Biocompatible Silver Nanoparticles Research Articles

Uncaria gambir Roxb. mediated green synthesis of silver nanoparticles using diethanolamine as capping agent

Studies of silver nanoparticles preparation has been developed increasingly due to the wide application in various areas and field, such as medicine, energy, catalysis, and electronic. An environmental-friendly method is needed to fabricate biocompatible silver nanoparticles without producing hazardous materials to the environment. In this study, we synthesized silver nanoparticles by green synthesis method, using leaf extract of gambir (Uncaria gambir Roxb.) as bioreducing agent and aqueous diethanolamine (DEA) solution as capping agents. The AgNO3/DEA molar ratio was varied to investigate the effect of DEA concentration to the properties of silver nanoparticles. The formation of silver nanoparticles was indicated by colour changes to yellowish brown and confirmed by result of UV-Vis spectrophotometer analysis which shown absorption band at 400 to 410 nm. The absorbance was increased to the reaction time of 24 hours, and was decrease by the increasing of DEA concentration in reaction. TEM analysis showed that prepared silver nanoparticles were spherical in shape with diameter of 3,5 - 45,5 nm. The diameter of DEA capped silver nanoparticles was 13 nm, smaller than uncapped silver nanoparticles which was 26 nm It exhibited good stability to time reaction of one month which was potential to be developed in some fields.

Designing Ecofriendly Bionanocomposite Assembly with Improved Antimicrobial and Potent on-site Zika Virus Vector Larvicidal Activities with its Mode of Action

Dialyzed natural polymer, fibroin, from Bombyx mori was used to synthesize biocompatible silver and gold nanoparticles in-situ in dispersion form. The films of pure fibroin (PF), fibroin-silver nanocomposite (FSNC) and fibroin-gold nanocomposite (FGNC) were fabricated by drop casting method. The characterization of the resultant dispersion and films was performed by visual color change, UV-Vis spectroscopy and atomic force microscopy. The dispersions of PF, FSNC and FGNC were tested for antibacterial activity against E. coli NCIM 2065, S. aureus NCIM 5021, K. pneumoniae NCIM 2957, P. aeruginosa ATCC 9027 and antifungal activity against A. fumigatus NCIM 902. FSNC dispersion exhibited an effective antimicrobial action against all the tested microbes as compared to FGNC dispersion. The mechanism of action for FSNC and FGNC against these microorganisms is proposed. Additionally, the larvicidal activity of the films was investigated against the larvae of Aedes aegypti. The films of FSNC exhibited 100% mortality while the films of FGNC revealed 86–98% mortality against all the larval instars and pupae of A. aegypti. The phytotoxicity study of the nanocomposite films was also carried out to confirm the reusability of water. This is first noble metal nanocomposite based report on larvicidal activity of zika virus vector.

Characterisation of silver nanoparticles synthesised by Bacillus thuringiensis as a nanobiopesticide for insect pest control

ABSTRACTNanotechnology has become one of the most promising new approaches for pest control in recent years. In this research, biocompatible silver nanoparticles (Btk-AgNPs) were synthesised by using the entomopathogenic bacterium, Bacillus thuringiensis kurstaki (Btk) as a low-cost and eco-friendly production system. The AgNP samples exhibited a brownish-yellow colour that is characteristic for silver nanoparticles synthesis. Btk-synthesised AgNPs were produced using both the supernatant and pellet of Bt culture at various concentrations and AgNP particles were characterised by UV-Vis spectrophotometer and Dynamic Light Scattering (DLS). The variation of hydrodynamic diameter (Dh) and UV-Vis spectra of silver particles produced by various concentration of culture showed that production of AgNPs was maximised when using 20% for either supernatant or pellet treatments of Bt of culture and the size of particles was around 85 nm for both. The insecticidal efficacy of Btk-synthesised AgNPs against larvae of the cabbage looper, Trichoplusia ni (Hübner) and black cutworm, Agrotis ipsilon (Hufnagel) was tested. Results demonstrated that the treatments of either Btk-synthesised AgNP(s) made with Bt supernatant or Btk-synthesised AgNP(p) using Bt pellet were found to be significantly more virulent toward larvae of T. ni than to A. ipsilon.

Nanopriming technology for enhancing germination and starch metabolism of aged rice seeds using phytosynthesized silver nanoparticles

Application of nanomaterials for agriculture is relatively new as compared to their use in biomedical and industrial sectors. In order to promote sustainable nanoagriculture, biocompatible silver nanoparticles (AgNPs) have been synthesized through green route using kaffir lime leaf extract for use as nanopriming agent for enhancing seed germination of rice aged seeds. Results of various characterization techniques showed the successful formation of AgNPs which were capped with phytochemicals present in the plant extract. Rice aged seeds primed with phytosynthesized AgNPs at 5 and 10 ppm significantly improved germination performance and seedling vigor compared to unprimed control, AgNO3 priming, and conventional hydropriming. Nanopriming could enhance α-amylase activity, resulting in higher soluble sugar content for supporting seedlings growth. Furthermore, nanopriming stimulated the up-regulation of aquaporin genes in germinating seeds. Meanwhile, more ROS production was observed in germinating seeds of nanopriming treatment compared to unprimed control and other priming treatments, suggesting that both ROS and aquaporins play important roles in enhancing seed germination. Different mechanisms underlying nanopriming-induced seed germination were proposed, including creation of nanopores for enhanced water uptake, rebooting ROS/antioxidant systems in seeds, generation of hydroxyl radicals for cell wall loosening, and nanocatalyst for fastening starch hydrolysis.

Nanosecond Laser-Assisted Fabrication of Colloidal Gold and Silver Nanoparticles and Their Conjugation with S-Ovalbumin

In the present work, we have investigated the functionalization of protein S-ovalbumin with laser-generated gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) using spectroscopic techniques. Biocompatible gold and silver nanoparticles were fabricated by nanosecond pulsed laser ablation (PLA) of metal target in water and directly conjugated to protein S-ovalbumin. The localized surface plasmon resonance (LSPR) of gold and silver nanoparticles is sensitive to particle size, shape, and surrounding medium refractive index. UV–visible absorption spectrum of both AuNPs and AgNPs showed red shift in LSPR after protein addition. The effect of laser fluence on the size of AuNPs and nanoparticle-protein conjugation in the size range 6–32 nm has been systematically studied. The presence of NPs resulted in broadening of S-ovalbumin absorption peak around 278 nm. Raman spectra of S-ovalbumin-NP assembly demonstrated breaking of disulfide bond and appearance of peak around 290 and 206 cm−1 corresponding to Au–S and Ag–S bond formation, respectively. Further, increase in the ratio of the 1350/1320-cm−1 doublet was observed, which indicates that hydrophobicity for tryptophan residues in the protein-NP assembly has increased. Fluorescence spectroscopy showed quenching in emission intensity of S-ovalbumin in the presence of AuNPs and AgNPs. The number of binding sites between AuNPs and S-ovalbumin has been found to be 1.4 with binding constant 4.5 × 109 M−1. The calculated values of binding constant and number of binding sites for AgNPs and S-ovalbumin were 2.4 × 109 M−1and 0.96, respectively.

A green route to synthesis silver nanoparticles using Sargassum polycystum and its antioxidant and cytotoxic effects: An in vitro analysis

The aim of the present study is to find out a biocompatible silver nanoparticles synthesized from Sargassum polycystum for antioxidant and anticancer activity. The phytochemical constituent was investigated by standard method and it possesses alkaloids, flavanoids, steroids, terpenoids, protein, amino acids, carbohydrate, quinones, phenols and tannins. The synthesized AgNPs were characterized by various spectroscopic and microscopic techniques. Interestingly, AgNPs exhibit highest level of DPPH radical scavenging (78.2% of inhibition), reducing power (0.18±0.006) and total antioxidant activities (59.2±0.54%) when compared to crude extract. IC50 value of AgNPs was 20µg/ml against human colon cancer (HT-29) cells through in vitro cytotoxicity assay and the activity was proportionate to the concentration of AgNPs. Thus the present finding confirms that the synthesized AgNPs possess antioxidant and anticancer properties.

Environment friendly approach for size controllable synthesis of biocompatible Silver nanoparticles using diastase.

A green, facile method for the size selective synthesis of silver nanoparticles (AgNPs) using diastase as green reducing and stabilizing agent is reported. The thiol groups present in the diastase are mainly responsible for the rapid reaction rate of silver nanoparticles synthesis. The variation in the size and morphology of AgNPs were studied by changing the pH of diastase. The prepared silver nanoparticles were characterized by using UV-vis, XRD, FTIR, TEM and SAED. The FTIR analysis revealed the stabilization of diastase molecules on the surface of AgNPs. Additionally, in-vitro cytotoxicity experiments concluded that the cytotoxicity of the as-synthesized AgNPs towards mouse fibroblast (3T3) cell lines is dose and size dependent. Furthermore, the present method is an alternative to the traditional chemical methods of size controlled AgNPs synthesis.

Biocompatible silver nanoparticles prepared with amino acids and a green method.

The synthesis of nanoparticles is usually carried out by chemical reduction, which is effective but uses many toxic substances, making the process potentially harmful to the environment. Hence, as part of the search for environmentally friendly or green synthetic methods, this study aimed to produce silver nanoparticles (AgNPs) using only AgNO3, Milli-Q water, white light from a xenon lamp (Xe) and amino acids. Nanoparticles were synthetized using 21 amino acids, and the shapes and sizes of the resultant nanoparticles were evaluated. The products were characterized by UV-Vis, zeta potential measurements and transmission electron microscopy. The synthesis of silver nanoparticles with tryptophan and tyrosine, methionine, cystine and histidine was possible through photoreduction method. Spherical nanoparticles were produced, with sizes ranging from 15 to 30nm. Tryptophan does not require illumination nor heating, and the solution color changes immediately after the mixing of reagents if sodium hydroxide is added to the solution (pH=10). The Xe illumination acts as sodium hydroxide in the nanoparticles synthesis, releases H+ and allows the reduction of silver ions (Ag+) in metallic silver (Ag0).

Green synthesis, characterisation and biological evaluation of AgNPs using Agave americana, Mentha spicata and Mangifera indica aqueous leaves extract.

The current study was performed to synthesize stable, eco-friendly and bio-compatible silver nano-particles (AgNPs) of Agave americana, Mentha spicata and Mangifera indica leaves and to screen them for biological activities. The ultraviolet-visible spectroscopic analysis revealed that λ-max for AgNPs range from 350-500 nm. All AgNPs possessed polycrystalline structure as notified as intense graphical peaks in complete spectrum of 20 values ranging from 10-80° in X-ray diffraction measurements and supported by scanning electron microscopy data. The size of the nano-particles was confirmed by transmission electron microscopy (30-150 nm). Mass loss at variable temperatures was evaluated by simultaneous thermogravimetric and differential thermal analysis revealed reduction in mass and activity of compounds was notified by temperature increase from 200 to 800 °C, thus concluding it as thermally sensitive compounds. A. americana AgNPs showed significant (96%) activity against Methicillin resistant Staphylococcus aureus, Escherichia coli (95%) and Fusarium oxysporum (89%). Good antioxidant activity was shown by M. spicata AgNPs at 300 µl (79%). M. indica AgNPs showed significant phytotoxic activity (88%) at highest concentration. No haemagglutination reaction was observed for the test samples. The above results revealed that AgNPs synthesized from selected plant species possesses significant antimicrobial and phytotoxic effect.

Biocompatible silver nanoparticles reduced from Anethum graveolens leaf extract augments the antileishmanial efficacy of miltefosine

Despite the existence of chemotherapy, there is no effective cure for leishmaniasis. In the light of recommended therapeutic regimen is attributed for toxicity and development of clinical resistance, exploration of an efficient method of drug delivery could be one of the option in reducing the dosage and toxicity of drugs. This work is aimed in such fashion to study the enhanced antileishmanial activity of miltefosine with silver-nanoparticles (AgNPs) synthesized by using Anethum graveolens (dill) leaf extract as reducing agent. AgNPs were synthesized in a single step process and characterized by UV-visible, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR) to understand the crystal structure and functional groups on their surface. TEM analysis showed that the synthesized AgNPs are of an average size of 35 nm. By performing MTT assay, we found that, AgNPs (between 20 and 100 μM) are biocompatible in nature through pertaining >80% viability of macrophages. Furthermore, AgNPs alone (50 μM) have not shown antileishmanial effect on promastigote stage of Leishmania parasite but in combination with miltefosine (12.5 μM and 25 μM), it magnifies the leishmanicidal effect of miltefosine by ∼2-folds (i.e. AgNPs cut down the IC50 of miltefosine about to half). Scanning electron microscopic (SEM) observation for morphological aberration and genomic DNA fragmentation in promastigotes confirmed the enhanced effect of meltefosine in combination with AgNPs (50 μM AgNPs plus 12.5 μM miltefosine). Similarly, this combination has likely shown a slight augmentation (p = 0.057) of miltefosine (2.5 μM) leishmanicidal efficacy on amastigote stage of the parasite in infected human macrophages by reducing their intracellular growth.

Green synthesis of biocompatible silver nanoparticles mediated by Osmanthus fragrans extract in aqueous solution

A practical, convenient and green method for the synthesis of highly stable and small sized silver nanoparticles with narrow distribution from 2nm to 30nm is reported. Silver nitrate was used as silver precursor, and Osmanthus fragrans extract was acted as capping agent as well as reducing agent. The formation of silver nanoparticles was observed by the change of color from colorless to yellow. The as-prepared silver nanoparticles were characterized by scanning electron microscope (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopic (HRTEM), UV–vis spectroscopy (UV-vis), X-ray diffraction (XRD) and Fourier transform infra-red spectroscopic (FT-IR). The formation of silver nanoparticles was confirmed by its characteristic surface plasmon absorption peak at 400–450nm in UV–vis spectra. The TEM and SEM images showed that the as-synthesized silver fine spherical particles are distributed uniformly with a narrow distribution from 2nm to 30nm. The HRTEM and XRD results demonstrated that the obtained metallic nanoparticles were single crystalline silver nanoparticles. FT-IR data revealed that the silver nanoparticles are coated with Osmanthus fragrans extract. The effects of the silver nitrate and Osmanthus fragrans extract concentrations on the particle size were investigated. The green synthesis method is simple and may be extended to preparation of other noble metal nanoparticles.

Phytogenic synthesis of silver nanoparticles, optimization and evaluation of in vitro antifungal activity against human and plant pathogens

An attempt was made to synthesis of biocompatible silver nanoparticles from ten different Cassia spp. Among them, Cassia roxburghii aqueous leaf extract supported the synthesis of highly efficient and stable AgNPs. The synthesis of AgNPs was optimized at different physico-chemical condition and highly stable AgNPs were synthesized with 1.0mL of C. roxburghii leaf extract, pH 7.0, 1.0mM AgNO3 and at 37°C. The synthesized AgNPs were characterized by XPS, DLS and ZETA potential. DLS and ZETA potential analysis, the average AgNPs size was 35nm and the zeta potential was −18.3mV. The AgNPs exhibit higher antifungal activity when compared with the conventional antifungal drug amphotericin B against all the tested human fungal pathogens such as Aspergillus niger, Aspergillus fumigatus, Aspergillus flavus, Penicillium sp., Candida albicans and the plant pathogens such as Rhizoctonia solani, Fusarium oxysporum and Curvularia sp. Scanning electron microscope (SEM) analysis showed distinct structural changes in the cell membranes of C. albicans upon AgNPs treatment. These results suggest that phytosynthesized AgNPs could be used as effective growth inhibitors in controlling various human and plant diseases caused by fungi.

Biocompatible silver nanoparticles embedded in a PEG–PLA polymeric matrix for stimulated laser light drug release

The laser-induced release of a well-known hepatoprotective drug (silibinin, SLB) from a temperature-sensitive polymeric composite loaded with silver nanoparticles (Ag NPs) was investigated. The surface chemistry tuning and the specific design of Ag NPs are fundamental in view of the engineering of specific stimuli-responsive systems, able to control drug release in response to external stimuli. The release profiles of SLB from the newly synthesized PEG–PLA@Ag composite show strong dependences on laser wavelength and Ag NPs’ Surface Plasmon Resonance (SPR). The resonant laser light excites the SPR of the NPs and the absorbed energy is converted into heat due to electron–photon collisions. The heat generated from the nanometer-sized metal particles embedded within the polymer is efficient and strongly localized. The nanovector, irradiated by a relatively low-intensity laser but tuned specifically to the metal NPs’ SPR, releases the encapsulated drug with a higher efficiency than that not irradiated or irradiated with a laser wavelength far from the metal SPR. A combination of analytical techniques including UV–Vis, NMR, and FT-IR spectroscopy and scanning/transmission electron microscopy has been used to study the structural and morphological properties of the composite. The controllable specificity of this approach and the possibility of the SPR-mediated localized photothermal effect to be usefully applied in aqueous environments are the relevant advances of the proposed system for photothermal therapies that make use of visible optical radiation or for the drug delivery in proximity of the tumor cells.

New challenges in the application of biocompatible silver nanoparticles in enology: Antimicrobial capacity, digestibility and potential cytotoxicity

In the search for new substitutes to the use of sulfur dioxide (SO2 ) in oenology, a new line of research based on nanotechnology has been launched. Within this line, this paper evaluates the suitability of two new biocompatible silver nanoparticles (Ag-NPs) to control microbial growth in wine as well as their stability and potential risks at intestinal level. Antimicrobial activities against spoilage wine microorganisms were carried out in both culture media and wines. In addition, in vitro simulations (static and dynamic) were conducted to monitor the passage of Ag-NPs through the buco-gastrointestinal tract and also to assess their effects on the gut microbiota and intestinal epithelial cells. Both Ag-NPs proved to be highly efficient for the control of wine undesirable bacteria in culture media and microvinification assays, and to a lesser extent, for reducing Brettanomyces populations in wine. Furthermore, undigested Ag-NPs as their corresponding digests after gastrointestinal simulation were not toxic to intestinal microbiota either epithelial cells, at least at the conditions used in these experiments.

Inhibition of fibrillation of human serum albumin through interaction with chitosan-based biocompatible silver nanoparticles

Electrostatic interaction of chitosan-based silver nanoparticles with human serum albumin leads to inhibition of fibrillogenesis.

Antibacterial and anticancerous biocompatible silver nanoparticles synthesised from the cold-tolerant strain of Spirulina platensis

The new age drugs are nanoparticles of polymers, metals or ceramics are now extensively utilized in modern medicine and healthcare which can combat conditions like cancer and fight human pathogens. Nanomaterials based on biological origin is highly appreciable because of less toxicity, high efficacy and biocompatibility. In the present study, silver nanoparticles were synthesized from the biomass of cold tolerant strain of Spirulina platensis and the synthesized nanoparticles were evaluated against antibacterial and anti cancer activity. Silver nanoparticles were synthesized by the algal culture and characterized by UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM) and X ray diffraction (XRD) studies. Anti bacterial activity has been studied with free nanoparticles adopting agar diffusion assay, biofilm inhibition assay and nanoparticles fabricated wound dressing against representative gram negative organism Pseudomonas aeruginosa and gram positive organism Staphylococcus aureus respectively. The in vitro anti cancer activity of silver nanoparticles were screened against human Hep 2 cell lines by means of MTT assay. Reduction of silver ions by the algal culture was observed during 72 hours of incubation and the synthesized nanoparticles were further characterized. Anti bacterial study reveals both the strains were susceptible to free nanoparticles and fabricated wound dressing treatment. The in vitro anti cancer activity of silver nanoparticles were screened against human Hep 2 cell lines by means of MTT assay which reveals that cell viability has been reduced as dose dependent manner. The observed results imply that silver nanoparticles synthesized from Spirulina platens is cold tolerant strain can be used as potential anti bacterial and anti cancerous agent.

Novel biocompatible silver nanoparticles for controlling the growth of lactic acid bacteria and acetic acid bacteria in wines

This paper reports the inhibitory potential of two new silver-based biocompatible nanoparticles (Ag NPs), specifically synthesized for this study, against Gram-negative and Gram-positive bacteria, such as Escherichia coli and Staphylococcus aureus, and different wine lactic acid bacteria (LAB) (Oenococcus oeni, Lactobacillus casei, Lactobacillus plantarum and Pediococcus pentosaceus) and acetic acid bacteria (AAB) (Acetobacter aceti and Gluconobacter oxydans). Both solid nanoparticles, dried PEG-Ag NPs 1 (20.01% silver content) and glutathione-stabilized GSH-Ag NPs 2 solution (0.197 mg/mL silver content), showed homogeneous size distribution and physicochemical properties compatible with their use as antimicrobial agents. The nanoparticles showed different antimicrobial spectra, with PEG-Ag NPs 1 being more effective (lower IC50 values) against Gram-negative strains, whereas GSH-Ag NPs 2 showed similar efficiency against Gram-negative and Gram-positive strains, with the exception of O. oeni strains, which turned out to be notably susceptible to them (IC50 ∼1 μg/mL, Ag concentration). For the LAB and AAB tested, these nanoparticles showed IC50 values (particle concentration) of the same order as those for the widely used additive potassium metabisulphite, at least as calculated for PEG-Ag NPs 1. These results confirm the potential of Ag NPs in controlling microbial processes in winemaking, and open new investigations on the design and use of antimicrobial-specific silver-based nanoparticles in oenology.

Rapid synthesis of biocompatible silver nanoparticles using aqueous extract of Rosa damascena petals and evaluation of their anticancer activity

ObjectiveTo optimize the process parameters involved in the green synthesis of silver nanoparticles (G-SNPs) by aqueous extract of Rosa damascena petals and to evaluate the biocompatibility and anti cancer activity of the synthesized silver nanoparticles against human lung adenocarcinoma (A549). MethodsThe process variables that include concentration of extract, mixing ratio of reactants, silver salt concentration and interaction time were analyzed. The compatibility of the G-SNPs was verified by incubating with erythrocytes and the anticancer property of the G-SNPs against A549 cells was performed by MTT assay. ResultsFormation of G-SNPs was confirmed by the visual change in the colour of the reaction mixture from pale yellow to brown yellow. Surface plasmon resonance of synthesized G-SNPs was observed at 420 nm; the size of G-SNPs were analyzed by DLS and found to be in the range of (84.00±10.08) nm. Field emission scanning electron microscope and high resolution transmission electron microscopy analysis confirmed that the G-SNPs were fairly spherical. Fourier transform infrared spectroscopy spectroscopy and X-ray diffraction revealed the characteristic peaks of G-SNPs. Energy dispersive X-ray analysis showed a signal of silver around 3 keV. The synthesized G-SNPs exhibited anticancer activity as evidenced by the MTT assay. IC50 value of G-SNPs was found to be 80 μg/mL. ConclusionThe results of the present study suggest that G-SNPs can be synthesized rapidly within first minute of the reaction; they are biocompatible and possess anticancer activity against human lung adenocarcinoma.

Green silver nanoparticles: enhanced antimicrobial and antibiofilm activity with effects on DNA replication and cell cytotoxicity

Synthesis of green and biocompatible silver nanoparticles with high anti-microbial and anti-biofilm activities.

One-step green synthesis and characterization of leaf extract-mediated biocompatible silver and gold nanoparticles from Memecylon umbellatum.

In this experiment, green-synthesized silver and gold nanoparticles were produced rapidly by treating silver and gold ions with an extract of Memecylon umbellatum leaf. The reaction process was simple and easy to handle, and was monitored using ultraviolet-visible spectroscopy. The effect of the phytochemicals present in M. umbellatum, including saponins, phenolic compounds, phytosterols, and quinones, on formation of stable silver and gold nanoparticles was investigated by Fourier-transform infrared spectroscopy. The morphology and crystalline phase of the nanoparticles were determined by transmission electron microscopy and energy-dispersive x-ray spectroscopy. The results indicate that the saponins, phytosterols, and phenolic compounds present in the plant extract play a major role in formation of silver and gold nanoparticles in their respective ions in solution. The characteristics of the nanoparticles formed suggest application of silver and gold nanoparticles as chemical sensors in the future. Given the simple and eco-friendly approach for synthesis, these nanoparticles could easily be commercialized for large-scale production.