum of foodborne pathogens. The MBC values, ranging from 0.008 to 0.250 mg/mL, further confirming the bactericidal ability of SP-AgNPs against these pathogens. In the time-kill experiment, most foodborne pathogens were entirely killed after 4 h of incubation at 4 × MIC concentration. However, only E. coli, K. pneumoniae, and S. Typhimurium showed a reduction in population to 3 Log10 CFU/mL, indicating a strong bactericidal effect of SP-AgNPs on most tested pathogens. In conclusion, this study provides compelling evidence that SP-AgNPs exhibit potent antibacterial activity against selected foodborne pathogens. The findings suggest that SP-AgNPs synthesized using S. polyanthum leaves extract hold great promise as a novel antibacterial agent for effectively controlling foodborne pathogens. These findings contribute to continuing efforts in developing alternative strategies to prevent foodborne diseases and enhance food safety.

Ag nanocomposite hydrogels with immune and regenerative microenvironment regulation promote scarless healing of infected wounds

BackgroundBacterial infection, complex wound microenvironment and persistent inflammation cause delayed wound healing and scar formation, thereby disrupting the normal function and appearance of skin tissue, which is one of the most problematic clinical issues. Although Ag NPs have a strong antibacterial effect, they tend to oxidize and form aggregates in aqueous solution, which reduces their antibacterial efficacy and increases their toxicity to tissues and organs. Current research on scar treatment is limited and mainly relies on growth factors and drugs to reduce inflammation and scar tissue formation. Therefore, there is a need to develop methods that effectively combine drug delivery, antimicrobial and anti-inflammatory agents to modulate the wound microenvironment, promote wound healing, and prevent skin scarring.ResultsHerein, we developed an innovative Ag nanocomposite hydrogel (Ag NCH) by incorporating Ag nanoparticles (Ag NPs) into a matrix formed by linking catechol-modified hyaluronic acid (HA-CA) with 4-arm PEG-SH. The Ag NPs serve dual functions: they act as reservoirs for releasing Ag/Ag+ at the wound site to combat bacterial infections, and they also function as cross-linkers to ensure the sustained release of basic fibroblast growth factor (bFGF). The potent antibacterial effect of the Ag NPs embedded in the hydrogel against S.aureus was validated through comprehensive in vitro and in vivo analyses. The microstructural analysis of the hydrogels and the in vitro release studies confirmed that the Ag NCH possesses smaller pore sizes and facilitates a slower, more sustained release of bFGF. When applied to acute and infected wound sites, the Ag NCH demonstrated remarkable capabilities in reshaping the immune and regenerative microenvironment. It induced a shift from M1 to M2 macrophage polarization, down-regulated the expression of pro-inflammatory factors such as IL-6 and TNF-α, and up-regulated the expression of anti-inflammatory IL-10. Furthermore, the Ag NCH played a crucial role in regulating collagen deposition and alignment, promoting the formation of mature blood vessels, and significantly enhancing tissue reconstruction and scarless wound healing processes.ConclusionsWe think the designed Ag NCH can provide a promising therapeutic strategy for clinical applications in scarless wound healing and antibacterial therapy.Graphical

Novel antibacterial titanium implant healing abutment with dimethylaminohexadecyl methacrylate to combat implant-related infections

ObjectiveImplant-related infections from the adhesion and proliferation of dental plaque are a major challenge for dental implants. The objectives of this study were to: (1) develop novel antibacterial titanium (Ti) healing abutment; (2) investigate the inhibition of implant infection-related pathogenic bacteria and saliva-derived biofilm, and evaluate the biocompatibility of the new material for the first time. MethodsDimethylaminohexadecyl methacrylate (DMAHDM) and hydroxyapatite (HAP) were polymerized via polydopamine (PDA) on Ti. Staphylococcus aureus (S. aureus), Streptococcus sanguinis (S. sanguinis) and human saliva-derived biofilms were tested. After 4 weeks of DMAHDM release, the antibacterial efficacy of the DMAHDM remaining on Ti surface and the DMADHM in medium was tested. Biocompatibility was determined using human gingival fibroblasts (HGFs) and periodontal ligament stem cells (PDLSCs). ResultsThe DMAHDM-loaded coating filled into the nano-voids in Ti surfaces. The modified Ti showed potent antibacterial activity, reducing the CFU of S. aureus, S. sanguinis and saliva-derived biofilms by 8, 7 and 4 log, respectively (P < 0.05). After 4 weeks of release, the modified Ti was still able to reduce S. aureus and S. sanguinis biofilm CFU by 1–3 log (P < 0.05). This provided strong antibacterial function for more than 4 weeks, which were the high-risk period for implant infections. The new material showed excellent biocompatibility when compared to control (P > 0.05). ConclusionNovel DMAHDM-loaded Ti healing abutment had strong antibacterial effects, reducing biofilm CFUs by orders of magnitude, and lasting for over four weeks to cover the high-risk period for implant infections. The novel antibacterial Ti is promising to combat implant-related infections in dental, craniofacial and orthopedic applications.

Formulation and Evaluation of Topical Poly Herbal Gel Consisting of Natural Antimicrobials for the Activity against Acne Vulgaris

The purpose of this research paper is to find out which effective antibacterial substances are in different herbs and their use in acne vulgaris and hyperpigmentation. Herbal gel with four herbs mainly including Azadiracta indica, Hibiscus rosa sinesis, Piper Betle and Aloe barbadensis was formulated with a base gel. Two formulations were prepared and evaluated for pH, dispersibility, detergency, and zone of inhibition. Preliminary phytochemical evaluations of the extracts were performed according to the standard procedures. Later antimicrobial activity of the individual extracts and polyherbal gel was determined by the cup plate method. Phytochemical tests showed the presence of alkaloids, terpenoids, flavonoids, saponins, etc. A strong antibacterial effect was found for a polyherbal gel compared with individual extracts against acne vulgaris. Synergistic interaction between secondary plant metabolites present in each extract might be responsible for the better antimicrobial activity of the polyherbal gel.

Preventive Use of Bactericidal Preparations for Cow Dermatitis in Masalli District (Azerbaijan)

For prophylactic purposes against cow dermatitis, the bactericidal effect of drugs HI-7 and Blanidas-300 was studied in vitro. It has been established that a 1.0% solution of the drug HI-7 has a strong bactericidal effect, inhibits the growth of colonies, causing denaturation of proteins of bacterial cells. For prophylactic purposes, the drug is an effective remedy for cow dermatitis. The effectiveness of the drug is explained by the presence of an active substance in its composition — alkyldimethylbenzylammonium chloride.

Effects of Artemisia dracunculus L. and Origanum majorana L. Extracts Added in Different Concentrations on Some Possible Foodborne Pathogenic Bacteria in Hamburger Patties

In this study, the antibacterial effects of distinct concentrations of Origanum majorana L. and Artemisia dracunculus L. extracts added to the formulation of hamburger patties on four different foodborne pathogenic bacteria named Gram positive (Staphylococcus aureus, Listeria monocytegenes) and Gram negative (Salmonella Typhimurium, Escherichia coli), which are the most ones isolated from hamburger patties, were researched. Besides, the use of natural preservatives in conjunction with the additional extracts was also explored to see if the microbiological reliability of hamburger patties could be guaranteed. According to the findings of the research, Origanum majorana L. and Artemisia dracunculus L. extracts were found to have strong antibacterial effects on Gr (+) and Gr (-) pathogenic bacteria inoculated into hamburger patties, and it was discovered that they inhibited at various rates. The antibacterial impact found by the study turned out to be greater on Gr (+) bacteria as compared to Gr (-) bacteria. It was also verified that 2% Artemisia dracunculus L. extract provided the highest antibacterial effect on Listeria monocytegenes with a decrease of 3.38 log cfu/g. Furthermore, it became apparent that the antibacterial impact grew in direct proportion to the concentration applied to the extracts employed, and that the antibacterial effect generated by the Artemisia dracunculus L. extract was stronger and more potent than the Origanum majorana L. extract.

Evaluation of the antibacterial activity and protein profiling of Nile tilapia (Oreochromis niloticus) epidermal mucus under different feeds and culture systems (biofloc technology and earthen pond).

The mucus layers of fish serve as the main interface between the organism and the environment. They play an important biological and ecological role. The current study focuses on Nile tilapia epidermal mucus reared under different commercial feeds (coded A and B) and environments (biofloc technology and earthen pond systems). Crude protein levels in feed A and B were 30% and 28%, respectively. Water parameters in all culturing systems were suitable for tilapia throughout the study period. The antimicrobial potency of tilapia (n = 5 from each) epidermal mucus was tested invitro against human and fish pathogenic strains viz. Staphylococcus epidermidis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Francisella noatunensis, and Aeromonas hydrophila. To determine the antimicrobial activity, zones of inhibition (ZOI) were measured in millimetres and compared with two antibiotics (chloramphenicol and ciprofloxacin). SDS-PAGE analysis was performed on skin mucus samples of tilapia to determine protein quantity and size (molecular weight). Results of tilapia skin mucus (crude and aqueous) revealed a strong antibacterial effect against all the selected pathogenic strains. However, variation has been observed in the mucus potency and ZOI values between the biofloc and pond tilapia mucus. The crude mucus of tilapia fed on feed A and cultured in the pond exhibited strong antibacterial effects and high ZOI values compared to the mucus of biofloc tilapia, aqueous mucus extracts and positive control chloramphenicol (antibiotic). The SDS-PAGE results showed that the high molecular weight proteins were found in the collected epidermal mucus of BFT-B (240 kDa) and EP-B (230 kDa). Several peptides in fish skin mucus may play a crucial role in the protection of fish against disease-causing pathogens. Thus, it can be utilized in the human and veterinary sectors as an 'antimicrobial' for treating various bacterial infections.

Multifunctional chemoreactive nanosonosensitizers exert antitumoral, antibacterial and wound healing effects on malignant peripheral nerve sheath tumors

Currently, surgery is the only available and effective clinical strategy for treating malignant peripheral nerve sheath tumors. However, even with complete surgical resection, poor physical health or cachexia can cause wound delay or infection. To solve this critical issue, DSF-CuO2@DMSN nanoparticles were rationally designed. These nanoparticles have been engineered to exert high performance and synergistic sonodynamic/chemodynamic/chemotherapeutic tumor treatment under the stimulation of ultrasound by producing reactive oxygen species and dithiocarbamate − copper complexes in situ in response to the tumor-specific acidic and hypoxic microenvironment. When mixed with thermosensitive hydrogels, the therapeutic effects of nanosonosensitizers can be precisely limited to the working areas. Significant inhibition of proliferation, increases in apoptosis and death in tumor cells and xenograft all demonstrated the antitumoral capability of DSF-CuO2@DMSN under ultrasound stimulation. The upregulated expression of caspase-3 related proteins and the results of RNA sequencing indicated the induction of cell apoptosis, autophagy, or cell death after treatment. Moreover, DSF-CuO2@DMSN induced strong antibacterial effects and wound healing abilities under the activation of ultrasound, with quick wound closure and the absence of bacterial infection in in vitro and in vivo experiments. Altogether, the multifunctional DSF-CuO2@DMSN nanoagents can provide a distinct postoperative therapeutic strategy for both tumor inhibition and wound recovery.

A review on deterioration of textile cultural heritage objects and sustainable solutions to mitigate the degradation

Heritage textiles are important evidence of human history. Folk costumes, quilts, tapestries, rugs, hangings, etc. constitute a rich collection of products that are particularly valuable but also extremely fragile. This paper presents the main causes of the deterioration of heritage textiles, followed by a summary of the main bio-treatments that are effective in their case. Essential oils and plant extracts have a strong antibacterial, antifungal and insecticidal effect and are therefore recommended to be used as sustainable alternatives to conventional treatments. At present, bio-treatments used to prevent and reduce the deterioration of heritage textiles are carried out in two ways. One of them targets bioaerosols in museum spaces and the second one targets microbial agents on the surface or in the structure of textiles. The application of bio-treatments on heritage textiles should be done taking into account the specific features given by their fibrous composition, the structure of the materials, their age, the environmental conditions in which they are, etc. At present, these treatments are not yet commonly used for heritage textiles or the spaces in which they are stored or exhibited, even though there are studies that have proven the effectiveness and safety of their use.

A review on deterioration of textile cultural heritage objects and sustainable solutions to mitigate the degradation

Heritage textiles are important evidence of human history. Folk costumes, quilts, tapestries, rugs, hangings, etc. constitute a rich collection of products that are particularly valuable but also extremely fragile. This paper presents the main causes of the deterioration of heritage textiles, followed by a summary of the main bio-treatments that are effective in their case. Essential oils and plant extracts have a strong antibacterial, antifungal and insecticidal effect and are therefore recommended to be used as sustainable alternatives to conventional treatments. At present, bio-treatments used to prevent and reduce the deterioration of heritage textiles are carried out in two ways. One of them targets bioaerosols in museum spaces and the second one targets microbial agents on the surface or in the structure of textiles. The application of bio-treatments on heritage textiles should be done taking into account the specific features given by their fibrous composition, the structure of the materials, their age, the environmental conditions in which they are, etc. At present, these treatments are not yet commonly used for heritage textiles or the spaces in which they are stored or exhibited, even though there are studies that have proven the effectiveness and safety of their use.

Antibacterial properties of metal nanoparticles–incorporated activated carbon composites produced from waste biomass precursor

Activated carbon-based composite materials, together with the well known antibacterial activity of metal nanoparticles, urged the performance of this study to prepare new antibacterial materials with antimicrobial activity, as an important step in fighting pathogenic organisms. Activated carbon derived from a waste source - almond shells - were combined with metal (Ag, Cu, Mg) nanoparticles, in order to obtain metal composite with desirable characteristics. The composites were obtained using one-step high-temperature hydro-pyrolysis and further impregnation of the metal from water solution. Investigation of the structure, chemical composition and morphology of obtained composites was carried out by scanning electron microscopy, XRD, XPS, elemental and BET analysis, before testing their antimicrobial activity. Strongest antibacterial effect against E. coli was observed when 10 % Cu Activated Carbon Composite (ACCCu) was used attaining 100 % reduction of microbial count even at the starting point. ACCAg, ACCMg and activated carbon only, demonstrated such effect after 24 h. Best results after treatment of S. aureus were achieved with ACCAg and ACCCu after 24 h.The results indicate that the antibacterial activity depends on the contact time, bacterial species, nature of the metal and metal concentration. The novel metal nanoparticles-incorporated activated carbon composites demonstrated very good antibacterial activity. The investigation provides novel materials with antibacterial properties for further development and potential application in hygiene devices.

Uncovering the anti-biofilm activity of Ilicicolin B against Staphylococcus aureus

The formation of bacterial biofilms reduces the entry of antibiotics into bacteria and helps bacteria tolerate otherwise lethal concentrations of antimicrobials, leading to antibiotic resistance. Therefore, clearing bacterial biofilm is an effective strategy to tackle drug resistance. Currently, there are no approved antibiotics for inhibiting bacterial biofilm formation. We found that Ilicicolin B had excellent antibacterial activity against MRSA without obvious hemolytic activity. More importantly, Ilicicolin B effectively inhibited the biofilm formation in a concentration-dependent manner by crystal violet colorimetric assay and fluorescence microscopy analysis. Exposure of Staphylococcus aureus to Ilicicolin B for 24 h reduced the protein and polysaccharide components in EPS, suggesting that Ilicicolin B disintegrated the biofilms by dissociating the EPS in a matrix. In addition, Ilicicolin B demonstrated strong antibacterial effects in a murine abscess model of S. aureus. Our findings suggest that Ilicicolin B has the potential to treat S. aureus infection by inhibiting biofilm formation.

Technological Interest and Antimicrobial Activity of Lactic Acid Bacteria Isolated from Date Paste of the Ghers Variety (Bechar, South-West of Algeria)

Background: Dates are high nutritional value fruits. They are the basis of many traditional products and compose several oases by-products. Among these products, date paste represents a form of conservation widely practiced in Algeria to valorize common date’s surplus production for commercial purposes. Methods: First, microbiological analysis was carried out to isolate lactic acid bacteria (LAB) from date’s paste and microbial contaminants from both date fruit by-products according to standard microbiological methods before investigating the technological characteristics attributed to the isolated LAB. Second, the antimicrobial effect was evaluated through three different techniques. Result: Nine microbial contaminants were isolated from date paste and date extract, while eight LAB strains were isolated from date paste, which belong to the Streptococci and Leuconostoc strains. The SLM1 strain revealed a good acidifying power going up to 5.13 g/L of lactic acid within 6 hours of incubation compared to the other LAB strains. A moderate to strong antibacterial effect ranging up to a 20 mm zone of inhibition was revealed against bacterial contaminants. In decreasing order, the antifungal effect was significant against Penicillium sp, Aspergillus niger and A. flavus. The isolated lactic strains of streptococci could be good candidates for food preservation by extending the shelf life of foods and improving their nutraceutical and hygienic quality.

Nanosilver Embedded in a Magnetosome Nanoflower to Enhance Antibacterial Activity for Wound Dressing Applications.

The natural biofilm on magnetosomes obtained from the biomineralization of magnetotactic bacteria, which replaced a complex chemical modification process on the surface of Fe3O4, can be used as the organic component and copper(II) ions as the inorganic component to form organic-inorganic nanoflowers in phosphate systems. Characterization by scanning electron microscopy, Fourier transform infrared spectroscopy, and vibrating-sample magnetometry proved that magnetic nanoflowers loaded with silver ions (Ag/MN-Cu×NFs) were successfully fabricated. In vitro antibacterial experiments demonstrated that Ag/MN-Cu×NFs displayed strong antibacterial effects against Escherichia coli and Staphylococcus aureus, with minimum inhibitory concentrations of 10 and 80 μg/mL, respectively. Ag/MN-Cu×NFs, which possessed good biocompatibility as confirmed by cytotoxicity and hemolysis tests, were able to promote wound healing in the face of bacterial infection in vivo without causing toxicity to major organs. Therefore, magnetosomes as a natural carrier have great application potential in the synthesis of multifunctional magnetosomes by direct hybridization with a target substance.

Morphological, thermo-mechanical, and barrier properties of coextruded multilayer polylactide composite films reinforced with graphene nanoplatelets and encapsulated thyme essential oil

The food industry has been looking for biodegradable active packaging film, which has a lower environmental footprint and can extend shelf-life. This work aimed to develop a polylactide-based antibacterial nanopackaging with a tri-layer structure. This coextruded tri-layer film was composed of an internal extruded layer of polylactide (PLA), a central layer of PLA loaded with encapsulated thyme essential oil, and an outer layer of PLA with graphene nanoplatelets. The tri-layer packaging films' morphological, rheological, thermal, barrier, and antibacterial properties were evaluated and compared to those of their single-layer counterparts. Dispersion of nanoparticles in PLA matrix or in composites is described by rheological, thermal, and XRD analysis. The multilayer films displayed some roughness on the surface, and heterogeneity can be seen through phase imaging compared to single-layer films. Antibacterial assays of the film confirmed a strong bactericidal effect against gram-positive and gram-negative bacteria, maintaining this activity for 21 days.