Gram-positive Bacterial Strains Research Articles

Engineering of self-assembled silver-peptide colloidal nanohybrids with enhanced biocompatibility and antibacterial activity

Several bacterial strains have developed resistance against commercial antibiotics, and interestingly, supramolecular nanomaterials have shown considerable advantages for antibacterial applications. However, the main challenges in adopting nanotechnology for antibacterial studies are random aggregation, compromised toxicity, multi-step preparation approaches, and unclear structure-function properties. Herein, we designed the amphiphilic tripeptide that acts as a reducing and capping agent for silver metal to form silver-peptide colloidal nanohybrids with the mild assistance of UV light (254 nm) through the photochemical reduction method. The nanohybrids are characterized by different spectroscopic and microscopic techniques, and non-covalent molecular interactions between metal and peptide building blocks confirm their central role in the formation of nanohybrids. The tripeptide is biocompatible and can reduce the toxicity of silver ions (Ag+) by reducing to Ag0. These colloidal nanohybrids showed antibacterial activity against gram-negative and gram-positive bacterial strains, and the possible mechanism of killing bacterial cells could be membrane disruption. This synthetic strategy is facile and green, which helps avoid using toxic chemicals or reagents and complicated methods for colloidal nanohybrid preparation for biomedical applications.

Investigating antibacterial and anti-inflammatory properties of synthetic curcuminoids

The concept of intratumoral microbiota is gaining attention in current research. Tumor-associated microbiota can activate oncogenic signaling pathways such as NF-κB, thereby promoting tumor development and progression. Numerous studies have demonstrated that curcumin and its analogs possess strong antitumor effects by targeting the NF-κB signaling pathway, along with potent antibacterial properties. In this study, we tested the antibacterial activity of two curcuminoids, Py-cPen and V-cPen, against the Gram-negative bacterial strains Pseudomonas aeruginosa and Escherichia coli and the Gram-positive bacterial strain Streptococcus aureus using in vitro assays and fluorescent microscopy. We observed that both Py-cPen and V-cPen reduced NF-κB activation upon lipopolysacharide (LPS) challenge in cell assays. In addition, our findings indicate that Py-cPen and V-cPen interact with LPS, as demonstrated by transmission electron microscopy and confirmed using in silico analyses, thereby modulating LPS activity. Overall, our data indicate that Py-cPen and V-cPen exhibit strong antibacterial and antiinflammatory properties, suggesting their potential as candidates for new multitarget therapeutic strategies.

Investigation of antibacterial and anticancer activities of biosynthesized metal-doped and undoped zinc oxide nanoparticles.

Over the past 10 years, nanotechnology has emerged as a very promising technique for a wide range of biomedical applications. Green synthesized metal and metal oxide nanoparticles (NPs) are cheap, easy to produce in large quantities, and safe for the environment. Currently, efforts are being made to dope ZnO in order to improve its optical, electrical, and ferromagnetic qualities as well as its crystallographic quality. Actually, doping is one of the simplest methods for enhancing an NP's physicochemical characteristics because it involves introducing impure ions into the crystal lattice of the particle. In this study, the biosynthesis of zinc oxide NPs (ZnONPs) and metal-doped (Mg2+ and Ag+) ZnONPs was carried out by using aqueous and water-alcoholic extracts of Cynara scolymus L. leaves, Carthamus tinctorius L. flowers, and Rheum ribes L. (RrL) plant, which are rich in phytochemical content. Plant extracts act as a natural reducing, capping, and stabilizing agent in the production. The produced NPs were characterized using a variety of methods, such as ultraviolet-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), and scanning electron microscopy (SEM). The produced metal-doped and undoped ZnONPs exhibited characteristic absorption peaks between 365 and 383nm due to their surface plasmon resonance bands. SEM analysis revealed that the NPs were oval, nearly spherical, and spherical. In the FTIR spectra, the Zn-O bonding peak ranges from 400 to 700cm-1. The peaks obtained in the range of 407-562cm-1 clearly represent the Zn-O bond. In addition, the FTIR results showed that there were notable amounts of phenol and flavonoid compounds in both the prepared extract and ZnONPs. According to DLS analysis results, the size distribution of produced NPs is between 120 and 786nm. The antibacterial properties of green produced NPs on Gram-positive (Staphylococcus aureus RN4220) and Gram-negative (Escherichia coli DH10B) bacterial strains were investigated by agar well diffusion method. In studies investigating the anticancer activities of biosynthesized NPs, mouse fibroblast cells (L929) were used as healthy cells and human cervical cancer cells (HeLa) were used as cancer cells. Only the produced Ag-ZnONPs showed potent dose-dependent antibacterial activity (at concentrations higher than 100µg/mL) against Gram-positive and Gram-negative bacteria. RrL-ZnONP-600 and RrL-ZnONP-800 NPs produced with water-ethanol extract of RrL plant and calcined at 600 and 800°C were effective at high concentrations in healthy cells and at low concentrations in HeLa cancer cells, showing that they have the potential to be anticancer agents. The study's findings highlight the potential of green synthesis techniques in the production of medicinal nanomaterials for the treatment of cancer and other biological uses.

Biofabricated silver nanoparticles from Calotropis procera: A potential antimicrobial solution against pathogenic bacteria

Calotropis procera has the potential as a traditional medicinal plant that offers a diverse array of healing treatments. It was used in conventional medicine to remedy several ailments, including diarrhea and snakebites. This study examines the antibacterial properties of silver nanoparticles derived from the floral and latex components of C. procera. The nanoparticles were tested for their effectiveness against Gram-negative and Gram-positive bacterial strains. For characterization, the synthesized nanoparticles underwent thorough analysis using UV spectroscopy, fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). After the reduction process, the FTIR analysis revealed that some functional biomolecules found in plants form a coating on the nanoparticles, serving as organic agents that stabilize the nanoparticles. The size of nanoparticles analyzed with SEM falls in the 30 to 130 nm range. Furthermore, the synthesized silver nanoparticles were tested as antimicrobial agents against Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa, well-known microorganisms that can produce ulceration phases and severe health consequences. After a comprehensive examination, it was found that the silver nanoparticles have significant antibacterial effectiveness, particularly against S. aureus, a primary bacterium responsible for causing different ailments. The remarkable antibacterial efficacy of the silver nanoparticles synthesized in an environment-friendly manner underscores its potential applications in combating the evolution of antibiotic-resistant strains.

Facile modification of TiO2 as S-Scheme multifunctional materials for environmental protection and energy-storage applications

This paper reports a simple one-step modification of commercial TiO2 with a conducting polytrimethoxyslilypropyl aniline (PTMSPA, a polyaniline derivative having silyl networks) to have multi-functional (photocatalytic, optical, pseudocapacitive, hydrophobic, porous, antibacterial, and electromagnetic interference shielding (EMI)) properties and demonstrates associated applications. We present the S-Scheme heterojunction (SHJ) formation between TiO2 and PTMSPA through band position alignments and designate the resultant TiO2 - TiO2- based SHJ multifunctional materials as MF-TSSM. The internal electric field that is generated at the interface facilitates the transportation of the photogenerated electron transfer . The XRD pattern of MF-TSSM exhibits mainly the peaks of anatase TiO2. The TEM image of MF-TSSM indicates that the TiO2 particles are spherical in shape with sizes showing variations in diameters ranging from 60 nm to 250 nm depending on the experimental conditions of preparation and TiO2 particles are homogeneously distributed within the PTMSPA matrix. The optical energy band gap of MF-TSSM is 1.60 eV, a much lower value than PTMSPA (3.02 eV), suggesting that the composite formation between TiO2 and PTMSPA. The contact angle of MF-TSSM is significantly increased to 47.1 ° from 8.0 of TiO2, informing the increase of hydrophobic characteristics. The rate constant (k) for methylene blue photodegradation was 0.030 min-1, and 0.010 min-1 for MF-TSSM and pristine TiO2, respectively, The MF-TSSM composite exhibits a higher specific capacitance value (28.7 F/g) than TMSPA (21.1 F/g). At a frequency of 0.42 THz, MF-TSSM and PTMSPA exhibit return loss features indicating good EMI shielding performance. The MF-TSSM has been tested against two different Gram-positive and Gram-negative bacterial strains. The nanoparticles were evaluated at doses of 10, 20, 40, and 80 µg/ml. The results indicated that Klebsiella pneumoniae demonstrated a greater zone of inhibition, ranging from 9 mm at 10 µg/ml to 23 mm at 80 µg/ml, indicating increased susceptibility. Pseudomonas aeruginosa exhibited reduced inhibition zones, ranging from 10 mm at 10 µg/ml to 14 mm at 80 µg/ml, indicating increased resistance. The excellent effectiveness of MF-TSSM against various Gram-positive and Gram-negative pathogenic bacteria is explained by the interaction between reactive oxygen species and the cellular components of the bacteria as well the electrostatic interaction arising between positive charges in TMSPA and negative charges in the cell components, resulting in notable cytotoxicity and damage to the bacterial cells. The research underscores the capability of these modified TiO₂ nanoparticles in addressing bacterial infections, with efficiency differing by bacterial strain.

Structural and Biological Comparative Studies on M(II)-Complexes (M = Co, Mn, Cu, Ni, Zn) of Hydrazone-s-Triazine Ligand Bearing Pyridyl Arm

The molecular and supramolecular structures of some M(II) complexes (M = Co, Mn, Cu, Ni, Zn) with a hydrazone-s-triazine ligand (BMPyTr) were discussed based on single crystal X-ray diffraction (SCXRD), Hirshfeld and DFT analyses. A new Co(II) complex of the same ligand was synthesized and its structure was confirmed to be [Co(BMPyTr)Cl2]·H2O based on FTIR and UV–Vis spectra, elemental analysis and SCXRD. The geometry around Co(II) was a distorted square pyramidal configuration (τ5 = 0.4), where Co(II) ion is coordinated to one NNN-tridentate ligand (BMPyTr) and two Cl- ions. A Hirshfeld analysis indicated all potential contacts within the crystal structure, where the percentages of O⋯H, N⋯H, C⋯H, and H⋯H contacts in one unit were 11.2, 9.3, 11.4, and 45.9%, respectively, while the respective values for the other complex unit were 10.3, 8.8, 10.6, and 48.0%. According to DFT calculations, the presence of strongly coordinating anions, such as Cl-, in addition to the large metal ion size, were found to be the main reasons for the small M-BMPyTr interaction energies in the cases of [Mn(BMPyTr)Cl2] (260.79 kcal/mol) and [Co(BMPyTr)Cl2]·H2O (307.46 kcal/mol) complexes. Interestingly, the Co(II) complex had potential activity against both Gram-positive (S. aureus and B. subtilis) and Gram-negative (E. coli and P. vulgaris) bacterial strains with inhibition zone diameters of 13, 15, 16, and 18 mm, respectively. Also, the new [Co(BMPyTr)Cl2]·H2O (IC50 = 131.2 ± 6.8 μM) complex had slightly better cytotoxic activity against HCT-116 cell line compared to BMPyTr (145.3 ± 7.1 μM).

Antibacterial profile and antiproliferative activities over human tumor cells of new silver(I) complexes containing two distinct trifluoromethyl uracil isomers

New silver(I) complexes of 5-(trifluoromethyl)uracil (5TFMU) and 6-(trifluoromethyl)uracil (6TFMU) isomers were synthesized, characterized, and evaluated as antibacterial and antiproliferative agents. Based on elemental and thermogravimetric analyses, the Ag-5TFMU and Ag-6TFMU species are formulated as AgC5H2F3N2O2 and Ag2C5HF3N2O2, respectively. Infrared and 13C solid-state nuclear magnetic resonance spectroscopies suggest coordination of the trifluoromethyluracil isomers to silver by both nitrogen and oxygen atoms. Confirmation of their structure and connectivity was achieved, in the absence of single crystals of suitable quality, by state-of-the-art structural powder diffraction methods. In Ag-5TFMU, the organic ligand is tridentate and two distinct metal coordination environments are found (linear AgN2 as well as C2v AgO4 geometries), whereas Ag-6TFMU contains a complex polymeric structure with tetradentate dianionic 6TFMU moieties and five distinct AgX2 (X = N, O) fragments, further stabilized by ancillary (longer) Ag…O contacts. These species presented modest activity over Gram-positive and Gram-negative bacterial strains, whereas Ag-6TFMU was active over a set of tumor cells, with the best activity over prostate (PC-3) and kidney cell lines and selectivity indices of 4.6 and 1.3, respectively. On the other hand, Ag-5TFMU was active over all considered tumor cells except MCF-7 (breast cancer). The best activity was found for PC-3 cells, but no selectivity was observed. The Ag-5TFMU and Ag-6TFMU species also reduced the proliferation of tongue squamous cell carcinoma cell lines SCC − 4 and SCC-15. Preliminary biophysical assays by circular dichroism suggest that the Ag-5TFMU complex interacts with DNA by intercalation, an effect not seen in Ag-6TFMU.

Bio-synthesized AGS@AgNPs for wound healing, antioxidant support, antibacterial defense, and anticancer intervention

Slow wound healing and wound infections are significant challenges for burn patients. Biosynthesis of nanoparticles (NPs) using plant extracts offers a rapid, facile, and safe method for producing biocompatible NPs. In this study, Anethum graveolens seed (AGS) extract served as a masking and reducing agent for the synthesis of silver nanoparticles (AGS@AgNPs). Initially, the parameters influencing AGS@AgNPs synthesis, including silver nitrate concentration, reaction time, temperature, and pH, were optimized. Subsequently, AGS@AgNPs structural and biological characteristics were evaluated. Observation of the surface plasmon resonance (SPR) of the AGS@AgNPs at approximately 420 nm, accompanied by a color change of the suspension to dark brown, confirmed AGS@AgNPs synthesis. Analysis via X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), zeta potential, and transmission electron microscopy (TEM) confirmed the production of pure, homogeneous, spherical, and stable silver NPs with sizes ranging from 20 to 40 nm using Anethum graveolens extract. Antibacterial assays revealed significant activity against both Gram-positive and Gram-negative bacterial strains. Antioxidant assessments demonstrated that AGS@AgNPs at a concentration of 250 μg/ml exhibited 92% inhibition of DPPH free radicals and in FRAP test, A. graveolens seed extract and AGS@AgNPs reduced Fe3+ ions to Fe2+ by 48.7% and 73.1%, respectively. Investigation of anticancer properties against the lung cancer cell line (A-549) revealed an IC50 value of 242 μg/ml. The results of the flow cytometry test and lactate dehydrogenase (LDH) assay demonstrated the death of cancer cells. Moreover, wound healing assays demonstrated a significant acceleration in burn wound closure rates in rats on days 3, 7, and 14 following treatments with AGS@AgNPs. Overall, these findings highlight the favorable biological activities of AGS@AgNPs, suggesting their potential utility in nanomedicine applications.

Synthesis, characterization, antibacterial, antioxidant and molecular docking studies of Zn(II) complexes with imine quinoline derivative ligand

The efficacy of metal complexes with bioactive ligands for pharmaceutical purposes is increasingly gaining clinical and commercial importance for treating infectious diseases. This research aimed to synthesize new Zn(II) complexes, assess their potential applications in antibacterial and antioxidant properties, and explore their molecular docking properties. The synthesis was done by condensing 7-chloro-2-hydroxyquinoline-3-carbaldehyde and 2,2′-thiodianiline with Zn(II) metal complexes. A range of spectroscopic techniques, such as 1H and 13C NMR, FTIR, TG/DTA, pXRD, and UV–Vis, were employed to characterize both the ligand and its complexes. Imine quinoline ligand (L), ZnL, and ZnL2 all had average crystallite diameters of 13.28, 21.19, and 16.26 nm, respectively, according to pXRD analysis, which confirmed that the synthesized ligand and its Zn(II) complexes showed polycrystalline properties. Based on the results, an octahedral geometry was proposed for the complexes. A very good agreement was obtained between the experimental and the TD-DFT calculated absorption peaks. Their biological potency against Gram-positive (Staphylococcus aureus ATCC 25926) and Gram-negative (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 248) bacterial strains as well as antioxidant properties were tested. The ZnL complex showed a maximum growth inhibition of 9.50 ± 0.41 mm against S. aureus ATCC 25926; whereas the maximum growth inhibition of the ZnL2 complex was 9.67 ± 0.47 mm and 9.33 ± 0.47 mm against ATCC 25926, respectively. With an IC50 of 167.3 ± 1.04 mg/mL, ZnL had the strongest antioxidant activity against DPPH radicals. All the complexes had strong binding affinities according to the molecular docking investigation: L (−11.31 kcal/mol), ZnL (−11.38 kcal/mol), and ZnL2 (−13.51 kcal/mol) against the active sites of S. aureus and (−7.92, −8.07, and −8.92) kcal/mol, respectively, against the active sites of E. coli. The Zn(II) complexes had the highest potency of biological activity.

Novel Co(II), Cu(II) and Zn(II) complexes derived from thiazole containing Schiff base ligands: Green synthesis, antimicrobial and anti-cancer studies

Six novel metal complexes of Co(II), Cu(II), and Zn(II) were synthesized using a microwave-assisted method. These complexes were derived from Schiff base ligands prepared through the condensation of 4-(p-fluorophenyl)-5-methyl-2-aminothiazole with 3-methoxysalicyldehyde (L1) and 2-hydroxynaphthaldehyde (L2). Characterization techniques, including UV–vis, IR, NMR, and HR-MS confirm the tridentate nature of Co(II), Zn(II), and bidentate nature of Cu(II) complexes. Elemental and thermogravimetric analysis showed 1:2 (M: L) stoichiometry in metal complexes. Meanwhile, magnetic susceptibility and powder X-ray diffraction express the geometry and crystal systems of complexes. The antimicrobial analysis of the synthesized compounds indicates Cu(II) complexes have greater potency against gram-positive bacterial and fungal strains while Zn(II) complexes show a greater zone of inhibition against gram-negative bacterial strains. Moreover, MIC values of the most potent complexes [Cu(L2)2] and [Zn(L2)2] range from 190-375 µg/mL. Furthermore, ligands and their complexes have been tested for anticancer potential against MDA-MB 231 and A549 cell lines by MTT assay. [Zn(L1)2] and [Zn(L2)2] complexes were found to have potent activity with IC50 values of 16.7 µM, 24.1 µM, and 8.7 µM, 13.4 µM respectively on MDA-MB-231 and A549 cell lines compared to other complexes and parent ligands. Molecular docking study performed using the PyRx 0.8 (with RF-Score V2 scoring function) program against EGFR (PDB: 5XGM) showed strong binding interactions which supports the experimental results.

Green synthesis and antibacterial potency of Ag/CuO/ZnO nanoparticles derived from Psidium guajava L. extracts

Nanoparticles, characterized by their unique physicochemical properties, represent a significant frontier in interdisciplinary research, particularly within the realms of biomedicine and environmental science. This investigation delves into the eco-friendly synthesis of silver (Ag), copper oxide (CuO) and zinc oxide (ZnO) nanoparticles utilizing extracts derived from Psidium guajava L. The utilization of these botanical extracts presents a sustainable alternative to traditional nanoparticle fabrication methodologies, aligning with global sustainability imperatives and fostering environmentally conscious practices. The escalating global nanoparticle market, valued at over $30 billion in 2020 and projected to surpass $90 billion by 2027, underscores the economic significance and industrial relevance of nanoparticle research. This research trajectory fuels innovation across a spectrum of sectors, including healthcare, cosmetics and environmental remediation. The commercialization of nanoparticle-based products not only drives substantial revenue streams but also catalyzes advancements in research, development and manufacturing endeavors. Drawing upon aqueous extracts sourced from P. guajava., leaves and fruits, this study capitalizes on their inherent phytochemical composition to serve as stabilizing, reducing and capping agents during nanoparticle synthesis. Employing state-of-the-art characterization techniques such as UV-Vis spectroscopy, FTIR spectroscopy, FE-SEM and EDS facilitates a comprehensive analysis of the synthesized nanoparticles' physicochemical attributes. Assessment of the nanoparticles' antibacterial efficacy against gram-positive (Bacillus subtilis, Staphylococcus aureus) and gram-negative (Escherichia coli, Proteus vulgaris) bacterial strains reveals compelling results. Minimum inhibitory concentrations (MIC) elucidate notable efficacy, notably against P. vulgaris (3.75 mg/mL), S. aureus (7.5 mg/mL) and B. subtilis (10 mg/mL and 12.5 mg/mL), indicative of their potential biomedical applications in combating microbial infections.

Antibacterial and Cell-Viability of Hydroxyapatite Derived from Waste Marine Shell for Biomedical Applications

The present study discusses on the functional groups, structural characterization and thermal behaviour of Crassostrea angulata shell used for the synthesis of a biocompatible hydroxyapatite material. The hydroxyapatite was synthesized from C. angulata shell through precipitation method and characterized using XRD, FTIR, FE-SEM, EDX mapping, HR-TEM and SAED pattern. The formation of hydroxyapatite was confirmed from the high intense X-ray diffraction lines and by the presence of chemical groups such as PO43–, OH– and CO32–. The structural changes during the formation of hydroxyapatite from the thermal decomposition of C. angulata shell were studied through XRD and TG-DTA. The morphology study by FE-SEM indicates that the synthesized hydroxyapatite materials were in the form of clusters of rod-like particles. The SAED patterns and XRD spectral lines confirmed the crystalline nature of the synthesized hydroxyapatite. The antibacterial activity and cell viability assay of prepared hydroxyapatite were studied to assess its suitability in various biomedical applications. The antibacterial activity of hydroxyapatite was assessed against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus saprophyticus) bacterial strains. The cytocompatibility of hydroxyapatite was assessed through an MTT assay using osteoblast cells (MG-63 cell). Thus, the prepared hydroxyapatite shows good antibacterial action and cell viability nature and it can be applied in various biomedical applications.

Formulation and Evaluation of Antibacterial and Anti-Inflammatory Emulgel Containing Eugenia caryophyllus Buds Extract

ABSTRACT: Background: Eugenia caryophyllus is a valuable aromatic spice used in household cooking. Traditional healers frequently employ the plant, which is said to have therapeutic qualities, in herbal concoctions to treat a variety of illnesses and conditions. Objective: Eugenia caryophyllus clove buds have antibacterial, analgesic, and anti-inflammatory properties. The formulation of clove emulgel and its assessment using a variety of evaluation criteria were the main objectives of the current study. Clove emulgel was evaluated for its anti-inflammatory and anti-microbial properties. Materials and Procedures: We extracted and assessed the oils from Eugenia caryophyllus buds for phytochemical testing using solvents such as methanol, ethanol, petroleum ether, and N-hexane. We prepare emulgel and test it for spreadability, pH, and other organoleptic characteristics. We used egg albumin denaturation as a protein to measure the in vitro anti-inflammatory efficacy. We tested the antibacterial susceptibility using the agar-well diffusion method. Results: Alkaloids, saponins, tannins, steroids, carbohydrates, and glycosides were the phytochemical components found in clove bud extract. Physical factors such as color, consistency, and state—such as semi-solid, smooth, and brownish-gummy—are included in this category of evaluation parameters. The emulgel's pH was 5.35, its spreadability ranged from 1.6 to 2.5 cm, and no phase separation was noticed while the emulgel was stored. An in vitro anti-inflammatory test (spectroscopy method) and an antimicrobial test (zone of inhibition) were used to evaluate the anti-inflammatory activity of emulgel. Comparing clove oil emulgel to a typical medication, these evaluations found that it demonstrates strong anti-inflammatory and antibacterial resistance. Conclusion: In conclusion, Clove Buds Emulgel has demonstrated antibacterial activity against both gram-positive and gram-negative bacterial strains. Emulgel demonstrated the inhibitory response percentage in relation to the standard. This validates the roles that E. caryophyllus has been shown to play in protecting human health. This innovative emulgel mixture was applied to arthritis to lessen microbial infection and joint discomfort. In addition, more preclinical and clinical trials will be needed for this research in order to successfully commercialize the emulgel formulation for the treatment of inflammation and antimicrobial activity.

Ultrasonic-aided preparation of poly(vanillin-co-thiophene)/green Fe₃O₄ nanocomposites via solution mixing for methyl orange adsorption and antibacterial applications

This work describes the preparation of novel nanocomposite materials comprising a newly synthesized semiconducting copolymer, poly(vanillin-co-thiophene) (PVTH), blended with different weight proportions (3 %, 6 %, and 9 % by weight) of greenly synthesized magnetite nanoparticles (GFe3O4 MNPs) via solution mixing, assisted by ultrasonic irradiation. PVTH copolymer was synthesized through the polycondensation of vanillin, a bioderived aldehyde, and thiophene, catalyzed by sulfuric acid. GFe3O4 MNPs were prepared via the coprecipitation method with mint extract as an environmentally friendly stabilizer. The physicochemical properties of the prepared samples were investigated by 1H NMR, 13C NMR, FTIR, XRD, UV–vis, TGA, FE-SEM/Eds, AFM, VSM, tauc plot method and the four-points probe measurement. The samples were evaluated for two applications: methyl orange (MO) adsorption from aqueous solutions and antibacterial activities against Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and Bacillus) bacterial strains. The results showed that ultrasound irradiation facilitated the easy preparation of well-dispersed and homogeneous nanocomposites with combined semiconducting and magnetic properties and improved thermal stability compared to the parent PVTH. The most effective nanocomposite for MO removal was the sample containing 9 % GFe3O4 MNPs, whose adsorption behavior followed pseudo-second-order kinetics and Freundlich isotherm. Its maximum adsorption capacity was 103.79 mg g−1. In addition, all samples showed antibacterial action against the tested bacterial strains, with PVTH showing the highest efficacy, followed by PVTH/GFe3O4 nanocomposites.

Adsorptive potential of dispersible chitosan-coated biogenic iron oxide nanocomposite for enhanced anti-bacterial activity against gram-positive and gram-negative bacterial pathogens

The use of various biomaterials, such as plants or microbes, to create nanoparticles (NPs), is seen as a viable strategy in green nanotechnology. The synthesis of low-cost, energy-efficient, nontoxic, ecologically acceptable metallic nanoparticles has recently become a critical topic. The biosynthesis of iron oxide NPs using pomegranate peel extract has been investigated. Biogenic iron oxide NPs were coated with highly porous chitosan as a supporting material to enhance applicability of NPs for wastewater remediation. Biogenic magnetic NPs and its composite were characterized by scanning electron microscope, X-ray diffraction, and Fourier Transformer Infrared spectroscopy (FTIR). Our study focused on the ability of biogenic magnetite Fe3O4 NPs and its bio-composite for removal of As+5 ions from wastewater. Adsorption isotherms were obtained using metal ion concentrations ranging from 5 to 25 mg/L. The Langmuir adsorption model was validated by our data. The reaction kinetics of the adsorption process were pseudo-second order. Interestingly, the bio-composite achieved 90% As+5 removal at pH4. In addition, the prepared nanocomposite was characterized using various analytical techniques to confirm its physicochemical properties. The adsorptive capacity of the nanocomposite was evaluated by studying the removal of pollutants and contaminants from aqueous solutions. Additionally, the antibacterial activity of the nanocomposite was assessed against a panel of clinically relevant Gram-positive and Gram-negative bacterial strains, including Staphylococcus epidermidis (RCMB 9241, ATCC 12228), Staphylococcus saprophyticus (RCMB 010028, ATCC 15305), Enterococcus faecalis (RCMB 010052), Streptococcus salivarius (ATCC 13415), Escherichia coli (RCMB 010052, ATCC 25922), Salmonella enterica serovar Typhimurium (RCMB 006(1), ATCC 14028) and Pseudomonas aeruginosa (ATCC 27853). Our findings have important implications in the field of low-cost, easy, and environmentally friendly water bioremediation.

Synthesis, Characterization and Antibacterial Activity Evaluation of CuO NPs and B-CuO NPs obtained from Livistona chinensis leaf extract.

Nanoparticles (NPs) exhibit fascinating size-dependent chemical and physical characteristics that make them useful for a variety of applications. The present paper reports the green synthesis of CuO NPs and B-doped CuO NPs (B-CuO NPs) from Livistona chinensis leaf extract. Not much work has been reported on the use of the plant extract for the fabrication of NPs, particularly those of Cu and its doped counterparts. Various spectroscopic techniques were used to characterize the synthesized NPs. In the FT-IR spectra, peaks obtained at 504 cm-1 to 600 cm-1 were due to Cu-O vibrations. The energy dispersive X-ray analysis (EDX) spectra confirmed the CuO NPs' composition and B's presence inside the NPs. The peak pattern in X-ray diffraction (XRD) spectrum confirmed the crystalline and monoclinic phases of the NPs. The average crystalline size of CuO NPs and B-CuO NPs was 19.56 nm and 17.30 nm respectively. The CuO and B-CuO NPs were tested against three Gram-positive bacterial strains namely Bacillus subtilis, Micrococcus luteus, and Staphylococcus aureus and three Gram-negative Escherichia coli, Salmonella abony, and Pseudomonas aeruginosa through Agar well diffusion method and it was found that CuO NPs showed higher activity than B-CuO NPs.

Unprecedented one-pot synthesis of 3,4-dihydropyrimidine-2-(1h)-ones catalyzed by hydrazine sulfate through Biginelli reaction, ADMET property, molecular docking studies and their antibacterial activity on Bacillus brevis and E. coli

The syntheses of 3,4-dihydropyrimidin-2(1H)-ones by one-pot, three-component condensation of aldehydes, β-ketoesters and urea or thiourea have been made more simple and efficient by using 20 mol% hydrazine sulfate as catalyst. Aldehydes, β-ketoesters and urea are cyclocondensed in the presence of hydrazine sulfate to produce dihydropyrimidines in ethanol under reflux conditions. The advantages of using hydrazine sulfate as a catalyst over the traditional Biginelli reaction conditions include outstanding yields (80–91%) and a shorter (10–15 hours) reaction time. In order to evaluate the antibacterial efficiencies of the synthesized compounds, we have studied the inhibitions of microbial proliferation of both Gram-positive (Bacillus brevis) and Gram-negative (E. coli) bacterial strains in comparison to a control group. The microbial inhibitions occur in the range of 40–98% by different derivatives of dihydropyrimidinones. Molecular docking studies of the synthesized compounds have also been done using software tools such as SwissADME.

Antibacterial and Healing Efficacy of Mangiferin-Loaded Silver Nanoparticle and Chitosan-Alginate Membrane Dressings

Mangiferin, a bioactive constituent of Mangifera indica (family Anacardiaceae), has an impressive therapeutic profile, having antioxidant, anti-inflammatory, analgesic, antibacterial, and immunomodulatory properties capable of possessing wound healing potential. Our investigation aims to isolate and characterize mangiferin, green synthesis of silver nanoparticles (Ag-NPs) and production of chitosan alginate (Cs/Alg) film dressing loaded with mangiferin Ag-NPs and assess antibacterial and wound-healing properties against infected excision and burn wounds. The isolated mangiferin was authenticated by estimating melting point, thin layer chromatography (TLC), fourier-transform infrared spectroscopy (FTIR), and high-performance liquid chromatography (HPLC). Ag-NPs were green synthesized and characterized by UV-visible, particle size, zeta potential (ZP), entrapment efficiency (%EE), scanning electron microscope (SEM), transmission electron microscope (TEM), and stability study. Chitosan alginate membrane dressing was prepared by incorporating mangiferin Ag-NPs, and film thickness, pH, film weight, water intake capacity, and in-vitro drug release parameters were estimated. Among the four mangiferin Ag-NP batches, MN3 formed stable polydispersity spherical Ag-NPs with smaller particle size and high %EE. Mangiferin-loaded Cs/Alg film MN-CM4 showed significantly higher (p < 0.001) drug content, wettability, release profile, and favorable pH changes. The mangiferin Ag-NPs embedded Cs/Alg film dressing showed a significantly high antimicrobial effect against the gram-positive bacterial strain of S. aureus, commonly found in wounds. MN3 and MN-CM4 treatment showed the shortest epithelialization period and enhanced wound closure. The hydroxyproline content has significantly (p < 0.001) increased, and myeloperoxidase content was reduced by MN3 and MN-CM4 treatment. MN-CM4 treatment showed complete re-epithelialization reduced inflammatory cells with thicker and denser collagen fiber deposition. The effectiveness of the Cs/Alg film of mangiferin Ag-NPs dressing has a synergistic effect on promoting speedy wound healing. The Cs/Alg film of mangiferin Ag-NPs showed rapid wound healing against infected and burned wounds, enhanced collagen synthesis, and anti-inflammatory and antibacterial efficacy.

Investigating the Efficacy of Various Natural Products in Raw Form against Multidrug-Resistant Bacteria.

The alarming increase in antibiotic resistance urges alternative and efficacious antimicrobial solutions. Historically, medicinal plants have been used for therapeutic purposes, such as relieving pain and healing wounds. However, the evaluation of the natural therapeutic effects of medicinal plants in a manner that resembles how humans typically consume them is lacking. Therefore, in this study, many medicinal plants known to have some antimicrobial effects, including Frankincense, Garlic, Myrrh, and Ginger, were evaluated for their direct antibacterial activity in raw form. The direct antimicrobial activity of medicinal plants was evaluated against a variety of Gram-positive and Gram-negative bacterial strains, such as Staphylococcus aureus (S. Aureus), Acinetobacter baumannii and Klebsiella pneumoniae using agar well diffusion method and turbidity measurements in suspension culture. Out of all the tested medicinal plants, only raw garlic (Allium sativum) powder, when dissolved in water or vinegar, offered a straightforward antibacterial activity. A combination of garlic extract and vinegar increased antibacterial activity. Aqueous garlic extracts displayed robust antimicrobial activity against many resistant bacteria. Other medicinal plants used in this study had absent or minimal antibacterial effects. Only garlic in its raw form was effective against antibiotic-resistant bacteria. The increase in the antibacterial activity of garlic when combined with vinegar suggests the synergistic activity of garlic. The straightforward antibacterial action of raw garlic may be strategically harnessed to combat the continuous challenge of increasing antibiotic resistance. This work promotes additional testing of more natural products (in raw form) and assesses their therapeutic effects clinically.

Carya Illinoinensis-mediated Green Synthesis and Antimicrobial Screening of Zirconium Oxide Nanoparticles: The Promising Antimicrobial Agent

Background: The synthesis of metal-based nanoparticles through conventional methods involves harsh conditions, high costs, and severe environmental threats. To overcome these issues, researchers are nowadays focusing on eco-friendly and low-cost methods for the synthesis of nanoparticles. Finally, several plant-mediated synthesis techniques have been developed, which have various advantages, such as low-cost, environmentally friendly, and easy application. The plant extract not only serves as a reducing agent but also plays a role as a stabilizing agent. The plantmediated synthesis provides new opportunities for cost-effective, environmentally-friendly nanoparticle synthesis with high dispersity and stability. Besides, bio-generated nanoparticles derived from plant extract have promising pharmacological applications, making them potential candidates for future medicines. Aims and Objectives: The current study aimed to synthesize zirconium oxide nanoparticles using Carya illinoinensis extract and examine their physicochemical properties. Additionally, the antimicrobial efficacy of these nanoparticles was evaluated against various pathogens, exploring their potential as potent antimicrobial agents. Method: The synthesized nanoparticles were analyzed and characterized by various techniques like UV-Vis spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Energy Dispersive X-ray spectroscopy (EDX). The UV-visible peak at 216 nm confirmed the formation of ZrO2 nanoparticles. The SEM images clearly showed that nanoparticles were spherical and relatively dispersed, with few agglomerations. The EDX spectra confirmed the existence of zirconium and oxygen as the basic constituents of the sample. TEM images demonstrated nanoparticles as spherical and uniformly dispersed but agglomerated with increasing precursor concentrations and decreasing nanoparticle dispersion. Fluconazole and gentamicin were used as standards in determining the antibacterial and antifungal activities of nanoparticles. Results: Considering the antifungal activity, a maximum zone of inhibition of 16 μg/ml was demonstrated in the case of 2 mM as compared to 4 mM and 6 mM concentrations. The Carya illinoinensismediated ZrO2 nanoparticles were screened against Gram-positive (S. aureus and P. aeruginosa) and Gram-negative (S. typhi and E. coli) bacterial strains. The fabricated nanoparticles exhibited promising action against all microorganisms. Conclusion: In the current study, zirconium oxide nanoparticles were synthesized by using Carya illinoinensis leaves extract as a reducing agent. The antifungal and antibacterial potential of the synthesized nanoparticles were evaluated. The green synthesis method used in this study is preferable to the others as it is more affordable, environmentally benign, and widely accessible.