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Developing safe and high efficiency contrast tools is an urgent need to allow in vivo applications of photoacoustics (PA), an emerging biomolecular imaging methodology, with poor invasiveness, deep penetration, high spatial resolution and excellent endogenous contrast. Eumelanins hold huge promise as biocompatible, endogenous photoacoustic contrast agents. However, their huge potential is still unexplored due to the difficulty to achieve at the same time poor aggregation in physiologic environment and high PA contrast. This study addresses both issues through the design of a biocompatible photoacoustic nanoprobe, named MelaSil_Ag-NPs, relying on silica-templated eumelanin formation as well as eumelanins redox and metal chelating properties to reduce Ag+ ions and control the growth of generated metal nanoparticles. This strategy allowed self-structuring of the system into a core-shell architecture, where the Ag core was found to boost PA signal, despite the poor eumelanin content. Obtained hybrid nanoplatforms, showed stable photoacoustic properties even under long irradiation. Furthermore, conjugation with rhodamine isothiocyanate allowed particles detection through fluorescent imaging proving their multifunctional potentialities. In addition, they were stable towards aggregation and efficiently endocytosed by human pancreatic cancer cells (BxPC3 and Panc-1) displaying no significant cytotoxicity. Such numerous features prove huge potential of those nanoparticles as a multifunctional platform for biomedical applications. Self-structuring of Silica-Eumelanin-Ag nanoparticles into a hybrid SiO 2 -Mel shell@Ag core architecture led to a huge improvement of photoacoustic signal. Unlabelled Image • Eumelanin photoacoustic properties are exploited to produce bioinspired photoacoustic nanoprobes. • In situ formation of silica-melanin‑silver leads to a self-structured hybrid nanoprobe. • Silver nanoparticles enhance intrinsic melanin photooacoustic signal. • Hybrid silica-eumelanin‑silver nanoprobes combine enhanced photoacoustic signal and high stability in biological media. [ABSTRACT FROM AUTHOR]

Nanostructured Ag@SiO 2 -Penicillin was synthesized from high-purity Ag0 NPs with a mean particle size of about 10 nm produced by electromagnetic levitation gas condensation (ELGC) method. The silver and penicillin contents of the synthesized nano-antibiotic were about 34 wt% and 2.5 wt% respectively, as determined by ICP-OES and TGA analyses. The antibacterial properties and synergistic effects of nanostructured Ag@SiO 2 and Ag@SiO 2 –Penicillin on killing the Methicillin-susceptible S. aureus (MSSA) and Methicillin-resistant S. aureus (MRSA) bacteria were also examined. The nanoparticles were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Ag@SiO 2 -Penicillin NPs showed an outstanding antibacterial activity compared to Penicillin and Ag@SiO 2 NPs. The Fractional inhibitory concentration (FIC) indexes were 0.54 and 0.52 against MSSA and MRSA bacteria respectively, illustrating the synergistic effects of Ag@SiO 2 -Penicillin NPs. In addition, Ag@SiO 2 -Penicillin NPs showed promising dose-dependent cytotoxicity effects indicating the protective effects emanating from anti-inflammatory properties of penicillin. • Ag@SiO 2 –Penicillin NPs have been prepared by cladding silver nano particles. • The prepared NPs have superior bactericidal properties against MSSA and MRSA compared to penicillin and Ag@SiO 2. • It is observed that the particles have significantly lower cytotoxicity than Ag@SiO 2. [ABSTRACT FROM AUTHOR]

The aim of the current study was to biosynthesize the silver nanoparticles (AgNPs) from the bacterial strain of Bacillus cereus (ATCC 14579) extracellularly. When bacterial extract was challenged with 1 mM silver nitrate (AgNO3) the color of the extract changed into brown confirms the formation of nanoparticles. These nanoparticles were capped with bovine serum albumin (BSA). UV- visible spectroscopy showed the absorption peak at 420 nm indicates the formation of AgNPs. Fourier Infra –red (FTIR) attenuated total reflection (ATR) spectroscopy showed amide and amine group associated with AgNPs that stabilizes the nanoparticles. Energy dispersive x-ray spectroscopy (EDX) showed a strong peak of silver confirms the presence of silver. Thermo gravimetric analysis (TGA) analysis was used to determine the protein degradation showed less protein degradation at higher temperature confirms the stability of nanoparticles. Transmission electron microscopy (TEM) showed the AgNPs are well dispersed and spherical, and 5.37 nm to 17.19 whereas albumin coated nanoparticles are size ranges from 11.26 nm to 23.85 nm. The anticancer effect of capped AgNPs (cAgNPs) showed the IC50 value against breast cancer MCF-7 at 80 μg/mL, intestinal colon cancer HCT- 116 60 μg/mL, and bone cancer osteosarcoma MG-63 cell line80 μg/mL while against normal fibroblast cells 3T3 cells showed the IC50 value at 140 μg/mL. Lactate dehydrogenase assay (LDH) showed higher toxicity on MCF-7, HCT-116, and MG-63 cells. The apoptotic study clearly showed the blebbing of membrane, chromatin condensation due to the production of reactive oxygen species (ROS) by ethidium bromide and acridine orange dual staining method. The DNA analysis showed the complete fragmentation of the DNA of treated cells when compared with control cells. Unlabelled Image • Bacillus cereus was used for the biosynthesis of silver nanoparticles (AgNPs). • AgNPs were capped with bovine serum albumin (cAgNPs). • cAgNPs showed high toxicity towards different cancer cells. • cAgNPs showed high release of lactate dehydrogenase. [ABSTRACT FROM AUTHOR]

In the present study, novel silver nanoparticles (AgNPs) were synthesized via a green method by using Forsythia suspensa fruit water extract. The synthesized AgNPs showed antibacterial activities against all the tested food-borne pathogens, including Listeria monocytogenes , Vibrio parahaemolyticus , Escherichia coli O157:H7, Staphylococcus aureus , Pseudomonas aeruginosa and Salmonella typhimurium. Furthermore, the S. aureus and V. parahaemolyticus were introduced as Gram-positive and Gram-negative model strains to explore the antibacterial mechanism of AgNPs. Minimal inhibitory concentrations (MICs) of V. parahaemolyticus and S. aureus were 6.25 μg/mL and 50 μg/mL, respectively, and the minimum bactericidal concentrations (MBCs) of V. parahaemolyticus and S. aureus were 12.5 μg/mL and 100 μg/mL, respectively. Results indicated that the AgNPs caused morphological alterations and damaged the membrane integrity of strains S. aureus and V. parahaemolyticus. In addition, the AgNPs induced the release of nucleic acids of V. parahaemolyticus cells, resulting in disrupting of cells reproduction. Unlabelled Image • A novel green synthesis method of silver nanoparticles based on Forsythia suspensa fruit was explored. • The silver nanoparticles showed good antibacterial activity against all tested food-borne pathogens. • The silver nanoparticles caused visualized morphological alterations of food-borne pathogens. • The silver nanoparticles damaged membrane integrity of food-borne pathogens. • The synthesized silver nanoparticles can induce the release of the nucleic acids of Vibrio parahaemolyticus. [ABSTRACT FROM AUTHOR]

The preparation of light-activated hybrid antibacterial agent combining the porphyrin molecules, bound to the silver nanoparticles (AgNPs) surface is reported. AgNPs were synthesized by N -methyl-2-pyrrolidone-initiated reduction without additional reducing agents. The chemical structure of protoporphyrin IX was modified with the aim to introduce thiol groups. The size distribution and shape features of AgNPs were checked using TEM and HRTEM microscopies. The introduction of thiol groups into the porphyrin was proved by IR spectroscopy. The AgNPs-porphyrin binding was performed in solution and confirmed by fluorescence quenching, Raman spectroscopy and energy-filtered transmission electron microscopy (EFTEM). The antibacterial tests were performed against S. epidermidis and E. coli upon to LED illumination and in the dark. The synergetic effect of AgNPs and porphyrin as well as light activation of the created antibacterial conjugates were observed. • The light-activated hybrid antibacterial agent combining the porphyrin and AgNPs is reported. • The chemical structure of porphyrin was modified for introduction of thiol groups, responsible for grafting to AgNPs • The antibacterial activity of prepared conjugates was tested on gram-negative and gram-positive bacterial strains. • The synergetic effect of AgNPs and porphyrin under illuminatwas observed. • The prepared hybrids show better antibacterial activity then the pristine porphyrin and AgNPs. [ABSTRACT FROM AUTHOR]

Endotracheal tubes (ETTs) are a common source of bacterial colonization, leading to ventilator-associated pneumonia (VAP). This research developed a biofilm-resistant ETT, following the principles of green chemistry. Using an aqueous layer-by-layer (LbL) technique, a thick polyelectrolyte multilayered film was deposited on a ventilation tube. The polyelectrolyte multilayered film accommodated silver nanoparticles (AgNPs) formed in situ by reducing Ag+ ions with Eucalyptus citriodora leaf extract. The multilayered film coating conformed to the curved surfaces of the ETT. Film thickness and silver content increased exponentially with the number of polyelectrolyte bilayer pairs, and a sufficiently high AgNPs content of 10–30%w/w was obtained at 75 to 125 bilayer films. Adhesion of the Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa was prevented by 99.9 and 99.99%, respectively, without cytotoxic effects against human lung epithelial cells (p < 0.05). Unlabelled Image • Antibacterial coating on endotracheal tubes was achieved using green methods. • Layer-by-layer technique was employed to deposit polyelectrolyte matrix. • Silver nanoparticles were formed inside the matrix using bio-reducing agent. [ABSTRACT FROM AUTHOR]

Continuous periodical monitoring of clopidogrel in physiological body fluids is indispensable in medical diagnosis of heart ailments and cardiovascular diseases. A highly sensitive electrochemical sensor has been fabricated with silver nanoparticles embedded chitosan-carbon nanotube hybrid composite (AgChit-CNT) as sensor interface for detection of the important anti-platelet drug, clopidogrel (CLP). Synthesized AgChit-CNT nanocomposite is examined by x-ray diffraction, Raman spectroscopy and field emission scanning electron microscopy for its chemical and structural characteristics. Crystalline silver nanoparticles of about 35 nm are well distributed in the composite and have formed continuous chain like linkages with CNTs all throughout. Electrochemical responses of the fabricated AgChit-CNT nanocomposite electrode for the determination of CLP have been examined by cyclic voltammetry and electrochemical impedance spectroscopy. The nanoAg patterned CNT nanocomposite interface acts as an excellent electron transfer mediator towards the oxidation of clopidogrel. Electrochemical determination of CLP was investigated by differential pulse voltammetry (DPV) and amperometric analysis under optimized conditions. The limit of detection by DPV and amperometry were 30 nM and 10 nM, respectively, and the time of the analysis is as low as 10 s. Practical applicability for determination in artificially prepared urine and pharmaceutical formulation has been examined with good recovery limits of 95.2 to 102.6%. Unlabelled Image • Silver nanoparticles are well seeded in the layer of chitosan over the surface of carbon nanotubes. • AgChit-CNT nanocomposite electrode applied to the electrochemical detection of clopidogrel, a vital antiplatelet drug. • Electrochemical behaviour of AgChit-CNT modified electrode towards clopidogrel well examined with various techniques. • Practical applicability of developed sensor has been test with real world samples of clopidogrel. [ABSTRACT FROM AUTHOR]

We synthesized silver nanoparticles using thirty Chinese plant extracts via a green synthetic strategy. UV–visible spectra showed that the silver nanoparticles have an absorbance at 450 nm. Among the thirty extracts, seven extracts (Cratoxylum formosum , Phoebe lanceolata , Scurrula parasitica , Ceratostigma minus , Mucuna birdwoodiana , Myrsine africana and Lindera strychnifolia) exhibited the successful synthesis of silver nanoparticles. These seven extracts showed higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reducing power than the other extracts. The silver nanoparticles synthesized using these seven extracts were mostly spherical with high colloidal stability. The cytotoxicity of these seven silver nanoparticle samples on human lung cancer cells (A549) was clearly higher than that of the extracts alone. Furthermore, the cytotoxicity was affected by the presence or absence of fetal bovine serum. Moreover, the cytotoxicity of the silver nanoparticles synthesized with Cratoxylum formosum and Mucuna birdwoodiana extracts resulted in apoptotic cell death in A549 cells. The wound healing activity observed by the cell scratch method on mouse fibroblast cells (NIH3T3) suggested that the Lindera strychnifolia extract produced silver nanoparticles with decent activity. These results provide ample and systematic information for researchers on the green synthesis of silver nanoparticles using plant extracts. Unlabelled Image • Thirty plant extracts are used for green synthesis of silver nanoparticles. • Synthetic process is totally green and eco-friendly. • Plant extracts play a role as a reducing and a stabilizing agent. • Silver nanoparticles exert biological activities. [ABSTRACT FROM AUTHOR]

The paper describes an innovative bio-design of some hybrid nanoarchitectures containing bioartificial membranes and silver nanoparticles phytogenerated by using a natural extract Caryophyllus aromaticus (cloves) that contains many bioactive compounds. Two kinds of liposomes with and without chlorophyll a (Chla) obtained through thin film hydration method were used to achieve bio- green -generated hybrids by a simple, cost effective bottom-up approach. The characteristic peaks of CE-nAg monitored by UV–Vis absorption have firstly demonstrated the biohybrids formation. The slightly blue shift and fluorescence quenching observed by fluorescence emission spectra highlighted the formation of hybrid systems by biointeraction between lipid vesicles and silver nanoparticles. The incorporation of silver nanoparticles in lipid vesicles resulted in significant changes of FT-IR spectra of liposomes, indicating a reorganization of biomimetic membranes. All the microscopic methods (SEM, AFM and TEM) confirmed the biosynthesis of "green" AgNPs together with associated biohybrids, their spherical and quasi-spherical shapes with nano-scaled size. By TEM assay it was shown that CE-nAg are surrounded by petal like cloud structures that consist of biopolymers like proteins or polysaccharides and other phytochemicals arising from clove extract. EDS spectra confirmed the formation of phyto-nanoAg and also the presence of silver in the biohybrids. In addition, Selected Area Electron Diffraction showed characteristic polycrystalline ring patterns for a cubic structure of the clove-generated AgNPs. The hybrid materials showed efficient physical stability, i.e. ξ value of −28.0 mV (for biohybrids without Chla, BH) and of −31.7 mV (for biohybrids labelled with Chla, Chla-BH), assured by strong electrostatic repulsive forces between particles. The "green" nano-silver particles (CE-nAg) showed remarkable antioxidant activity (AA = 90.2%). The biohybrids loaded with clove-AgNPs proved to be more effective, scavenging about 98.8% of free radicals (in case of Chla-BH), and of 92.6% (in case of BH). The antibacterial effectiveness showed that green AgNPs combine in a synergistic manner the antibacterial properties of clove extract with those of silver, resulting in an enhancement of inhibition diameter, by 20%. Chla-BH proved to be more potent against Escherichia coli, than BH, exhibiting an inhibition diameter of 42 mm. Regarding the in vitro cytotoxicity against tumour cells, the CE-nAg concentration significantly influenced the cell viability, i.e. IC 50 was 3.6% (v /v) for HT-29 cells. Chla-BH was more effective against HT-29 cancer cells at the concentrations ranging from 0 to 18% (v/v), when the normal cells were not affected. Clove -generated AgNPs exhibited haemolytic activity against hRBCs, while the biohybrids were haemocompatible. The action mechanism on the two cell lines (mouse fibroblast L929 cells and human colorectal adenocarcinoma HT-29 cells) investigated by fluorescence microscopy demonstrated that CE-nAg killed almost all the cells (94%) through necrosis at a concentration of 33.4% (v /v). The treatment of HT-29 cells with BH resulted in: 71.5% viable cells, 19.5% apoptotic and only 9% necrotic cells, while in the case of Chla-BH treatment, only 77.5% cells were viable, 16% cells were apoptotic and 6.5% were necrotic. In this way, the developed silver-based nanoparticles can represent viable promoters to develop new biohybrids with improved features, e.g. antioxidant and antibacterial effectiveness, haemolytic activity and greater specificity towards tumour cells. Unlabelled Image • 3D biohybrids based on biomimetic membranes and clove-nano-silver were designed. • AgNP biomodification with bioinspired membranes led to impressive bioperformances. • Biomaterials proved to be excellent antioxidant and antimicrobial agents. • Biohybrids exhibited antiproliferative activity against colorectal tumour cells. [ABSTRACT FROM AUTHOR]

Developing a non-toxic, super-absorbent and antibacterial hydrogel as a skin wound dressing is of significant importance. Sericin hydrogel is an ideal dressing material as it has excellent biocompatibility, biodegradability, moisture retention, high affinity to biomolecules, self-healing and promoting cell proliferation activity. Here, we blended silk sericin (SS) with poly(vinyl alcohol) (PVA) to prepare a SS/PVA hydrogel through repetitive freeze-thawing. The photoluminescence of SS/PVA hydrogel indicated PVA was well blended with sericin. SS/PVA hydrogel showed excellent hydrophilicity and swelling behavior for its porous structure. PVA blending effectively improved the thermostability of sericin and enhanced the mechanical property of sericin, but did not affect the crystallinity of sericin and PVA. SS/PVA hydrogel exhibited the ability to load and release small molecule drugs and silver nanoparticles. Cytotoxicity and immuno-toxicity assays suggested the gentamicin loaded SS/PVA hydrogel had excellent cytocompatibility on mammalian cells. Bacterial inhibition assay and wound infection model demonstrated the gentamicin loaded SS/PVA hydrogel could effectively inhibit bacterial growth, thus maintain cells viability. This novel hydrogel with antimicrobial activity has shown great potential in wound dressing. • We developed a simple, environmentally friendly method to prepare SS/PVA hydrogel with enhanced mechanical performance. • SS/PVA hydrogel had the ability of loading and releasing small molecule drugs and nanoparticles. • SS/PVA hydrogel loaded with gentamicin has excellent cytocompatibility and could effectively inhibit bacterial growth. [ABSTRACT FROM AUTHOR]

Abstract An improved active packaging system was developed for fresh fruits using silver nanoparticles (AgNPs) coupled with calcium alginate (Ca-ALG). For the synthesis of AgNPs aqueous, ethanol and methanol extracts of Artemisia scoparia (AS) were used. These AgNP's were characterized using UV–Vis, SEM, EDS, AFM, FTIR and gel electrophoresis. Ethanol extract of AS (ASE) produced AgNPs with smallest size in comparison to aqueous AS (ASA) and methanol extract of AS (ASM). AgNPs synthesized from ASE had a size range of 12.0–23.3 nm and were tested on Human Corneal Epithelial Cells to evaluate their cytotoxicity. At 0.05 ng/mL of AgNP's concentration, no toxic effects were observed on the evaluated cell line. Therefore, 0.05 ng/mL of AgNPs mixed with edible coating of Ca-ALG were applied on strawberries and loquats as active coating to increase their shelf life. Significant improvement was observed in the quality parameters of strawberries and loquats such as microbial analysis, acidity loss, soluble solid content loss, weight loss and quality decay. Ca-ALG coating incorporated with AgNPs enhanced the shelf life of strawberries and loquats in comparison to no treatment and simple Ca-ALG coatings. This study provides an insight to food industry to extend the shelf life of fresh fruits using AgNP's formulated coatings. Graphical abstract Unlabelled Image Highlights • Improved active packaging system for fresh fruits using AgNPs coupled with Ca-ALG. • Artemisia scoparia (AS) Waldst & Kit was selected as main reducing agent. • The AgNPs concentration of 0.05 ng/mL proves no toxic effects in evaluated cell line. • The AgNPs formulated active coatings enhance the shelf life of strawberries and loquats. [ABSTRACT FROM AUTHOR]

Abstract Silver nanoparticles (AgNPs) have great potential for their mechanistic role in biomedical researches. Recently, green biosynthetic approaches have been received much attention in plant science for nanoparticles production. Therefore, in the present study AgNPs have been synthesized utilizing in-vitro grown leaf extract of anti-diabetic medicinal plant Withania coagulans Dunal by the reduction of silver nitrate solution. W. coagulans synthesized silver nanoparticles (WcAgNPs) were characterized by UV–visible spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy, X-ray powder diffraction and Fourier transform Infra-Red spectroscopy. All cumulative results showed that WcAgNPs were ~14 nm in size having spherical shape with face centered cubic structure. High performance liquid chromatography confirmed the involvement of withanolides in AgNPs synthesis as a reducing/capping agent. Synthesized WcAgNPs showed greater antioxidative potential when compared with W. coagulans leaf extract. WcAgNPs have efficient antimicrobial potential and suppresses the growth of both gram positive and gram negative bacteria. In our finding we also observed cytotoxicity of WcAgNPs against SiHa (cervical cancerous, hyper-triploid) cell lines and apoptosis in SiHa cells after 48 hour incubation with 13.74 μg ml−1 (IC 50) concentration of WcAgNPs. As results suggested, this is the first report which explain that W. coagulans leaf extract have potential as bio-reducing agent for synthesis of silver nanoparticles, which can be exploited as anti-oxidant, antimicrobial and anti-cancerous agent and depicting an effective way for utilizing bioactive resources in restoration of medicinal properties of this plant with high efficacy. Graphical abstract Unlabelled Image Highlights • Reliable cost effective green synthesis of AgNPs using Withania coagulans • Synthesized AgNPs were spherical in shape and had size of 14 nm. • Bioactive compound withanolides were utilized during AgNPs synthesis. • AgNPs have antibacterial, antioxidant and cytotoxic (for SiHa cell lines) activities. [ABSTRACT FROM AUTHOR]

Abstract The present research work describes a novel method for green synthesis of silver nanoparticles using purple heart plant leaves extract, which is recognized as frequently found in households as an ornamental plant. The aqueous methanolic extract of purple heart plant leaves was prepared and employed in the synthesis of stable silver nanoparticles via biological reduction method. The purple heart plant leaves extract-mediated synthesized silver nanoparticles were systematically optimized using Box-Behnken design considering the effect of various independent variables (factors) like concentration of AgNO 3 , temperature and volume of purple heart plant leaves extract solution on the responses like particle size and polydispersity index of synthesized silver nanoparticles were optimized. Mathematical modelling was performed using quadratic polynomial model and response surface analysis was done to understand the factor-response relationship. The synthesized silver nanoparticles at optimum condition were found to be of spherical in shape under TEM with particle size of 98 nm and polydispersity index of 0.15. Optimized silver nanoparticles were further characterized through UV-VIS spectrophotometry, FTIR spectroscopy and TEM imaging studies. Also, the silver nanoparticles were evaluated for antibacterial activity on E. coli and S. aureus. In a nutshell, the studies construed successful synthesis of silver nanoparticles along with thorough understanding of the associated factors influencing their quality characteristics and significantly improved antibacterial activity as beneficial effect. Graphical abstract Unlabelled Image Highlights • Silver nanoparticles were synthesized using purple heart plant leaves extract. • These synthesized silver nanoparticles were optimized by Box-Behnken design. • Particle size and polydispersity index were investigated as response variables. • Optimized silver nanoparticles showed 98 nm particle size and 0.15 polydispersity index. • Optimized silver nanoparticles showed antibacterial activity against E. coli and S. aureus. [ABSTRACT FROM AUTHOR]

Abstract This project is focuses on novel, cost effective and simple plant mediated synthesis of silver nanoparticles (Ag-NPs) using leaf extract of Albizia procera. The optical, structural and physical properties of green synthesized Ag-NPs have been investigated by UV–Visible spectroscopy, X-ray Diffraction (XRD) and Atomic Force Microscopy (AFM), respectively. Prepared Ag-NPs are spherical in shape and crystalline in nature with an average size of 6.18 nm. Ag-NPs have showed promising potential in removal of organic pollutant methylene blue (MB) dye. Careful investigation on the removal of dye as a function of contact time, UV light and exposure time, dose of nanoparticles, temperature and pH have also been carried out. Moreover, Ag-NPs exhibit outstanding antibacterial activities against gram negative Escherichia coli (E. coli) and gram positive Staphylococcus aureus (S. aureus) bacterial pathogens. Graphical abstract Unlabelled Image Highlights • Cost effective facile synthesis of Silver Nanoparticles (Ag-NPs) using Albizia procera leaf extract is report first ever. • Ag-NPs are promising candidate for removal of organic pollutant Methylene Blue (MB) dye from textile industry wastewater. • Synthesized Ag-NPs can be effectively used as an antibacterial agent for different pathogens. [ABSTRACT FROM AUTHOR]

Abstract The green synthesis of biomaterials is of significant interest as it enables the safe and sustainable preparation of noble metallic nanoparticles for medical applications. Microalgae polysaccharides have received attention due to their outstanding properties such as biocompatibility, biodegradability and low cost. In addition, due to their variety of remarkable biological and physicochemical properties, polysaccharide-based nanoparticles have advantageous features yet to be explored. The primary objective of the current research was to investigate exopolysaccharides isolated from green microalgae Botryococcus braunii (EPBb) and Chlorella pyrenoidosa (EPCp), as both reducing and stabilizing agents, for the green synthesis of silver nanoparticles (AgNPs). Their antibacterial activity towards Gram-positive bacteria (Staphylococcus aureus), Gram-negative bacteria (Escherichia coli), and antibiotic-resistant bacteria (methicillin-resistant Staphylococcus aureus) was studied, as well as their cytotoxicity to human dermal fibroblasts. The presently synthesized AgNPs were spherical in shape and exhibited characteristic surface plasmon resonance at 430 nm. The main population had a particle size which ranged between 5 and 15 nm as analyzed by transmission electron micrographs. Zeta potentials averaged −51.81 ± 3.01 mV using EPBb and −12.16 ± 2.41 mV using EPCp. More importantly, AgNPs possessed strong antibacterial activity in a dose-dependent manner, even against drug-resistant bacteria. The enhanced antibacterial activity of these particles is explained due to extensive reactive oxygen species generation and bacterial cell membrane damage. In contrast, such AgNPs were not cytotoxic at the same therapeutic range to fibroblasts (0.5–10.0 μg/mL). In summary, these results showed that polysaccharide-capped AgNPs have a strong potential for numerous medical applications, such as antibacterial agents in pharmaceutical and biomedical areas. Graphical abstract (A) UV/Vis spectra and TEM micrographs of polysaccharide-capped silver nanoparticles, (B) growth curve and effect on the cell morphology of E. coli treated with the silver nanoparticles. Unlabelled Image Highlights • A new and useful application for exopolysaccharides from microalgae Botryococcus braunii and Chlorella pyrenoidosa. • Green and sustainable approach for the synthesis of silver nanoparticles based on the biorefinery from microalgae is highlighted. • Nanoparticles exhibited antibacterial activity towards Gram-positive, Gram-negative, and antibiotic-resistant bacteria. • The killing mechanisms involved in the observed antibacterial activity were investigated. • The polysaccharide capped‑silver nanoparticles were not cytotoxic to fibroblasts at the same therapeutic range. [ABSTRACT FROM AUTHOR]

Abstract Due to their remarkable antibacterial properties, silver nanoparticles (Ag NPs) and curcumin (CCM) have been widely used in the antimicrobial field. In our study, we have fabricated the uniform and stable silver/curcumin composite nanoparticles by a facile ultrasound treatment process and the synergistic antibacterial activity were evaluated. The curcumin not only played a role of reducing agent but also acted as a capping agent. The antibacterial effects of silver/curcumin (cAgNPs) were studied by measuring the growth curve and surface plate assay based on the E. coli and B. subtilis , which showed concentration dependent bacteriostatic and bactericidal effects of cAgNPs. The presence of CCM enhance the binding of Ag to bacterial membrane and Ag+ release in comparison to that without CCM, so that creating a temporary and local high Ag+ concentration near the surface of the bacterium, meanwhile, generation of more reactive oxygen species, lead to membrane damage, bacterial lipases and induce leakage of intracellular contents followed by bacterial death that lead to growth inhibition of the bacteria. The antibacterial effects were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the effect which were further found to decrease by introducing antioxidant N -acetyl- l -cysteine (NAC) act as a reactive oxygen species (ROS) scavenging agent. These initial data suggest that cAgNPs have a highly antibacterial efficient and might have potential to be developed as an effective antimicrobial nanomaterial. Highlights • Curcumin not only played a role of reducing agent but also acted as a capping agent; • Curcumin enhance the binding of Ag to bacterial membrane and Ag+ release; • Creating a temporary and local high Ag+ concentration near the surface of the bacterium; • Generation of more reactive oxygen species, lead to membrane damage, bacterial lipases and intracellular contents leakage. [ABSTRACT FROM AUTHOR]

Abstract In the present study, we report the preparation of antifungal and non-cytotoxic polymer nanocomposites with potential application in biomedical materials. Dodecanethiol-protected silver nanoparticles (AgNPs-DDT) were synthesized by a reduction/precipitation method and dispersed in chloroform to obtain stable colloidal dispersions. PBAT-based nanocomposites containing 0.25, 0.5 and 2 wt% AgNPs-DDT were prepared by casting method. The incorporation of AgNPs-DDT in PBAT matrix resulted in nanocomposites which combine improved mechanical performance and antifungal properties with a non-cytotoxic characteristic. Graphical abstract Unlabelled Image Highlights • Dodecanethiol-protected silver nanoparticles (AgNPs-DDT) were synthesized by a reduction/precipitation method. • Effect of AgNPs-DDT on the thermal, rheological and mechanical properties of PBAT-based nanocomposites was understood. • Antimicrobial and non-cytotoxic polymer nanocomposite was obtained. [ABSTRACT FROM AUTHOR]

Abstract Novel nanocomposite of Ag/AgCl and a single phase of anhydrous basic bismuth nitrate (ABBN)-Bi 6 O 4.46 (OH) 3.54 (NO 3) 5.54 with efficient antibacterial activity was prepared from BiOCl. Microstructure was characterized as AgCl nanotubes and Ag nanoparticles mixed with Bi 6 O 4.46 (OH) 3.54 (NO 3) 5.54 nanosheets in nanometer scale. Antibacterial activity of the composite was tested by agar disc diffusion and agar dilution methods using Escherichia coli as target bacteria. The diameter of inhibition zone of Ag/AgCl/ABBN is 17.0 mm while that of bulk BBN is 8.1 mm. The MIC value of Ag/AgCl/ABBN is ascertained as 35 μg mL−1. Results prove that Ag/AgCl/ABBN nanocomposite has much higher antibacterial activity in comparison with bulk basic bismuth nitrate. Graphical abstract Unlabelled Image Highlights • Ag/AgCl/ABBN nanocomposite is firstly prepared by a two-step method. • Superior antibacterial activity of the nanocomposite against E. coli. • Larger inhibition zone diameter of the nanocomposite than that of bulk BBN. • Bi 6 O 4.46 (OH) 3.54 (NO 3) 5.54 nanosheets are firstly formed. [ABSTRACT FROM AUTHOR]

Abstract Herein we present our research on generation of silver nanoparticles (AgNPs) on cellulose nanofibers by thermal treatment and DMF as reducing agents. The cellulose (CE) nanofibers were prepared by deacetylation of electrospun cellulose acetate (CA) nanofibers which were subsequently silver coated using AgNO 3 followed by thermal and DMF induced reduction processes. The samples were characterized with scanning electron microscopy (SEM), Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and antibacterial assays. Effect of these methods on mechanical properties, thermal stabilities (DTA analysis) and swelling of the CE nanofibers were also studied. Both the processes were effective and efficient in generation of AgNPs on CE nanofibers with higher contents and very good spatial distributions. The XRD, XPS and TEM results evidenced formation metallic AgNPs. TEM images depicted the CE nanofibers highly decorated with spherical AgNPs. The DMF induced process generated AgNPs with comparatively larger sizes. The antibacterial results confirmed excellent antibacterial performance of the CEAgNPs against S. aureus and E. coli. The CEAgNP nanofibers well decorated with AgNPs having good spatial distribution and excellent antibacterial performance suggests CEAgNPs as promising candidate for efficient antimicrobial activities. Graphical abstract Unlabelled Image Highlights • Synthesis of AgNP on cellulose nanofiber by heat treatment and DMF were studied. • Both the thermal treatment and DMF generated AgNPs with higher yields. • DMF induced method produced comparatively larger AgNP having higher contents on CE. • The CEAgNPs were highly effective against S. aureus and E. coli bacterial strains. • Small sized AgNPs generated by heat treatment showed better antibacterial activities. [ABSTRACT FROM AUTHOR]

Abstract A novel type of microcontainers based on hollow silver alginate microspheres and magnetite nanoparticles is reported as development of recently published technology. Magnetite nanoparticles were incorporated by two methods - co-precipitation with porous calcium carbonate during template formation and adsorption onto CaCO 3 particles or microcontainers' shell. Amount of magnetite loaded and microshells size (4.6 to 6.9 μm) were found to depend on the chosen method for magnetite nanoparticles incorporation. Stability of hollow microshells in saline, phosphate buffer and culturing media was studied. Microcontainers' susceptibility to magnetic field was investigated in solutions of varied viscosity, and their group movement velocity under constant magnetic field was evaluated by sequential optical microscopy imaging. Cell viability tests with prepared microshells were performed that demonstrated negligible cytotoxicity effect on human dermal fibroblasts cells. With HeLa cells moderate viability inhibition was found at high carriers:cells ratio at early time points which is attributed to more active and receptor-mediated endocytosis of carriers as well as known cytotoxicity of magnetite in some cancer cells. At 24 and 48 h time points HeLa cells proliferation fully recovers. Reported data opens perspectives for further biomedical-oriented studies and application of this novel kind of microcontainers with a number of techniques applicable for imaging, control and triggered cargo release provided by presence of silver and magnetite nanoparticles in the carriers and their suitability for further versatile functionalization by traditional LbL approach if needed. Highlights • In-situ loading of recently reported novel type of microcarriers with controlled amount and location of Ag and Fe 3 O 4 ; • Susceptibility of carriers to magnetic field in viscous media (resembling biological liquids such as blood, lymph) is shown; • No or moderate cytotoxic effect of microshells during first 12 h of incubation with full later recovery. [ABSTRACT FROM AUTHOR]

Abstract Biological synthesis involves the reduction and stabilization of metal ions using different types of organisms. Plants are an attractive source for silver nanoparticles (Ag NPs) synthesis because of their strong reducing potentials by production of a wide range of secondary metabolites. The present study describes the biosynthesis of Ag NPs using plant extract of Ocimum basilicum extract grown under in vitro condition for the first time. The surface Plasmon resonance found at 450 nm confirmed the formation of Ag NPs. FESEM images revealed relatively spherical- shaped of Ag NPs. The biosynthesized Ag NPs were crystalline in nature with mean diameter about 13.82 nm. FTIR results expounded the functional groups of plant extract responsible for the bio-reduction of silver ions and the interactions between them. The obtained nanoparticles showed good inhibitory activity against both Gram positive and Gram negative bacteria. These results suggest that with changes in plant's culture condition it may be possible to obtain nanoparticles with desired characteristics. Highlights • Biosynthesis of silver nanoparticles using plant extract of Ocimum basilisum grown in vitro • Characterization of biosynthesized Ag NPs by equipment • Identification of proteins, phenols and flavonoids as responsible plant metabolites in bio-reduction of Ag+ • Observation thin layer of biomolecules on the surface of the Ag NPs in FESEM images required for biocompatible function of Ag NPs • High antibacterial potential of Ag NPs [ABSTRACT FROM AUTHOR]

Abstract Silver nanoparticles (AgNPs) are widely explored to enhance the antibacterial property of medical devices such as wound dressings. However, no consensus has been reached on the efficacy and safety of AgNP incorporation. This study aimed (1) to elucidate the effect of proteins and inorganic ions on the antibacterial properties, (2) to confirm the antibacterial efficacy in vivo, and (3) to evaluate the wound healing ability of AgNPs incorporation into chitosan-based membranes. Three membranes with different amount of AgNPs were prepared. The antibacterial properties and silver release profile were evaluated after interacting with phosphate buffered saline or with serum in vitro. The antibacterial efficacy and the wound healing ability were explored in vivo. The results indicated that the biological environment had strong influences on the silver release: the inorganic ions resulted in a slow release whereas the proteins formed a barrier to block the silver release. Consequently, high amount of AgNPs incorporation was necessary to achieve in vivo antibacterial effects. Moreover, the addition of AgNPs did not alter the wound healing rate and tissue response. We can conclude that the AgNP incorporation can enhance antibacterial efficacy of biomaterials without altering the wound healing ability of the chitosan-based membranes. Graphical abstract Unlabelled Image Highlights • The inorganic ions can slow down silver release from silver nanoparticles (AgNPs). • Proteins can form a barrier to block silver release from AgNPs loaded materials. • AgNPs incorporation can enhance the antibacterial efficacy of biomaterials. • A high amount of AgNPs is necessary to achieve in vivo antibacterial efficacy. • AgNPs incorporation did not alter the wound healing rate and tissue response. [ABSTRACT FROM AUTHOR]

Abstract A novel series of silver-doped mesoporous bioactive glass/poly(1,8-octanediol citrate) (AgMBG/POC) elastomeric biocomposite scaffolds were successfully constructed by a salt-leaching technique for the first time and the effect of inclusion of different AgMBG contents (5, 10, and 20 wt%) on physicochemical and biological properties of pure POC elastomer was evaluated. Results indicated that AgMBG particles were uniformly dispersed in the POC matrix and increasing the AgMBG concentration into POC matrix up to 20 wt% enhanced thermal behaviour, mechanical properties and water uptake ability of the composite scaffolds compared to those from POC. The 20%AgMBG/POC additionally showed higher degradation rate in Tris(hydroxymethyl)-aminomethane–HCl (Tris–HCl) compared with pure POC and lost about 26% of its initial weight after soaking for 28 days. The AgMBG phase incorporation also significantly endowed the resulting composite scaffolds with efficient antibacterial properties against Escherichia coli and Staphylococcus aureus bacteria while preserving their favorable biocompatibility with soft tissue cells (i.e. , human dermal fibroblast cells). Taken together, our results suggest that the synergistic effect of both AgMBG and POC make these newly designed AgMBG/POC composite scaffold an attractive candidate for soft tissue engineering applications. Graphical abstract A novel silver-containing mesoporous bioactive glass/poly(1,8-octanediol citrate) (AgMBG/POC) elastomeric biocomposite scaffolds has been synthesized by salt-leaching technique for tissue engineering application. Unlabelled Image Highlights • AgMBG/POC elastomeric biocomposite scaffolds were developed by salt-leaching technique. • The incorporation of AgMBG into POC matrix improved water absorption and degradability of biocomposite scaffolds. • The viability of E. coli and S. aureus was significantly reduced by biocomposites. • Elastomeric biocomposites were biocompatible toward human dermal fibroblast cells. [ABSTRACT FROM AUTHOR]

Abstract The titanium (Ti) and its alloys have been widely used for dental and orthopedic implants. However, the Ti-based implants may suffer from bacterial infection, which would result in insufficient healing, implant failure and repeated surgical intervention. It is of great interest to inhibit the bacterial adhesion and colonization on the Ti-based implants by introducing proper surface coatings. In this work, a simple method was employed to synthesize the water-soluble catechol-containing chitosan (CACS). The CACS coatings can be deposited onto various substrate surfaces and exhibit substrate-independent behavior. The CACS-coated Ti surfaces were further deposited with silver nanoparticles (Ag NPs) via in-situ reduction of Ag+ ions using catechol moieties as the reducing agents. The resulting AgNPs/CACS-coated Ti surfaces exhibit antibacterial properties and can prevent the surface adhesion of bacterial cells, as evidenced by the inhibition zone test, live/dead bacterial staining assay and spread plate method. In addition, they show negligible cytotoxicity to L929 mouse fibroblast cells. Graphical abstract Unlabelled Image Highlights • A simple method for the synthesis of water-soluble catechol-containing chitosan (CACS) was reported. • CACS can be deposited onto various surfaces and its coatings exhibit substrate-independent behavior. • The CACS coating on Ti surfaces can be used to induce the in-situ reduction of Ag+ ions. • The Ag nanoparticles- and CACS-coated Ti surfaces exhibit good antibacterial properties with low cytotoxicity. [ABSTRACT FROM AUTHOR]

Abstract Zeolite/nanoparticle composites are synthesized and used as additive for waterborne formulations in replacement of traditional isothiazolinone-based biocides. Silver nanoparticles dispersed onto micrometer-sized crystals of A-type zeolite were prepared by thermal treatment or chemical reduction methods applied to the Ag-exchanged zeolite. The antifungal efficiency against Trichoderma sp. of waterborne outdoor coatings containing the supported silver nanoparticles, measured in terms of inhibition halo development, shows similar results to those obtained by using traditional organic biocides, the type, size and size distribution of the nanoparticles being the main factors affecting the biocidal action of the prepared coatings. Graphical abstract Unlabelled Image Highlights • Zeolite A as support allows the stabilization and noncohesion of nanoparticles. • Size and size distribution depend on the level of Ag+ loading in the solid. • The reduction method influences the nanoparticle nature. • Supported Ag nanoparticles could substitute toxic organic biocides. • Coatings containing the supported Ag nanoparticles showed biocidal activity. [ABSTRACT FROM AUTHOR]

Abstract Novel multifunctional composite poly(lactic acid) (PLA) films with alginate microbeads containing silver nanoparticles (AgNPs) were developed for potential antimicrobial food packaging applications. AgNPs, 10–20 nm in size, were synthesized in a Na-alginate solution by a hydrothermal method yielding a sterile, pH neutral colloid solution of low viscosity that was electrostatically extruded to produce Ag/alginate microbeads (190 μm in size) with retained AgNPs. Dried microbeads were uniformly dispersed in PLA films with retained AgNPs as confirmed by UV–Vis spectroscopy and scanning electron microscopy. The films were characterized regarding thermal and mechanical properties as well as silver release in different food simulants. Results show that PLA matrix served as a diffusion barrier so that the released silver concentration in water after 10 days was within the prescribed limit of 0.05 mg kg−1 while the films induced inhibitory effects against Staphylococcus aureus in the agar diffusion test. Highlights • Low viscosity Ag/alginate colloid solutions were produced by hydrothermal synthesis • Electrostatic extrusion yielded microbeads with preserved silver nanoparticles • PLA composite films containing Ag/alginate microbeads were made by solvent casting. • PLA matrix in composite films served as a diffusion barrier for silver release. • PLA composite films inhibited the growth of S. aureus at low silver release. [ABSTRACT FROM AUTHOR]

Abstract Infectious diarrhea caused by the food borne pathogen, Campylobacter jejuni , is a major threat to public health worldwide leads high incidence of child mortality each year. In the present study, hydrothermal synthesis of Silver-Graphene-TiO 2 nanocomposites along with TiO 2 , TiO 2 -Graphene and TiO 2 -silver nanocomposites was done and the samples were characterized using X-ray diffraction (XRD), tunneling electron microscopy (TEM) and UV–Vis Spectroscopy. Effect of silver and graphene addition on the broad spectrum antibacterial ability of TiO 2 was studied under visible light. Moreover, the effects on bacterial survival, membrane integrity, cellular motiltiy and biofilm formation of C. jejuni were also evaluated. A synergetic effect of silver and graphene on Silver-Graphene-TiO 2 nanocomposites was observed as indicated by its increased visible light sensitivity and enhanced antibacterial activity under visible light compared to its parent derivatives. Silver-Graphene-TiO 2 composites effectively reduced growth and caused leakage of protein and DNA from C. jejuni cell. Atomic Force Microscopy was used to confirm bacterial cell damage. Besides, it also reduced motillity, hydrophobicity and autoaggregation of C. jejuni and showed excellent inhibition of biofilm formation. Furthermore, no significant cytotoxicity of synthesized nanoparticles was observed in human cell lines. We propose that Silver-Graphene-TiO 2 composites can be used as effective antimicrobial agents to control the spread of C. jejuni by preventing both bacterial growth and biofilm formation. Highlights • Ag/Tio2-graphene nanocomposite was successfully prepared by hydrothermal method. • Ag/Tio2-graphene nanocomposite exhibited broad spectrum antibacterial activity. • The growth and motility of C. jejuni was reduced by the synthesized nanocomposite. • The nanocomposite decreased the hydrophobicity and auto aggregation ability of C. jejuni. • The nanocomposite showed excellent antibiofilm activity against C. jejuni. [ABSTRACT FROM AUTHOR]

Abstract Diagnosis of cancer by chemotherapy treatment, severe side effects caused by high dosages of cancer drugs include non-controlled cytotoxicity to bone marrow cells and immune cells. To overcome, we have synthesized nanoparticles with controlled sized hydroxyapatite (nHAp) materials doped and co-doped with silver and iron by co-precipitation, yielding materials that can treat both the infections and malignant tumors with non-cytotoxic nature to normal cells. Spherical and rod like morphologies were observed for the samples with higher Ag+ doping concentrations with average size of 50 ± 5 nm and (75 × 22) ± 5 nm2, whereas higher Ag+/Fe2+ co-doping concentrations yielded samples with spherical, rod-like, and flake-like structures. For samples nHAp and Ag+-nHAp samples were diamagnetic, whereas the Fe2+-nHAp and Ag+/Fe2+ co-doped samples were superparamagnetic. The in vitro biological toxicity study revealed that the Ag+/Fe2+-nHAp nanoparticles are effective for targeting to kill cancerous cells, for example, human cervical cancer (HeLa) cells efficiently while they are non-toxic to normal cells. Applying these nanoparticles for drug delivery system, 5-fluorouracil was loaded in the nanoparticles and studied its release kinetics. In the case of Ag+/Fe2+co-doped nHAp samples, a pulsatile drug release profile was observed, which the drug was released for about a week on varying the Ag+ and Fe2+ concentrations. The 5-fluorouracil release kinetics was well fitted by the first-order model with diffusion. Thus, nHAps co-doped with Ag+/Fe2+ material have the potential to lag the time on delivering the drug at site-specific could be with an application in biomedicine such as to treat malignant tumor without any bacterial side effect. Graphical abstract Unlabelled Image Highlights • We report the nHAp composites with Ag+ and/or Fe2+ ions for the treatment of malignant tumor without bacterial side effect. • Ag+/Fe2+co-doped nHAp are the efficient material with to kill the cancer cells while non-cyto-toxic toward normal cells. • Fe2+- doped and co-doped nHAp nanoparticles can be used to deliver at the targeted site using their magnetic property. • This paper presents a novel strategy that can be used a cost-effective route for biocompatible and drug release systems. [ABSTRACT FROM AUTHOR]

Abstract Innovative methods to detect and kill pathogenic bacteria have a pivotal role in the eradication of infectious diseases and the prevention of the growth of antibiotic-resistant bacteria. The combination of fluorescent carbon dots (FCDs) with silver nanoparticles (AgNPs) is an effective material for synergic detection and antimicrobial activity determination. However, the fluorescence quenching of the FCDs owing to an interaction with AgNP is a major limitation. In this study, we designed a system to utilize poly(vinylpyrrolidone) (PVP) and catechol chemistry (PVP@Ag:FCD) in order to avoid the fluorescence quenching of the FCD-AgNP combination due to Forster Resonance Energy Transfer (FRET). PVP@Ag:FCD exhibited bright fluorescence, which can be used for bacterial detection, through the promotion of electrostatic binding with the negatively-charged bacterial surface and generation of fluorescence quenching due to aggregation-induced quenching. Furthermore, the presence of silver nanoparticles in PVP@Ag:FCD produced an excellent bacteria killing efficiency against E. coli and S. aureus , even at low concentrations (0.1 mg/mL). In contaminated river water, the PVP@Ag:FCD system showed a simple, highly sensitive, and effective performance for both the detection and eradication of bacteria. Therefore, this system offers an auspicious method for the future detection and killing of bacteria. Graphical abstract Unlabelled Image Highlights • An FCD and AgNP-based material was designed for synergistic bacteria detection and killing. • PVP@Ag:FCD showed that our approach can avoid Ag-induced fluorescence quenching of FCD. • Fluorescence of PVP@Ag:FCD was quenched when treated with bacteria. • PVP@Ag:FCD showed a great bacteria killing efficiency against both E. coli and S. aureus. • This system offers promising strategy to combine biosensors with antibacterial activity. [ABSTRACT FROM AUTHOR]

Abstract Surface modification of Fe 3 O 4 nanoparticle with thiol groups was used for the immobilization of silver nano-particles to produce Fe 3 O 4 /SiO 2 -Pr-S-Ag NPs. The prepared catalyst was characterized by Inductively coupled plasma (ICP), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectrum (EDS), vibrating sample magnetometer (VSM) and Fourier transform infrared (FTIR) analysis. In this fabrication, thio-groups played an important role as a capping and stabilizing agent for Ag nanoparticles. Fe 3 O 4 /SiO 2 -Pr-S-Ag NPs show high catalytic activity as recyclable nanocatalyst toward degradation of 4-nitrophenol (4-NP), rhodamine B (RhB), and Methylene blue (MB) in the presence of NaBH 4 in water at room temperature. With the help of UV–Vis spectroscopy, catalysis reactions were examined. Furthermore, these reactions followed the pseudo-first order rate equation. Graphical abstract Unlabelled Image Highlights • Surface modification of Fe 3 O 4 nanoparticle with thiol groups were achieved. • Thio-groups played an important role as stabilizing agent for Ag nanoparticles. • Fe 3 O 4 /SiO 2 -Pr-S-Ag NPs show high catalytic activity for degradation of organic dyes. • The nanocatalyst can be magnetically recycled and reused. [ABSTRACT FROM AUTHOR]

Abstract Marine bio-resources are being widely studied as an invaluable source of compounds with therapeutic applicability. In particular, macroalgae contain an extended variety of bioactive compounds with different structures and promising biological applications. In this work, Ulva lactuca L. (hereafter UL) was utilyzed for the synthesis of gold and silver nanoparticles. Full characterization by UV–Vis spectroscopy, TEM, HRTEM and STEM miscroscopies, Z Potential and FTIR spectroscopy was performed. The first time in the scientific literature, the composition of carbohydrates of UL extract and their changes observed after nanoparticles synthesis were explored in order to investigate their possible role in the biosynthetic process. The reducing power, total phenolic content and DPPH scavenging activity of UL extract, Au@UL and Ag@UL nanoparticles were determined. The effects of UL extract, Au@UL and Ag@UL were tested in vitro on the colon cancer cell lines HT-29 and Caco-2, on normal primary neonatal dermal fibroblast cell line PCS-201-010, as well as on normal colon cell line CCD-112CoN. Lastly, the apoptotic activity and cellular uptake evaluation was determined for Au@UL and Ag@UL. Highlights • Aqueous extract of Ulva lactuca served to synthesize gold and silver nanoparticles. • The composition of the extract before and after the synthesis was determined. • This provided new information about the possible role of sugars during the synthesis. • The effects of UL extract, Au@UL and Ag@UL were tested in vitro on colon cancer cells. • Apoptotic activity and cellular uptake evaluation was determined for Au@UL and Ag@UL. [ABSTRACT FROM AUTHOR]

Abstract The paradigm modifications in the metallic crystals from bulky to micro-size to nano-scale have resulted in excellent and amazing properties; which have been the remarkable interests in a wider range of applications. Particularly, Ag NPs have much attention owing to their distinctive optical, chemical, electrical and catalytic properties that can be tuned with surface nature, size, shapes, etc. and hence these crystals have been used in various fields such as catalysis, sensor, electronic components, antimicrobial agents in the health industry etc. Among them, Ag NPs based disinfectants have paid attention due to the practical applications in our daily life. Therefore the Ag NPs have been used in different sectors such as silver-based air/water filters, textile, animal husbandry, biomedical and food packaging etc. In this review, the Ag NPs as a disinfectant in different sectors have been included in detail. Highlights • Silver nanoparticles as a potent disinfectant • Applications of silver nanoparticles in Environmental, HAIs and industrial sectors • Role of silver nanoparticles for disinfections [ABSTRACT FROM AUTHOR]

Abstract In this study, a high-performance biosensing nanoplatform based on amidoxime-modified polyacrylonitrile nanofibers decorated with Ag nanoparticles (AgNPs-PAN-oxime NFs) is described. The AgNPs-PAN-oxime NFs were prepared by the combination of electrospinning technique and chemical modification of nitrile group in the PAN. The proposed signal amplifiying nanoplatform was applied in the fabrication of an electrochemical aptasensor for the sensitive detection of CA 125 based on aptamer-cDNA duplex and target induced strand displacement recognition mechanism. The aptasensing interface offers high sensitivity and selectivity for detection of tumor marker due to inherent advantages such as high specific surface area of NFs, good conductivity by doping AgNPs into the polymer NFs and especially the ideal selectivity of anti CA 125 aptamer to its target. The electrochemical aptasensor revealed a wide dynamic linear range (DLR) from 0.01 to 350 U mL−1 with a correlation coefficient of 0.991 and limit of detection (LOD) of 0.0042 U mL−1. Additionally, the designed aptasensor showed acceptable selectivity, reproducibility, repeatability and stability. The satisfactory results for determination of CA 125 in serum samples compared to ELISA method (p -value > 0.05) indicated the potential application of aptasensor in clinical monitoring of tumor biomarker for early diagnosis and management of ovarian cancer. Graphical abstract Unlabelled Image Highlights • In this study, a high-performance biosensing nanoplatform based on amidoxime-modified polyacrylonitrile nanofibers decorated with Ag nanoparticles (AgNPs-PAN-oxime NFs) was introduced. • The described nanoplatform was utilized in a displacement electrochemical aptasensor for detection of CA 125 in ovarian cancer patients. • The electrochemical aptasensor revealed a wide dynamic linear range from 0.01 to 350 U mL-1 and a limit of detection of 0.0042 U mL-1. [ABSTRACT FROM AUTHOR]

Abstract A method was developed for the liquid exfoliation of molybdenum disulfide (MoS 2) from its bulk materials using ultrasound in aqueous phase with the assistance of chitosan (CS) and silver nanoparticles (Ag NPs) for effective loading of a variety of therapeutic molecules. The characterization results revealed that the as-made chemically-exfoliated MoS 2 nanosheets had an average thickness of ∼10 nm. The new material, CS and Ag NPs-modified MoS 2 (MoS 2 -CS-Ag), showed highly effective antifungal activities against Saccharomyces uvarum and Aspergillus niger. The Ag NPs-loaded MoS 2 nanosheets achieved outstanding antifungal effect by inhibiting fungal growth both in vitro and in vivo. Notably, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis of spore morphological changes caused by MoS 2 -CS-Ag treatment reveal that it may directly cause the cell death. The result of the analysis of the application of MoS 2 -CS-Ag as an antifungal for fruits also demonstrated the MoS 2 -CS-Ag protective properties against fungi. The excellent film-forming ability of CS has been shown to contribute to the effectiveness of MoS 2 -CS-Ag in preserving the freshness of fruits, exhibited in four chemical quality sections: Vc, total carbohydrate, weight loss, and titratable acidity in fruit preservation application assay. The present study reports a new and exciting insight in a multi-functional drug carrier for protecting postharvest fruit. Graphical abstract Unlabelled Image Highlights • Molybdenum disulfide nanosheets loaded with chitosan and sliver nanoparticles as a multi-functional antifungal material. • Molybdenum disulfide nanosheet showed highly effective antifungal activities against Saccharomyces uvarum and Aspergillus niger. • Molybdenum disulfide nanosheets applied in protecting postharvest fruit. [ABSTRACT FROM AUTHOR]

Abstract Silver nanoparticles (Ag NPs) have been deposited on powder P25 by a novel two-step method involving a precipitation reaction and atmospheric pressure dielectric barrier discharge (DBD) cold plasma treatment without the use of any environmentally and biologically hazardous reducing agents. The silver precursor is formed in the processing of precipitation reaction and then completely reduced to the metallic state by atmospheric pressure DBD cold plasma treatment as proved by X-ray photoelectron spectroscopy, UV–Visible absorption spectra and HRTEM analyses. TEM images indicate that the Ag NPs with average diameter of 3.7 nm were deposited on powder P25 with high dispersion although no reducing agents, stabilizers or surfactants were used. The prepared products show remarkable improvement for methylene blue (MB) photodegradation and effective inhibition of bacterias against Escherichia coli and Staphylococcus aureus. Highlights • A novel, efficient and eco-friendly stratege combining a precipitation reaction and DBD plasma treatment is introduced for the in situ reduction of Ag NPs on powder P25 surface. • The Ag NPs with average diameter of 3.7 nm were deposited on powder P25 with high dispersion without the use of environmentally and biologically hazardous reducing agents, stabilizers or surfactants. [ABSTRACT FROM AUTHOR]

Abstract Novel l ‑Arginine‑Dextran70 based-silver nanoparticles (SNPs) (SNPsArg), functionalized with Riboflavin (RF) and Human Serum Albumin (HSA) were characterized by UV–Vis absorption, Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), fluorescence and circular dichroism spectroscopy, chemiluminescence and Neutral red assays. TEM analysis showed the formed faceted particles, large clumps/fused aggregates, nano-featured with the mean particle size of 41.60 nm. Chemiluminescence and Neutral red assays for in vitro antioxidant and cytotoxic activities of the SNPsArg/RF/HSA systems have been studied. It was pointed out that SNPsArg functionalized with RF and HSA resulted in a bio-nanosystem which leads to a high activity against oxygen free radicals, altered viability, morphology, apoptotic bodies and decreased cell density of L929 fibroblast cells. Results are relevant for understanding the redox properties of RF in the case of biological applications and especially for RF containing drugs. Graphical abstract Unlabelled Image Highlights • Synthesis of l ‑Arginine-Dextran70 based-silver nanoparticles (SNPs) (SNPsArg) • SNPsArg functionalized with Riboflavin (RF) and Human Serum Albumin (HSA) • In vitro antioxidant and cytotoxic activities of the SNPsArg/RF/HSA systems, were evaluated. • Results are relevant to the redox properties of RF in bio-nanosystems, especially for RF containing drugs. [ABSTRACT FROM AUTHOR]

Abstract A facile one step green synthesis of silver (AgNP), gold (AuNP) and platinum (PtNP) nanoparticles has been attempted using the rind extract of the fruit of Garcinia mangostana L. The rind of the fruit is enriched with wide varieties of natural resources which could be conveniently exploited as alternative for synthesis of nanoparticles eliminating the need for hazardous chemical methods. The formation of gold nanoparticles occurred at room temperature within a few seconds while the formation of silver and platinum nanoparticles was obtained after heating the solution for 20 min at 80 °C. Parameters such as contact time, temperature and pH were optimized to obtain the precise nanoparticles. The green synthesized nanoparticles were characterized using several state-of-the-art techniques like UV–Vis spectroscopic, FT-IR, HR-SEM and HR-TEM, XRD analyses and zeta potential measurements. Attempt has also been made to evaluate the antibacterial activity of the metal nanoparticles before and after combining with commercially used antibiotics as well as free antibiotics against human pathogenic bacteria. The bare silver nanoparticles (AgNP) showed relatively higher antibacterial activity than AuNP and PtNP and this activity was found to be more pronounced against gram negative bacteria than gram positive ones. Interestingly, all the three metal nanoparticles combined with antibiotics showed enhanced antibacterial activity against the pathogenic bacteria which suggested synergism between the nanoparticles and antibiotics. The high point of the present investigation has been that the Bacillus sp. which is highly resistant to streptomycin becomes highly susceptible to the same antibiotic when combined with gold nanoparticles. This particular observation opens up windows for the treatment of antibiotic resistant bacteria after combining with different nanoparticles under clinical set up. Highlights • The rinds of G. mangostana are discarded as wastes after fruit consumption can be effectively used for synthesizing nanoparticles. • The reduction potential of aqueous rind extract of G. mangostana was relatively higher with HAuCl 4 than AgNO 3 and H 2 PtCl 6. • The gold nanoparticles were stable for over 6 months at 4⁰C and this property can be exploited for fabrication of drugs. • Conjugation of antibiotics with nanoparticles has drastically enhanced the antibacterial activity when compared to bare nanoparticles. • Bacillus sp. which is inherently resistant to free streptomycin antibiotic, has become highly susceptible to nanoparticles conjugated with streptomycin. • These kinds of study can be extended to other drug resistant bacteria and with different antibiotic and nanoparticles combinations. [ABSTRACT FROM AUTHOR]

Abstract The biofilm accumulation over the composite resin restorations can contribute to the formation of secondary caries. In this way, antibacterial restorative composite resins are highly desired. Then, the purpose of this study was to modify a composite resins using Ag doped ZnO nanoparticles (NPs), evaluate the antibacterial and mechanical properties of the modified composite resin. The ZnO/AgNPs were synthesized by two different routes, polymeric precursor and coprecipitation methods, and characterized by thermal decomposition, X-ray diffraction, specific surface area by N 2 desorption/desorption and scanning electron microscopy (SEM). Antibacterial activity of composite resin specimens (4 mm in height and 2 mm in diameter; n = 15) modified by ZnO/Ag nanoparticles was performed against 7-days Streptococcus mutans biofilm. Colony forming units (CFU/mL) were used to evaluate the bacterial activity. Additionally, the morphology and the bacteria adherence area were analyzed by SEM images. Cylindrical specimens (6 mm in height and 4 mm in diameter; n = 20) of the composite resin containing ZnO/Ag NPs were prepared to perform compressive strength in a universal mechanical test machine, and the surface of fractured specimens was analyzed by EDX element mapping to verify NPs homogeneity. The normal distribution was confirmed and the two-way analysis of variance (ANOVA) and Tukey's test for pair comparison were performed. The nanospheres of ZnO/Ag lead to a better biofilm inhibition, than nanoplates. No difference on compressive strength was found for the composite resin modified by ZnO/Ag nanoplates. Based on these results, this material could be a good option as a new restorative material. Highlights • ZnO micro and nanoparticles with antimicrobial properties were satisfactorily synthetized by the different routes. • The composite resin containing ZnO particles significantly inhibit the S. mutans biofilm. • The compressive strength of the composite resin containing Ag/ZnO nanoplates did not drastically changed. [ABSTRACT FROM AUTHOR]

Abstract Not only are the physicochemical properties and biocompatibility of biomaterials important considerations, but also their antibacterial properties. In this study, a novel chemically-cross-linked antibacterial porcine acellular dermal matrix (pADM) scaffold was fabricated according to a two-step method. A naturally-derived oxidized chitosan oligosaccharide (OCOS) was used to cross-linked pADM (termed OCOS-pADM) to improve its physicochemical properties. Residual aldehyde groups within the OCOS-pADM were used in a redox reaction with Ag ions to produce Ag nanoparticles (AgNPs) in situ. As the AgNPs were tightly adhered onto the scaffold fibrils (termed OCOS-AgNPs-pADM), this effectively functionalized scaffold with antibacterial properties. The generated AgNPs were characterized by UV–Vis diffuse reflectance spectroscopy, XPS and SEM. The results of DSC, TG and enzymatic degradation demonstrated that OCOS-AgNPs-pADM possessed improved thermal stability and resistance to enzymatic degradation compared with pADM scaffolds. The kinetic experiment of the release of silver showed that silver was released in a controllable way. After introducing AgNPs into scaffolds, the OCOS-AgNPs-pADM possessed wide-spectrum antibacterial activity against Escherichia coli and Staphylococcus aureus. Furthermore, MTT assay and CLSM showed that the scaffolds had good biocompatibility. Pieces of OCOS-AgNPs-pADM were implanted into Sprague-Dawley rats to characterize their ability to repair full-thickness skin wounds. And results showed that the OCOS-AgNPs-pADM could accelerate the wound healing process. Overall, this work contributes new insight into the chemical cross-linking and functionalization of pADM scaffolds. In addition, as novel antibacterial scaffolds, OCOS-AgNPs-pADMs have the potential for development as wound dressing materials. Highlights • A naturally-derived oxidized Chitosan Oligosaccharide was used to cross-link porcine acellular dermal matrix (OCOS-pADM). • AgNPs were produced in-situ according to a green synthesis method using the residual aldehyde groups within OCOS-pADM. • A novel chemically-cross-linked antibacterial pADM scaffold (OCOS-AgNPs-pADM) was fabricated according to a two-step method. • The physicochemical properties and antibacterial property of OCOS-AgNPs-pADM were improved compared with native pADM. • The evaluation of in vitro biocompatibility indicated that OCOS-AgNPs-pADM had good biocompatibility. [ABSTRACT FROM AUTHOR]

Abstract Bioglass nanoparticles (BGs) are of outmost importance in the biomedical field, because their unique characteristics, namely osteoconductivity and osteoinductivity, and also in certain conditions, angiogenic and bactericidal properties. In this work, novel bioglass nanoparticles containing silver (AgBGs) were synthesized by a sol-gel method, adopting different thermal treatments to obtain new nanoparticles with bioactive and antibacterial features. This is the first systematic study of the effect of the thermal treatment on the properties of AgBGs. The effect of the studied thermal treatments on the properties of synthesized nanoparticles was analyzed by several characterization techniques: FT-IR, XRD, S-TEM, SEM-EDS and Zeta potential. FT-IR allowed the identification of the characteristic peaks of the nanoparticles and XRD revealed the presence of the characteristic peaks of an apatite-like phase. By S-TEM analysis it was found that the produced nanoparticles are dense and have a diameter <200 nm. The SEM micrographs showed their surface morphology and Zeta potential measurements were performed to study their suspension stability. Additionally, in vitro bioactivity tests confirmed their bioactive potential and the microbiological tests evidenced their bactericidal effect. These promising AgBGs could be incorporated either in 2D or 3D structures for several biomedical applications, namely in the orthopedic and dental fields. Graphical abstract Unlabelled Image Highlights • A new sol-gel procedure with distinct thermal treatments for the production of AgBGs is described and characterized. • Their Zeta potential values proved their stability and also their bioactive behavior. • SEM and S-TEM results evidenced nanosized particles and EDS analysis confirmed the incorporation of Ag on these AgBGs. • XRD patterns confirmed the apatite-like phase and FTIR spectra showed characteristic peaks of the siloxane bonds. • AgBGs revealed antibacterial effect within 16 h, suggesting their potential ability to inhibit bacterial infections. [ABSTRACT FROM AUTHOR]

Abstract Reactive oxygen species (ROS) cause oxidative stress, which involves in the pathogenesis of many serious diseases. Apoferittin containing gold-silver nanoparticles (Au-Ag-AFT) was designed and evaluated as a nanozyme for scavenging the ROS. The nanozyme consisting of silver-gold nanohybrid in apoferittin cage represents superoxide dismutase, catalase and peroxidase mimetic activities. The Au-Ag-AFT nanozyme was characterized by spectroscopy, FESEM, TEM and dynamic light scattering. The inhibition process for pyrogallol autoxidation was used for assaying the superoxide dismutase mimetic activity and measuring the kinetic parameters of Au-Ag-AFT nanozyme. Additionally, Aebi method and standard protocol was used for evaluating the catalase and peroxidase mimetic activity. The k cat values for superoxide dismutase, catalase and peroxidase mimetics activity were 1.4 × 106, 0.1 and 9 × 103 s−1 respectively. These values indicated that Au-Ag-AFT nanozyme could act as a suitable ROS scavenger. Additionally, Au-Ag-AFT nanozyme was examined as a protective agent for human sperm against oxidative stress induced during the cryopreservation process. Presence of the nanozyme in the sperm media significantly increased the motility and viability of the cells and also decreased the ROS, apoptosis and necrosis (P < 0.05) compare to the control group. Graphical abstract Unlabelled Image Highlights • Apoferittin containing gold-silver nanparticles (Au-Ag-AFT) was synthesized and introduced as a nanozyme. • Au-Ag-AFT exhibits superoxide dismutase, peroxidase and catalase mimetic activity. • The triple enzyme mimetic activity of Au-Ag-AFT is comparable with the activity of the above natural enzymes. • Au-Ag-AFT reduces oxidative stress of sperm cells during cryopreservation. [ABSTRACT FROM AUTHOR]

Abstract We report the synthesis and in vitro evaluation of dual-function chitosan-silver nanoparticles (CTS-AgNPs) films with potential applications as wound dressings. We attempted to formulate nanocomposite films with appropriate AgNPs concentrations to simultaneously display antibacterial activity and suitability for cell culture. Nanocomposites were obtained by CTS-mediated in situ chemical reduction of AgNO 3. Circular-shape AgNPs (sizes ca. 7–50 nm) well distributed within the CTS matrices were obtained in concentrations from 0.018 to 0.573 wt%. Efficacy (bacteriostatic and bactericidal properties) of CTS-AgNPs films to decrease planktonic and biofilm bacterial growth was AgNPs concentration- and bacteria strain-dependent. Films showed significant antibacterial activity against Gram-negative E. coli and P. aeruginosa and Gram-positive S. aureus. Antibacterial activity against S. epidermidis was moderated. Films suitability for cell culture was characterized using primary human fibroblasts (HF). HF displayed cell viability higher than 90% and the characteristic fusiform morphology of adhered fibroblast upon culture on films with AgNPs concentration ≤ 0.036 wt%. HF cultured on these films also showed positive expression of tropoelastin, procollagen type I and Ki-67, characteristic proteins of extracellular matrix and proliferative cells, respectively. In vitro assays demonstrated that cytocompatibility/antibacterial properties decreased/increased as silver concentration increased, suggesting that CTS-AgNPS nanocomposite films with ≈0.04–0.20 wt% might be considered as potential temporary dual-function wound dressings. Graphical abstract Unlabelled Image Highlights • Dual-functional CTS-AgNPs nanomaterials for wound dressing were obtained. • Preparation of CTS-AgNP produces spherical and stable NPs embedded with low toxicity. • CTS-AgNP demonstrates high antibacterial properties dependent of bacterial strain. • Viability and proliferation of human fibroblasts were demonstrated in CTS-AgNP films. [ABSTRACT FROM AUTHOR]

Abstract The mechanisms of reduction of silver ions and subsequently oxidation of silver atoms in the presence of polyoxometalates (POMs) are discussed. A step-by-step room temperature electron reduction of silver ions and its subsequent reactions has been used in this work to monitor oxidation of silver atoms and its clusters. The silver atoms can transfer electron to POMs is revealed by decrease in the yield of silver clusters and increase in their decay rates. The results of continuous γ-irradiation are compared using UV–visible (UV–Vis) absorption spectra, underlying the effect of silver atoms accumulation in the absence of POMs. Silver nanoparticles (Ag NPs) prepared by reduced silicotungstic acid (STA) were used as Raman substrate and also for antibacterial studies against panel of human pathogenic bacteria. The Ag NPs exhibited antibacterial activity against both Gram-positive and Gram-negative bacterial pathogens evaluated by well diffusion assay. The inhibition zones were within the range of 10 to 14 mm. We have also explored the surface enhanced Raman scattering (SERS) activity of the Ag NPs substrates using 1.0 × 10−7 M solution of crystal violet (CV) as Raman probe molecule. It was possible to detect SERS spectral pattern of CV on Ag NPs substrate with a high signal-to-noise ratio. Both SERS and antibacterial studies show that this simple, low cost, and greener method for synthesizing Ag NPs may be valuable in future studies about SERS sensor development and bio-applications. Graphical abstract Unlabelled Image Highlights • Oxidation of Ag clusters in the presence of POMs. • Decay rate of Ag atom increases in the presence of POMs. • Ag NPs stabilized by STA show good Raman activity. • Ag NPs stabilized by STA show good bactericidal property. [ABSTRACT FROM AUTHOR]

Abstract Extracts obtained from different plant species proved to be a valuable tool in various biomedical applications. In the same time, the phytosynthesis of noble metal nanoparticles represents an already well-established route for obtaining nanoparticles with biological activity. The present paper studies the antioxidant activity and the cytogenetic effects of the alcoholic extracts from rhizomes of Aconitum toxicum Rchb., before and after the phytosynthesis of gold and silver nanoparticles, on the meristematic root cells of Allium cepa L., and on the general mitotic index and the progression rate through the mitotic phases, respectively, as well as on the genetic material organized in chromosomes. The extracts were characterized in terms of total polyphenolics content (1.49% and, respectively, 2.29%) and aconitine content (by HPLC – 4.891 mg/L and, respectively, 18.211 mg/L), while the phytosynthesis of metallic nanoparticles was monitored by UV–Vis spectrometry, X-ray diffraction, X-ray fluorescence and electron microscopy. Both the extracts and the obtained nanoparticles were evaluated for antioxidant potential (the antioxidant activity ranging between 78% and 84.32%) and cytogenetic effects. The obtained results prove the phytosynthesis of AgNPs and AuNPs with dimensions ranging from 9 nm to 15 nm for AuNPs, respectively from 53 nm to 67 nm for AgNPs. The extracts obtained from rhizomes of A. toxicum Rchb. induced mitotic stress, as well as a series of nuclear and mitotic aberrations. The biosynthesis of AgNPs and AuNPs intensified the antioxidant and mitostimulatory activity of the extracts. Graphical abstract Unlabelled Image Highlights • Extracts of A. toxicum were used for metallic nanoparticles phytosysnthesis. • Extracts and nanoparticles were evaluated for antioxidant potential and cytogenetic effects. • Nanoparticles biosynthesis intensified the antioxidant and mitostimulatory activity of the extracts. [ABSTRACT FROM AUTHOR]

Abstract Silver nanoparticles (Ag NPs) serve numerous chief functions in cosmetics, engineering, textile, food technology and medicine. These nanoparticles are also utilized in the pharmaceutical industry particularly in the production of novel antimicrobial agents. However, despite the various studies of Ag NPs induced toxicity, there is a lack of information concerning cellular toxicity mechanisms of these nanoparticles on human cells. In the current project, we investigate the anti-cancer effects of Ag NPs in HepG2 (liver hepatocellular adenocarcinoma) cells. The mean particle size and morphology for the prepared nanoparticles were determined by dynamic light scattering (DLS) and transmission electron microscopy (TEM), respectively. Cell viability, reactive oxygen species (ROS) formation, cytochrome c amount and expression level of BAX/CASP 3/CASP 8/CASP 9 were assayed in HepG2 cells after incubation with Ag NPs. The prepared nanoparticles showed the mean particle size of 30.71 nm with polydispersity index (PDI) of 0.21. Our results revealed decreased cell viability in a concentration-dependent manner and the IC50 of 75 μg/mL for Ag NPs. Ag NPs cytotoxicity was associated with induction of ROS and cell apoptosis in HepG2 cell line. According to our findings, Ag NPs could be considered as potential chemotherapeutic agents in the treatment of liver hepatocellular carcinoma. Highlights • The proposed size of nanoparticle is about 30 nm. • Anti-cancer effects of Ag-NPs were tested with in vitro assays in HepG2 cells. • Hepatocellular carcinoma cell proliferation was inhibited via the induction of cytotoxicity and apoptosis. [ABSTRACT FROM AUTHOR]

Abstract Catalytic Reduction of p-nitrophenol and Methylene blue by Microbiologically Synthesized Silver Nanoparticles was studied in the present investigation. Catalytic reduction of 4-Nitophenol/p-nitrophenol (PNP) and methylene blue (MB) was assessed using both intra and extracellular silver nanoparticles (AgNP) with and without immobilization. Both intracellular and extracellular AgNP were synthesized from actinomycetes. Antimicrobial activity of AgNP was also assessed and it was found that, intracellular AgNP have significant antibacterial activity against E. coli , S. typhi and B. subtilis. Synthesized biogenic silver nanoparticles were characterized by UV–visible spectrophotometry, FTIR, XRD, and TEM-EDS. It was found that, extracellular AgNP are efficient as compared to intracellular AgNP in terms of PNP reduction. Graphical abstract Unlabelled Image Highlights • Extracellular silver nanoparticles have excellent catalytic activity in reduction of p-nitrophenol. • Immobilized intra and extracellular AgNPs have good methylene blue reduction ability. • The XRD pattern confirms the face centered cubic (fcc) structure of nano silver. • TEM images reveal the presence of multidispersive nanosilver with varying size 4.7 nm, 6.8 nm and 18.8 nm with mean particle size 10.1 nm and exhibiting roughly spherical morphology. [ABSTRACT FROM AUTHOR]

Abstract High demand for silver nanoparticles due to their extensive applications in different field has raised need of eco-friendly green synthesis with determined biomedical effects. This study proposes a novel rapid controlled alkaline based green synthesis of antibacterial silver nanoparticles from Calotropis gigantea for reduced cytotoxic effects. Silver nanoparticles termed as FAg, FAg1N, and FAg5N were synthesized with the help of floral extract of Calotropis gigantea as reducing and capping agent in presence of UV light and NaOH for catalysis and were characterized for their physiochemical properties by FESEM, DLS, UV–Visible spectrophotometry and FTIR. Facile synthesized Silver nanoparticles FAg1N and FAg5N showed enhanced antibacterial effects than FAg with increased NaOH concentration. Cytotoxic effect was found to be reduced at optimized alkaline conditioned FAg1N than FAg and FAg5N. Molecular dynamics study depicted the significant role of configurational change in “Calotropin” at variable alkalinity for controlling the size and physiological properties of synthesized AgNPs. The mechanism of cytotoxicity was revealed as consequences of variability in the interaction of Sod1 and P53 proteins with AgNPs surface for oxidative stress induction and programmed cell death. Highlights • Alkaline based size controlled biosynthesis of AgNP (FAg1N, 2N,5N and 10N) were done using Calotropis gigantea. • Biosynthesized FAg1N was most biocompatible compared to FAg2N, FAg5N and others. • Antibacterial activity of green synthesized AgNP increased with increase in NaOH concentration during synthesis. • Configurational changes in “Calotropin” in alkaline condition controls size of AgNP synthesis. • AgNP exhibit cytotoxicity by molecular interaction with Sod1 and P53 leading to altered oxidative stress and apoptosis. [ABSTRACT FROM AUTHOR]

Abstract The skin wounds cause serious burden to healthcare systems. The lack of sterility of the innate barrier function of the skin facilitates the development of microbial communities within the wound environment especially in biofilm form. Since biofilm is difficult to eradicate, new treatments have been established, such as silver nanoparticles (AgNPs), which antimicrobial and anti-biofilm properties have been studied, nevertheless, their toxic effects are known too. Different concentrations of AgNPs stabilized with a biocompatible and thermo-reversible vehicle as hydrogel Pluronic F-127 were synthesized, those formulations presented interesting thermo-reversibility which could be used to apply on wounds. The formulations (Gel 62.5, 125, and 250 ppm of AgNPs) proposed in this study showed in vitro a total inhibition of clinical strains ( Staphylococcus aureus and Pseudomonas aeruginosa ) in planktonic form, as well as, anti-biofilm activity was archived with the formulation of Gel 250 ppm, a total inhibition of biofilm formation with mixed culture was registered in the first 30 min of biofilm growth; even more, the viability of human fibroblasts with all gels formulations was >95%, in contrast to silver sulfadiazine cream 1% which showed the highest cytotoxic effect. PF-127 gel with AgNPs could be a prophylactic treatment for skin wounds, because its activity in critical steps on biofilm formation. Highlights • The formulations of the hydrogels designed showed engaging features with potential like prophylactic treatment • PF-127 – AgNPs gel had significant antibacterial effect against planktonic form and anti-biofilm activity in critical steps • PF-127 – AgNPs gel was less toxic to human fibroblasts than Silver sulfadiazine cream 1 % • PF-127 – AgNPs gel has outstanding features: thermo-reversibility, antimicrobial activities and cytotoxicity to wound healing [ABSTRACT FROM AUTHOR]

Abstract The present study deals with sequential optimization strategy based on Box-Behnken method to optimize the process variables for efficient production of Ocimum sanctum synthesized silver nanoparticles using biological synthesis. Four substantial factors influencing the dependent variables viz size, zeta potential, Polydispersity index (PDI) and yield were identified as silver nitrate concentration, temperature, amount of plant extract and stirring speed as independent variables. The contribution of the studied factors in monitoring dependent variables was evaluated via analysis of variance. The validity of the model developed was verified, and the statistical analysis showed that the optimal operational conditions were AgNO 3 concentration 5.29 mM, temperature 60 °C, agitation speed of 500 rpm and plant extract 2.24% (w/v) which primes to form silver nanoparticles of smallest size 83.41 nm and 0.24 with maximum zeta potential of -20.20mV and Yield of 18.62. In addition, the optimized AgNPs were characterized using DLS, TEM, FE-SEM and UV‐vis analysis. The topical formulation was prepared by incorporation of optimized AgNPs into the carbopol gel base. Further, the gel was evaluated in vivo using the rat model of skin wound healing. The measurement of the wound areas was performed on 2nd, 4th, 6th, 8th, 10th, 12th and 14th days and the percentage of wound closures were calculated accordingly. By the 14th day, silver nanoparticle gel showed 96.20% wound healing activity compared with that of the standard as well as control base. The antibacterial inhibitory efficiency of prepared nano gel was found similar to the commercial product against the Staphylococcus aureus , E. coli and Pseudomonas aeruginosa. Graphical abstract Unlabelled Image Highlights • Efficient method to synthesize AgNPs using aqueous O. sanctum leaf extract that acted both as reducing and capping agent. • Box-Behnken method to optimize the process parameters for silver nanoparticles production. • Development of topical dosage gel and evaluated in vivo using the burn wound healing model on wistar albino rats. [ABSTRACT FROM AUTHOR]

Abstract Herbs having various natural substances can be utilized for the biosynthesis of Silver nanoparticles (AgNPs) and act as a stable, reliable and biocompatible alternative instead of the current physical and chemical approaches. It has been reported that Matricaria chamomilla possesses unique properties, especially anti-cancerous effects. The objective of the current work was to assess the chemical characteristics and anticancer effects of biosynthesized AgNPs applying aqueous extracts of M. chamomilla against A549 lung cancer cells. UV–visible spectrum showed the maximum absorption of the biosynthesized AgNPs at 430 nm. The crystalline structure of biosynthesized AgNPs in optimal conditions was confirmed by XRD. Moreover, the presence of Ag as the ingredient element was exhibited via EDX analysis. FT-IR results also verified the AgNPs synthesis using a plant extract. The spherical shapes of the AgNPs with an average diameter size around 45.12 nm and a zeta potential value of −34 mV were characterized using DLS, and confirmed through FE-SEM and TEM. In vitro cytotoxicity assay using MTT revealed that the biosynthesized AgNPs exhibited a dose- and time- dependent cytotoxic effect against A549 lung cancer cells. Moreover, the apoptotic effects of the AgNPs were demonstrated using DAPI staining, real-time PCR and flow cytometry. According to these findings, using M. chamomilla in combination with AgNPs via green-synthesis approach may be an efficient strategy for effective treatment of lung cancer. Highlights • Matricaria chamomilla extract was used as capping agent to synthesize AgNPs without production of any harmful chemicals. • The biosynthesized AgNPs with uniformity and good stability exhibited remarkable anti-cancer effects against A549 cells. • Using M. chamomilla in combination with AgNPs may be an efficient strategy for effective treatment of lung cancer. [ABSTRACT FROM AUTHOR]