Antimicrobial Activity Research Articles

Long-term storage of pink pepper essential oil microencapsulated by chickpea protein/pectin complexes: volatile release, antioxidant and antimicrobial activities.

Pink pepper essential oil was microencapsulated with chickpea protein (CP) and chickpea protein/pectin (CP-HMP) by spray drying. The reconstitution and storage properties of the powders were evaluated after drying. The impact of microencapsulation in the volatiles release, antioxidant and antimicrobial activity of oil was evaluated during 135days of storage. CP resulted in more soluble powders (93.52%), CP/HMP resulted in denser powders (0.39g/mL) while wall material did not influence the wettability. Free pink pepper essential oil (FEO) showed a slight loss of the predominant terpenes (α-pinene, β-pinene, β-mircene, δ-3-carene and D-limonene) after encapsulation. In general, all samples showed an increase in the volatiles release during storage. The evaluation of mass loss showed that FEO had a high release of volatiles, followed by CP and CP-HMP. The antioxidant activity of the FEO decreased (10.8μg Trolox/mg of oil) after 135days of storage, whereas the antioxidant activity of CP (14.9) and CP-HMP (14) increased. Both microcapsules presented antimicrobial activity against Bacillus subtilis and Staphylococcus aureus during storage. CP microcapsules had a strong inhibitory effect against the strains tested, and this advantage was even more evident in long-term storage.

Evaluation of Novel HLM Peptide Activity and Toxicity against Planktonic and Biofilm Bacteria: Comparison to Standard Antibiotics.

Antibiotic resistance is one of the main concerns of public health, and the whole world is trying to overcome such a challenge by finding novel therapeutic modalities and approaches. This study has applied the sequence hybridization approach to the original sequence of two cathelicidin natural parent peptides (BMAP-28 and LL-37) to design a novel HLM peptide with broad antimicrobial activity. The physicochemical characteristics of the newly designed peptide were determined. As well, the new peptide's antimicrobial activity (Minimum Inhibitory Concentration (MIC), Minimum Bacterial Eradication Concentration (MBEC), and antibiofilm activity) was tested on two control (Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922) and two resistant (Methicillin-resistant Staphylococcus aureus (MRSA) ATCC BAA41, New Delhi metallo-beta- lactamase-1 Escherichia coli ATCC BAA-2452) bacterial strains. Furthermore, synergistic studies have been applied to HLM-hybridized peptides with five conventional antibiotics by checkerboard assays. Also, the toxicity of HLM-hybridized peptide was studied on Vero cell lines to obtain the IC50 value. Besides the percentage of hemolysis action, the peptide was tested in freshly heparinized blood. The MIC values for the HLM peptide were obtained as 20, 10, 20, and 20 μM, respectively. Also, the results showed no hemolysis action, with low to slightly moderate toxicity action against mammalian cells, with an IC50 value of 10.06. The Biomatik corporate labs, where HLM was manufactured, determined the stability results of the product by Mass Spectrophotometry (MS) and High-performance Liquid Chromatography (HPLC) methods. The HLM-hybridized peptide exhibited a range of synergistic to additive antimicrobial activities upon combination with five commercially available different antibiotics. It has demonstrated the biofilm-killing effects in the same concentration required to eradicate the control strains. The results indicated that HLM-hybridized peptide displayed a broad-spectrum activity toward different bacterial strains in planktonic and biofilm forms. It showed synergistic or additive antimicrobial activity upon combining with commercially available different antibiotics.

Characterization of bioactive compounds, antioxidants and antimicrobial properties of Allagoptera leucocalyx

Allagoptera leucocalyx is a non-studied tropical fruit distributed in the Bolivian Chiquitania region. This study aimed to investigate its bioactive compounds as well as its antioxidant and antimicrobial properties to encourage its consumption and explore potential applications in various industries. The bioactive compounds: polyphenols, flavonoids, and anthocyanins were determined by the Folin-Ciocalteu, AlCl3, and differential pH methods. Antioxidant activity was assessed by the DPPH● and ABTS● assays, while antimicrobial activity by turbidimetry and antibiogram. The highest results obtained revealed significant levels of polyphenols (209 ± 12 mg GAE/100 g), and flavonoids (7.9 ± 0.1 mg QE/100 g). Moreover, the fruit exhibit antioxidant activity (9.3 ± 0.2 μmol Trolox/g by ABTS● and 5.9 ± 0.2 μmol Trolox/g by DPPH●) and antimicrobial activity against Shigella sp. In conclusion, these promising findings suggest that this fruit could be utilized in the development of new products within the cosmetic, food, and pharmaceutical industries.

Discovery of the Aminated Quinoxalines as Potential Active Molecules

Background: In recent years, as the biological activity of the quinoxaline skeleton has been revealed in numerous studies, interest in synthesizing new prototype molecules for the treatment of many chronic diseases, especially cancer, has increased. Methods: The desired alkoxy substituted aminoquinoxalines (AQNX1-9) were synthesized by the reaction of QNX and alkoxy substituted aryl amines such as 2-methoxyaniline, 4-methoxyaniline, 2- ethoxyaniline, 3-ethoxyaniline, 4-ethoxyaniline, 4-butoxyaniline, 2,4-dimethoxyaniline, 3,4- dimethoxyaniline, and 3,5-dimethoxyaniline according to the previously published procedure. QNX was aminated in DMSO at 130°C. We synthesized various alkoxy-substituted aminoquinoxaline compounds (AQNX1-9) and evaluated their anticancer and antimicrobial activities in order to expand the search to related structures. In particular, two aminoquinoxaline (AQNX5 and AQNX6) compounds, coded as NSC D-835971/1 and NSC D-835972/1 by the National Cancer Institute in the USA, were screened for anticancer screening at a dose of 10-5 M on a full panel of 60 human cell lines obtained from nine human cancer cell types (leukemia, melanoma, non-small cell lung, colon, central (nervous system, ovarian, kidney, prostate, and breast cancer). Results: Further in silico studies were also conducted for the compound AQNX5 (NSC D- 835971/1), which was found to be the most active antiproliferative agent, especially against leukemia cell lines. Molecular docking studies showed that AQNX5 interacted with Glu286 and Lys271 through hydrogen bonding and π-stacking interaction in the ATP binding region of Abl kinase, which is indicated as a potential target of leukemia. Besides, AQNX5 occupied the minor groove of the double helix of DNA via π-stacking interaction with DG-6. Conclusion: According to in silico pharmacokinetic determination, AQNX5 was endowed with drug-like properties as a potential anticancer drug candidate for future experiments. In the light of these findings, more research will focus on aminated quinoxalines' ability to precisely target leukemia cancer cell lines.

Formulation and Development of Clove and Coriander Combination Herbal Dental Anticaries Gel and Evaluation of its Antimicrobial Activity

Background:: Dental caries is one of the Periodontal diseases that has been recognized as a major public health problem for decades throughout the world. It occurs in all groups, ethnicities, races, and genders at all socioeconomic levels. Natural remedies are more acceptable in the belief that they are safer with fewer side effects than synthetic ones. Clove and coriander oil are established herbal drugs for periodontal diseases. Objective:: This research work was intended to formulate a dental gel containing clove and Coriander as the major constituents and evaluate it for dental caries treatment. Both of the herbal oils have a vast range of antimicrobial activity against a great number of periodontal pathogens; therefore, they are used for periodontitis treatment. Methods:: The combination gel was prepared using carbopol 934 as a gelling agent, clove oil and coriander oil as therapeutic constituents, polyethylene glycol as a co-solvent, methyl paraben and propyl paraben as a preservative and a required quantity of distilled water as vehicle. Results:: The gel was analyzed for various properties like antimicrobial activity, pH, spreadability, extrudability, drug content etc., and it was shown that the combination gel is a satisfactory dosage form that is used in periodontitis treatment. The combination gel revealed the ZI (zone of inhibition) of about 22.05±0.04 mm. Conclusion:: The present study concluded that the combination gel preparations of clove oil and coriander oil reported satisfactory physicochemical properties along with good drug content compared to the single gel preparation.

Bioengineering of glucan coated silver nanoparticles as dynamic biomedical compound; in vitro and in vivo studies

The use of silver nanoparticles (AgNPs) gaining importance for the treatment of microbial infections and are in great demand due to their efficient broad antibacterial action but there is only one problem that silver nanoparticles can cause tissue damage. Therefore, the present study evaluated antimicrobial potential and intricacy of glucan coated silver nanoparticles in comparison with free silver nanoparticles. In this study, glucan coated silver nanoparticles (Glucan-AgNPs) by using Pleurotus spps. were characterized for their antimicrobial, minimum inhibitory concentration (MIC), biofilm inhibition, mutagenicity potential, hemolytic activities and histological examination through in vitro and in vivo analysis. The liver, kidney, intestine, and skin tissues were examined to gauge the adverse effects of the treatment method's toxicity by silver deposition. The results of this study have shown that mushroom’s glucan extracted from Pleurotus spps. are excellent reducing agent and due to their best capping ability they reduce the toxicity of AgNPs and enhance their antimicrobial activities. The highest zone of inhibition was observed by Glucan-AgNPs from P. ostreatus (24 mm) against S. aureus while least zone of inhibition was resulted from Glucan-AgNPs from P. sapidus (14 mm) against B. subtilis. The results for biofilm inhibition showed excellent biofilm inhibition ability of Glucan-AgNPs. In results, maximum inhibition 95.2% was observed by Glucan-AgNPs from P. ostreatus against S. aureus, while minimum inhibition 79.2% by Glucan-AgNPs of P. sapidus against E. coli. Furthermore, Glucan-AgNPs treated mice showed no deposition and damage in the organs. Glucan-AgNPs has a higher efficacy in treating microbial infection.

Cu nanoparticles, a candidate biocide for the conservation of stone monuments against biodeterioration

Nanomaterials, such as TiO2, ZnO, and Cu, have become popular materials for controlling the growth of microorganisms that cause the deterioration of stone monuments, but it is not clear which material is best. In this study, the dominant strains from two stone monuments, the Klippe Statue and Lingyan Temple, were used to compare the antimicrobial activities of the three materials. The minimum inhibitory concentrations (MICs) of the three materials were obtained using the microdilution and macrodilution methods, a linear regression model of the relationship between the addition of the nanomaterial and the color change of the stone was constructed, and the antimicrobial effect of the screened nanomaterial applied to the stone samples was also evaluated. Among the three materials, only the Cu nanoparticles exhibited a broad antimicrobial activity, and its MIC was 0.5%. There was a linear relationship between the addition of Cu nanoparticles and the color change of the stone, the maximum addition without significant effect on the aesthetic appearance was 67 μg/cm2, and there was no difference between the limestone and sandstone. However, the antimicrobial activity of the Cu nanoparticles was only observed in limestone due to the low concentration of the material that could be retained on the sandstone surface. In addition, the adsorption between the Cu nanoparticles and limestone was weak and easily removed by various factors, indicating that the microorganisms could re-colonize the Cu-treated limestone after the limestone was exposed to environmental influences such as rainfall. In this paper, we propose a candidate biocide, Cu nanoparticles, to inhibit the growth of microorganisms on stone monuments, the Klippe Statue and Lingyan Temple, and our results provide a reference for the application of nanomaterials in stone monuments.

Antimicrobial activity of herbal biomass derived metabolites fabricated wound dressing material against microbial strains causing skin infection

In the present study, anti-microbial activity of wound dressing material coated with Aloe vera and Azadirachta indica metabolites was investigated on pathogenic microbial strains associated with skin infection. Anti-microbial active metabolites extracted from the respective medicinal plant were fabricated on the wound dressing material by simple, in situ green science principles. Confirmation of phytochemicals fabrication on the fibre surface of the material was studied by Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) Additionally, the impact of phyto-constituents fabrication on mechanical properties such as thickness and tensile strength was assessed. The anti-microbial efficacy of the fabricated dressing against pathogenic microorganisms (Candida albicans, Escherichia coli ATCC 25922, and Staphylococcus aureus ATCC 25923) was evaluated using agar diffusion assay. The release profile of phytochemical constituents from the fabricated wound dressing was investigated using ethanol and distilled water as solvents. The results showed that the phytochemical constituents were fabricated effectively on the wound dressing material and exhibiting notable growth inhibition potential against tested pathogenic strains. The release profile study revealed an initial burst release of phytochemical constituents followed by a controlled or sustained pattern. In conclusion, wound dressings infused with plant extracts present a promising approach for wound care applications and show potential for various healing-related purpose.

Cholesteryl ester transfer protein inhibition: a pathway to reducing risk of morbidity and promoting longevity.

To review the evidence and describe the biological plausibility for the benefits of inhibiting cholesteryl ester transfer protein (CETP) on multiple organ systems through modification of lipoprotein metabolism. Results from observational studies, Mendelian randomization analyses, and randomized clinical trials support the potential of CETP inhibition to reduce atherosclerotic cardiovascular disease (ASCVD) risk through a reduction of apolipoprotein B-containing lipoproteins. In contrast, raising high-density lipoprotein (HDL) particles, as previously hypothesized, did not contribute to ASCVD risk reduction. There is also an expanding body of evidence supporting the benefits of CETP inhibition for safeguarding against other conditions associated with aging, particularly new-onset type 2 diabetes mellitus and dementia, as well as age-related macular degeneration, septicemia, and possibly chronic kidney disease. The latter are likely mediated through improved functionality of the HDL particle, including its role on cholesterol efflux and antioxidative, anti-inflammatory, and antimicrobial activities. At present, there is robust clinical evidence to support the benefits of reducing CETP activity for ASCVD risk reduction, and plausibility exists for the promotion of longevity by reducing risks of several other conditions. An ongoing large clinical trial program of the latest potent CETP inhibitor, obicetrapib, is expected to provide further insight into CETP inhibition as a therapeutic target for these various conditions.

Strengthened Antimicrobial and Biocompatible of Jelleine-1 Analogs: A Step Toward Food Preservation

Antimicrobial peptides (AMPs), as important components of the innate immune system, are deemed to have the potential to replace antibiotics and traditional chemical preservatives due to their natural antibacterial properties and less likely to cause bacterial resistance. In this study, the antimicrobial peptide Jelleine-1 derived from bee royal jelly was used as a template, which provided an effective design scheme for short-chain AMPs based on a natural structure. The peptide structure was characterized by circular dichroism and fluorescence spectroscopy, and the antimicrobial activity and biocompatibility were evaluated. Additionally, a preliminary study on the antibacterial mechanism was carried out. The results indicated that the designed peptides predominantly exhibited a regular β-sheet conformation, in which J-R and F-K had strong antibacterial activity and excellent biocompatibility, the average therapeutic index (TI) was 23.83 and 30.67. The antibacterial mechanism suggested that the increased outer membrane permeability caused strong fluctuation of bacterial cell membrane potential and cytoplasmic depolarization through electrostatic adsorption to the bacterial membrane surface, and further induced inner membrane damage, eventually leading to bacterial death. This study provides a promising approach to the design and development of innovative biological preservatives.

Chemical constituents from the rhizomes of Paris xuefengshanensis

Five new steroidal saponins, xuefengshanosides A–E; one new stilbene trimer, xuefengshansin; and 16 known compounds were isolated from the rhizomes of Paris xuefengshanensis (Melanthiaceae). The chemical structures of the compounds were elucidated by MS and NMR data analyses, ECD calculations, and acidic hydrolysis experiments. The cytotoxicity and antimicrobial activities of the selected compounds were evaluated. Ophiopogonin C′, paris saponin I, paris saponin H, and paris saponin VII showed the most inhibitory activity against five human cancer cell lines and one normal cell line. Xuefengshansin showed weak cytotoxic and antibacterial activities. Paris saponin I was the most active compound against the five tested fungal strains. This species contains structurally diverse compounds that exhibit significant anticancer and antimicrobial activities, suggesting its potential for future development and utilization.

Preparation and properties of calcium oxide and calcium peroxide from eggshell waste for enhanced antimicrobial activity

Calcium peroxide (CaO2), which releases hydrogen peroxide (H2O2) upon contact with water, has garnered attention as a potential alternative to liquid H2O2. Researchers have explored various methods to enhance the production of CaO2 with reduced environmental impact. This study focuses on the preparation of two potent antimicrobial agents, calcined calcium oxide (C-CaO) and synthesized calcium peroxide (S-CaO2) from eggshell waste. These agents were then incorporated into ethylene vinyl alcohol (EVOH) composite films for antimicrobial packaging. The synthesized CaO and CaO2 were analyzed using Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA) and Scanning electron microscopy (SEM). The results confirmed the successful synthesis of high-purity CaO and CaO2 from eggshell waste. Compared to CaO (a well-known antimicrobial agent), CaO2 exhibited approximately 1.6 to 2 times higher antimicrobial activity, which is attributed to its release of H2O2. EVOH films containing 3% of CaO2 demonstrated significant microbial growth deactivation, reaching 99.99% and 97.24% for gram-negative and gram-positive bacteria, while EVOH films containing 3% of CaO exhibited relatively low deactivation ability of 79.01% and 48.82, respectively. This study underscores the potential of eggshell waste as a valuable resource for producing high-value materials. Moreover, CaO2 emerges as an effective antimicrobial agent, particularly in antimicrobial packaging applications, showcasing its versatility across various sectors.

Catalytic and biocidal activity of silver and gold nanoparticles obtained by green synthesis using aqueous extracts of glossy privet (Ligustrum lucidum) dry fruits

Metallic nanoparticles (NPs) have gained interest due to their practical applications in various areas. The synthesis of NPs from biomass proposes a simple, economical and environmentally friendly alternative. In this work, gold NPs (AuNPs) and silver NPs (AgNPs) were synthesized from aqueous extracts of dried Ligustrum lucidum fruits. The biomolecules of the extract, in addition to acting as a reducing agent, are absorbed on the surface of the NPs giving excellent colloidal stability, increasing their catalytic capacity reflected in their recyclability. The TON and TOF values obtained for the reduction reaction of 4-nitrophenol in the presence of NaBH4, are 1.4 105 and 500 s−1 respectively. Minimum inhibitory concentrations (MICs) were established for AgNPs using pathogens from certified collections (E. coli MIC = 25 µg/mL; S. aureus MIC = 100 µg/mL). Fractional inhibitory concentration indices (FICIs) in the presence of gentamicin showed synergistic effects (FICI = 0.5). The results demonstrate that the aqueous extract of L. lucidum allows the synthesis of AuNPs and AgNPs, which have attractive catalytic and antimicrobial activities, in a simple and environmentally friendly way.

Green fused nanoparticles from seaweed as a sustainable resource: Study on antimicrobial activities against human pathogens and photocatalytic degradation of methylene blue (MB) dye

The simple, fast, efficient route and eco-friendly synthesis of silver nanoparticles (Ag-NPs) using the marine-algae Padina pavonica (PP) extracts. The heat bio-reduction process involves using PP extract mediated to synthesize silver (Ag) nanoparticles (NPs). The PP extract provides an eco-friendly, low-cost, and safer alternative to traditional chemical and physical methods. The GC–MS results detect GLYCERYL TRIDODECANOATE, DODECANOIC ACID, and 1,2,3-PROPANETR dominantly examined majorly play a role in synthesizing the Ag-NPs. The synthesized PP-mediated NPs were denoted as PPAg-NPs and characterized the structural and morphological properties by UV–vis spectroscopy, XRD, SEM, HRTEM, EDS, DLS, and FT-IR. The 16S rDNA technique confirmed 6 (n = 6) human pathogens (HPs) strains were used for the antimicrobial study. Green synthesized PPAg-NPs showed a maximum and minimum inhibition growth zone of 16 mm in Escherichia coli, and 10 mm in Bacillus subtilis. The study result suggested the PPAg-NPs act with high efficiency and display greater sensitivity for antibacterial material depending on the concentrations. The synthesized green PPAg-NPs investigated the photocatalytic degradation of methylene blue (MB) dye. The highest 90 % efficiency was achieved under UV-light treatment within 105 min. The study’s outcome indicates that PPAg-NPs exhibit a strong antimicrobial efficacy toward HPs and MB decolorization that contributes to water cleansing, healthcare, and biomedical industries.

Impact of mutations in carbohydrate binding sites of tandem-repeat type galectin from Takifugu obscurus on its antimicrobial activity

Impact of mutations in carbohydrate binding sites of tandem-repeat type galectin from Takifugu obscurus on its antimicrobial activity

Repurposing of monocyclic β-lactams as anti-inflammatory agents – The case of new ferrocene-azetidin-2-one hybrids

There is growing interest in developing monotherapy drugs that treat inflammation caused by microbial infections, focusing on dual antimicrobial and anti-inflammatory agents with minimal side effects and high safety margins. This study synthesized and characterized a library of novel cis-4-ferrocenylazetidin-2-ones, evaluating their antimicrobial and anti-inflammatory activities. These organometallic monocyclic β-lactams showed moderate in vitro antimicrobial activity against various standard microbial strains, including yeasts and Gram-negative and Gram-positive bacteria. Some compounds overcame the resistance of clinical Staphylococcus aureus isolates. Traditionally, monocyclic β-lactams target Gram-negative bacilli, but adding a ferrocene moiety and substituting the COOH group near the N-1 position with a non-ionizable ester group (COOR) extended their activity spectrum. The anti-inflammatory properties were assessed in macrophage-based models, revealing non-cytotoxicity below 10 μM. Two compounds were shown to be strong and selective arginase inhibitors, while five others effectively suppressed excessive NO formation without affecting basal NO production. The presence of a phenoxy group at C-3 of the β-lactam ring appeared to be crucial for selective NO inhibition. These hybrids did not scavenge NO but inhibited NO synthesis by suppressing iNOS expression. Overall, two novel hybrids were identified as promising hit candidates for treating infection-induced inflammatory reactions.

Underutilized edible Himalayan herb, Viola canescens Wall.; chemical composition, antioxidant and antimicrobial activity against respiratory tract pathogens

Understanding the intricacies of herbs and foods against bacterial infections is paramount for informed therapeutic choices. Delving into this domain, current study was focused to assess antimicrobial properties of Viola canescens organ specific extracts against prevalent respiratory tract pathogens (Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus pneumonia). Our methodology entailed proximate composition, TPC, TFC, Total condensed tannins and comprehensive chemical profiling by GC-MS, UPLC-PDA, and UPLC-MS/MS. Further, in-vitro, antioxidant potential through ABTS ֹ+ and DPPH ֹ radical scavenging assays was assessed. The root showed higher amount of proximate composition than its counterparts. Further, ethanol extract showed highest TPC (32.15±0.92mg GAE/g), TFC (125.61±2.28mg RE/g), and comparable TCT with methanol extract (34±0.19mg CE/g). UPLC analysis showed that p-coumaric acid was most predominant followed by rutin and luteolin among the V. canescens parts. In GC/MS analysis, methyl linoleate emerged as a major component as 10.70%, 17.62%, and 35.90% in flowers, leaves, and roots, respectively. Further, UHPLC- MS/MS data-based METLIN search revealed the presence of flavonoids, coumarins, terpenoids, and fatty acid derivatives etc. Chemo-metric analysis also showed variations of metabolites in different parts. All samples showed significant antioxidant activity with highest in methanol and ethanol flower extracts (0.037±0.001, 0.071±0.001 DPPHֹ and ABTS ֹ + IC50 mg/mL). The study suggested aerial parts can be a promising source of antioxidant and antimicrobial agents that may protect against respiratory tract pathogens similar to azithromycin. This substantiates the potential of V. canescens as a foundational ingredient for novel therapeutics.

Antimicrobial and degradable all-cellulose composite for functional and sustainable food packaging

The investigation of environmentally friendly and sustainable replacement materials is consistently prompted by the mounting environmental concern over plastics derived from petrochemicals. Compared with fossil oil derived chemicals and materials, cellulose is more readily available, less expensive, and biodegradable. Herein, all-cellulose composite films with excellent biodegradability and antimicrobial activities were prepared for sustainable food package. The all-cellulose films were prepared by a simple solution cast method of amino cellulose and carboxymethyl cellulose mixture. Rheological studies suggest typical non-Newtonian and shear thinning behavior of the all-cellulose solution associated with strong intermolecular electrostatic interactions. Such composite results in package films with amorphous structure, and uniform, dense and smooth morphology. Properties explorations indicated that the all-cellulose composites films exhibited better mechanical properties, water vapor and oxygen barrier properties than conventional synthetic plastic packages. Besides, the all-cellulose films showed excellent antimicrobial activity, and biodegradability. When applied as shrimp package, the all-cellulose composite films effectively extended shelf-life of shrimp by inhibition of microbial and oxidative deterioration of shrimp meat. This study provides a feasible approach to syntheze biodegradable and antimicrobial functional food package from cellulose in replacing of traditional synthetic plastic films.

Implementation of Silver Nanoparticles Green Synthesized with Leaf Extract of Coccinia grandis as Antimicrobial Agents Against Head and Neck Infection MDR Pathogens.

Head and neck infections (HNI) associated with multidrug resistance (MDR) offer several health issues on a global scale due to inaccurate diagnosis. This study aimed to identify the bacteria and Candidal isolates and implement the silver nanoparticles green synthesized with leaf extract of Coccinia grandis (Cg-AgNPs) as a therapeutic approach against HNI pathogens. The Cg-AgNPs were characterized by the UV-visible spectrophotometer, FT-IR analysis, Zeta particle size, Zeta potential, and field emission scanning electron microscope (FESEM) analysis to validate the synthesis of nanoparticles. Additionally, the antimicrobial activity of Cg-AgNPs was presented by the zone of inhibition (ZOI), minimum inhibitory concentration (MIC), minimum bactericidal/fungicidal concentration (MBC/MFC), and antibiofilm assay. Moreover, the cell wall rupture assay was visualized on SEM for the morphological study of antimicrobial activities, and the in-vivo toxicity was performed in a swiss mice model to evaluate the impact of Cg-AgNPs on various biological parameters. Different bacterial strains (Staphylococcus aureus, Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa) and Candida sp. (Candida albicans, Candida tropicalis, Candida orthopsilosis, and Candida glabrata) were identified. The MIC, MBC, and antibiofilm potential of Cg-AgNPs were found to be highest against A. baumannii: 1.25 μg/ml, 5 μg/ml, and 85.01±5.19% respectively. However, C. albicans and C. orthopsilosis revealed 23 mm and 21 mm of ZOI. Subsequently, the micromorphology of the cell wall rupture assay confirmed the efficacy of Cg-AgNPs, and no significant alterations were seen in biochemical and hematological parameters on the swiss mice model in both acute and subacute toxicity studies. The green synthesized Cg-AgNPs have multifunctional activities like antibacterial, anticandidal, and antibiofilm activity with no toxicity and can be introduced against the HNI pathogens.

Tunable photoluminescence of electrosynthesized Ag2S@ZnSe quantum dots for nanomedicine applications

Quantum dots (QDs) synthesized from environmentally friendly precursors associated to scalable and high-efficiency production routes are essential for nanomedicine applications. Ag2S nanocrystal is notable by antimicrobial activity, photothermal properties, and low toxicity, making it promising bioactive nanomaterial. In this work, L-glutathione (GSH) capped Ag2S and ZnSe QDs were synthesized by using a fast and environmentally friendly electrochemical method (cavity cell, graphite powder macroelectrode and aqueous medium) and tested for biological applications. Ag2S nanocrystals presented a monoclinic structure (XRD analysis). The modulation of the optical properties was carried out by varying the Ag+/S2- ratio (1:1, 2:1, and 4:1), showing a photoluminescence hypsochromic shift from 916 to 759nm, respectively. The modulation of the optical parameters was also carried out by the synthesis of Ag2S@ZnSe core/shell nanostructures. ZnSe seeds were prepared by the same electrochemical method and added to the Ag2S solution followed by thermal treatment under reflux (10min). Ag2S@ZnSe systems showed higher photoluminescence intensity and a hypsochromic shift of the emission band using Ag2S cores (Ag+/S2- = 1:1 and 1:2), which was associated to the formation of alloy-type structures. In the case of the Ag2S@ZnSe (Ag+/S2- = 1:4), a bathochromic shift of the emission bands can be observed, which was associated to the formation of a core/shell structure. Ag2S@ZnSe QDs were tested in antimicrobial and cytotoxicity assays, showing a minimal inhibitory concentration (MIC) equal to 512µg.mL-1. No cytotoxicity was observed against the Vero cell line at all concentrations tested (7.81 to 1000µg.mL-1), and low cytotoxicity against the HT-29 tumor line (7.81 to 31.25µg.mL-1), thus showing promising results for bioapplications.