New biomaterials based on nanoparticles (NPs) carrying polyphenols-rich extracts (Cornus mas) recently showed promising anti-inflammatory activity in psoriasis. We aimed to understand how topically delivered silver and gold nanoparticles complexed with Cornus mas (Ag-NPs-CM, Au-NPs-CM) modulate inflammation in psoriasis at cellular and molecular level. The impact on psoriatic inflammation was assessed in vitro on pro-inflammatory macrophages, by clinical score, high-frequency ultrasonography and immunohistology of psoriasis plaques treated with Ag-NPs-CM, Au-NPs-CM or control. Incubation of pro-inflammatory macrophages with nanoparticles significantly decreased the release of NO, IL-12 and TNF-. Immunofluorescence confirmed that nanoparticles significantly reduced CD68-positive macrophages and their IL-12 and TNF- production in human psoriasis plaques. NPs-CM appear to repress NF-B activation in macrophages, inhibiting the production of pro-inflammatory factors with causal role in psoriasis. Ag and Au NPs-CM represent a novel nanoparticle-based green technology which may provide an efficient tool for modern psoriasis therapy, circumventing immunosuppression-related side effects of biologicals.

Natural extracts from European Cornel fruits have been found to be a significant source of natural antioxidants with health benefits for human body. In the present work we focused on using these extracts for preparing new nanomaterials based on metallic nanoparticles, taking in consideration that these metals have been used for a long time as treatment in medical fields. We have developed a synthesis method which permits to obtain the noble metal nanoparticles having anthocyanins from natural extract as ligands. We have characterized them by UV-Vis spectroscopy, Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC). Equilibrium constants of reactions between gold/silver nanoparticles and organic molecules as ligands have been determined in two ways and have been found of 104 orders of magnitude, values that suggest a good association between them. Some new medical products (creams) based on gold/silver-natural extracts have been applied on skin lesions appeared due to the psoriatic illness. The creams prepared have been used on a lot of 31 human subjects with skin lesions and after two months of treatment, a good anti-inflammatory effect has been observed. The good medical results have been confirmed by statistical studies

A green, rapid and cost effective method for the bio-synthesis of silver nanoparticles (AgNPs), using polyphenols present in European cranberry bush fruit extracts was developed. The obtained AgNPs were characterized by ultra-violet visible spectroscopy (UV–VIS), Fourier transform – infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and X-ray diffraction patterns (XRD). The average size of the spherical AgNPs was found to be 25 nm. The anti-inflammatory effect of the biomaterials was investigated, both in vitro (on HaCaT cell line, exposed to UVB radiation) and in vivo (on acute inflammation model in Wistar rats). Our results support the conclusion that the photosynthesized silver nanoparticles present a potent anti-inflammatory activity and could be successfully used as therapeutic tools for treatment of inflammation.

Among metallic nanoparticles gold possess several unique properties. It has been argued that AuNPs have significant toxicity both in vitro and in vivo but that coating may partially prevent harmful effects. Chitosan is a natural polysaccharide derivative of chitin known to have immunoenhancing effects, antitumor, antifungal and antimicrobial activities. The aim of this study was to investigate the cytotoxic effect of chitosan-AuNPs on C26 (murine colon carcinoma) and HeLa (human cervix carcinoma) cell lines. C26 and HeLa cells were exposed to 10 and 60 nm sized chitosan-AuNPs at five different concentrations (5, 10, 25, 50 and 100 μg/ml). After 24 h of incubation, cytotoxicity was assessed by the MTT colorimetric method and IC50 values were calculated. In C26 cells 60 nm particles were more toxic than 10 nm particles. On the other hand in HeLa cells the situation was reversed and 10 nm particles had the most harmful effect at a concentration 2.5 times smaller than that of 60 nm particles. Our results could suggest that chitosan-AuNPs have an antiproliferative effect on C26 and HeLa cell lines but that this depends on cell type and is influenced by particle size and concentration.

1 National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street RO 400293, Cluj-Napoca, Romania 2 Histology Department, Iuliu Hatieganu University of Medicine and Pharmacy, 13 Emil Isaac Street, 400023 Cluj-Napoca, Romania 3 Dermatology Clinic, Iuliu Hatieganu University of Medicine and Pharmacy, 13 Emil Isaac Street, 400023 Cluj-Napoca, Romania 4 Faculty of Mathematics and Informatics, Babes-Bolyai University, 1 Kogalniceanu Street, 400023 Cluj-Napoca, Romania

Gold nanoparticles (GNPs) were obtained by green synthesis with an extract from Cornus mas fruits (GNPs-CM), characterized by several methods, and their biologic effects were evaluated on two cell lines: HaCaT, normal keratinocytes, and A431, epidermoid carcinoma. GNPs were spherical with sizes between 2 and 24 nm. Their optical spectra had a dominant plasmonic band centered at 525 nm; zeta potential distribution was narrow, centered at −19.7 mV, and the mean hydrodynamic diameter was 58 nm. GNPs were visualized in both cell types entering the cells by endocytosis. The amount of gold uptaken by the cells was dose and time dependent. The intracellular concentration of Au ions was higher in HaCaT compared to A431 cells. The toxicity of GNPs-CM was dose dependent being significant only when the highest concentrations were employed. A431 cells were less affected compared to HaCaT cells, but the difference was not statistically significant. ROS production was not significant, except in HaCaT cells at the highest concentration. The comet assay revealed no significant supplementary DNA lesions, while the secretion of inflammatory cytokines was modulated by the presence of GNPs only when the cells were additionally irradiated with UVB. These results recommend GNPs-CM for further testing and possible dermatological applications.

Direct Methanol Fuel Cells have received great interest for portable applications and electric vehicles. Even if the development of new catalysts for fuel cell is always under consideration, the platinum-based ones remain the most used for these technologies. Metal-organic-frameworks (MOF) are noble-metal-free promising materials for fuel cell industry. Although HKUST-1 is not a very stable MOF in aqueous solutions, we prove that the growth from its mother solution over different linkers (mercaptoacetic and trimesic acids) lead to durable HKUST modified electrodes: Au_MAA_HKUST and Au_TA_HKUST. Self-assembling or electrochemical procedures are used to prepare the adlayers on gold electrode. Electrochemical experiments show that the current density obtained for the Au_MAA_HKUST is almost 28 times higher than that of bulk gold electrode. The Au_TA_HKUST electrode reveals a similar response regarding the potential range, but the current densities are lower. The possibility to form the trimesic acid (a component of HKUST-1) adlayer on gold electrode offers us the opportunity to investigate the mechanism of methanol oxidation on HKUST-1 regarding both the organic linker and metallic ions. It is worth noting that the role of trimesic acid in methanol oxidation is low comparing the CuII nodes from HKUST-1.

In the present paper, the reductive amination of a-ketoisocaproic acid to L-leucine was monitored using a new modified electrode based on gold nanoparticles (AuNPs) and leucine dehydrogenase (LeuDH). The modified electrode was prepared by self-assembling of AuNPs with thiocytosine followed by the immobilization of the enzyme. The enzyme-modified electrode response was investigated by chronoamperometry for indirect quantification of ammonium ion (NH4+) involved in the reaction. This reaction is catalyzed by LeuDH and takes place in the presence of ammonium chloride, as nitrogen source, and nicotinamide adenine dinucleotide (NADH), as cofactor. The enzyme-modified electrode was also used for in situ electrochemical NADH regeneration. After one step NADH regeneration the conversion of ammonium ion was improved. The modified electrode has good sensitivity (0.91 x 10(-3) A/M) and reproducibility with an RSD of 8.4% (n = 4). The experimental determination of ammonium ion was confirmed by standard Berthelot spectrophotometric method.

A test of Raman spectroscopy as a technique to diagnose inflammatory conditions and differentiate the effect of treatments with silver and gold nanoparticles conjugated with natural extracts compared with microscopy in experimental acute inflammation.

This work reports the preparation of water-soluble leucine capped gold nanoparticles by two single-step synthesis methods. The first procedure involves a citrate reduction approach where the citrate is used as reducing agent and leucine as capping/stabilizing agent. Different sizes of gold nanoparticles, citrate reduced and stabilized by leucine, Leu-AuNPs-C, with the mean diameters in the range of 21–56 nm, were obtained by varying the macroscopic parameters such as: concentration of the gold precursor solution, Au (III):citrate molar ratio and leucine pH. In the second procedure, leucine acts both as reducing and stabilizing agent, allowing us to obtain spherical gold nanoparticles, Leu-AuNPs, with a majority of 80 % (with the mean diameter of 63 nm). This proves that leucine is an appropriate reductant for the formation of water-soluble and stable gold nanoparticles colloids. The characterization of the leucine coated gold nanoparticles was carried out by TEM, UV–Vis and FT-IR analysis. The cytotoxic effect of Leu-AuNPs-C and Leu-AuNPs was also evaluated.

This research aimed at reporting the synthesis, characterization and evaluation of the anti-inflammatory effects of some new biomaterials based on silver nanoparticles and polyphenols rich natural extracts. A fast and eco-friendly extracellular biosynthesis of silver nanoparticles (AgNPs), using European black elderberry (Sambucus nigra - SN, Adoxaceae family) fruit extracts was developed. The phytosynthesized nanoparticles exhibited an absorbance peak at 426nm, characteristic for AgNPs and their sizes were ranged from 20 to 80nm. The anti-inflammatory properties of AgNPs were assessed in vitro on HaCaT cells exposed to UVB radiation, in vivo on acute inflammation model and in humans on psoriasis lesions. In vitro, our results demonstrated the anti-inflammatory effects of functionalized AgNPs by the decrease of cytokines production induced by UVB irradiation. In vivo, the pre-administration of AgNPs reduced the edema and cytokines levels in the paw tissues, early after the induction of inflammation. The present study also demonstrated the possible use of synthesized AgNPs for the treatment of psoriasis lesions.

In this paper we report the preparation of a modified electrode with gold nanoparticles and guanine. The colloidal suspension of gold nanoparticles was obtained by Turkevich method and was next analyzed by UV-Vis spectroscopy and Transmission Electron Microscopy (TEM). The gold electrode was modified by self-assembling the gold nanoparticles with guanine, the organic molecule playing also the role of linker. The electrochemical characteristics of the bare and modified electrode were investigated by Electrochemical Impedance Spectroscopy (EIS). A theoretical model was developed based on an electrical equivalent circuit which contain solution resistance (R-s), charge transfer resistance (R-ct), Warburg impedance (Z(W)) and double layer capacitance (C-dl).

Gold nanochains/nanowires were prepared by simultaneously reducing the gold salt in the presence of stabilizing biomolecules L-aspartate and L-lysine, Collagenthat acts as capping agent and as a template in the formation of two-dimensional gold nanostructures. L-aspartate and L-lysine were used in order to form nanochains due to their ability to cap gold nanoparticles through an oriented attachment mechanism that leads to the formation of one-dimensional nanostructures. The formation of the nanowires was controlled by reducing the gold salt onto the surface of the collagen template. Transmission electron microscopy (TEM) and x-ray powder diffraction were employed in order to demonstrate the morphological and structural properties of the nanowires. In order to provide evidence of the possible applications of gold nanostructures as biocompatible substrates for tissue engineering, mesenchymal stem cells were cultured in their presence. MTT proliferation assays, as well as immunohistochemistry assays, were performed. The experiments demonstrated that each nanostructure stimulates cell proliferation, but better results were obtained in the case of collagen. Moreover, we noticed that the nanostructures are tracked inside of the cells, most likely in the perinuclear region of the stem cells.

In the present paper we have investigated the pH influence on the morphology of some new hybrid materials based on gold nanoparticles and natural extracts from fruits of Romanian native plants of Adoxaceae family (Viburnum opulus L. and Sambucus nigra L.). It is well known that the natural plants extracts are beneficial for humans thanks to their antioxidant, anti-inflammatory and immunomodulatory effects. The biological activity of these berries is mainly due to their high content of anthocyanins and other polyphenols. The nanoparticles facilitate the penetration of substances in skin, enhancing their antimitotic, anti-inflammatory and antibiotic properties. We have chosen the optimal method to get these materials in which gold nanoparticles of 10-80 nm were obtained. We characterized them by UV-Vis and FT-IR spectroscopy, by TEM and DSC. Creams prepared with the hybrid materials have been tested on psoriatic lesions and the medical results emphasized a remarkable improvement in this diseases.

The present paper describes the preparation of new modified surfaces for electrodes based on guanine/thiocytosine and gold nanoparticles. The gold nanoparticles were analyzed by UV-vis spectroscopy and transmission electron microscopy (TEM) and it was found that they have diameters between 30 and 40 nm. The layers were characterized by specular reflectance infrared spectroscopy (FTIR-RAS) and by atomic force microscopy (AFM). The thickness of layers was found to be approximately 30 nm for TC layers and 300 nm for GU layers. Every layer was characterized as electrochemical sensor (by cyclic voltammetry) both for uric acid and ascorbic acid determinations, separately and in their mixture.The modified sensors have good calibration functions with good sensitivity (between 1.145 and 1.406 mA cm(-2)/decade), reproducibility (<1%) and good long-term stability (3 determinations in an interval time of 3 months). The best responses were obtained for gold_thiocytosine (Au_TC) and gold_guanine (Au_GU) layers. (C) 2012 Elsevier Ltd. All rights reserved.

The main purpose of the present paper is to emphasize the non-invasive effect of some new prepared nanomaterials on skin diseases (psoriasis) together with the procedures to obtain them. These new materials are based on gold nanoparticles and natural compounds extracted from native plants of the Adoxaceae family (European cranberrybush - Viburnum opulus L. and European black elderberry - Sambucus nigra L.) and possess a known anti-inflammatory activity mainly due to their high content of anthocyanins and other polyphenols. The nanomaterials were characterized by transmission electron microscopy (TEM), UV-Vis spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and thermogravimetric analysis (TGA). Studies in vivo and in vitro were made in order to determine the toxicity of the products. Based on the obtained nanomaterials, specific dermatological creams were prepared. Their effect on psoriatic lesions, in comparison with the hydrocortisone creams, was studied.

The low rate of survival for patients diagnosed with glioblastoma may be attributed to the existence of a subpopulation of cancer stem cells. These stem cells have certain properties that enable them to resist chemotherapeutic agents and ionizing radiation. Herein, we show that temozolomide-loaded gold nanostructures are efficient in reducing chemoresistance and destroy 82.7% of cancer stem cells compared with a 42% destruction rate using temozolomide alone. Measurements of in vitro cytotoxicity and apoptosis indicate that combination with gold facilitated the ability of temozolomide, an alkylating drug, to alter the resistance of these cancer stem cells, suggesting a new chemotherapy strategy for patients diagnosed with inoperable recurrent malignant glioma.

In this paper we have investigated two approaches for preparation of 1D and 2D nanostructures using amino acids either for capping or as linker to a substrate. In particular we have exploited the binding ability of L-lysine, a polar amino acid which favors the self-assembling of gold nanoparticles into nanochains. The zwitterionic properties of this amino acid create a net dipole moment on the nanoparticles surface. Consequently, adjacent nanoparticles fuse through an oriented attachment mechanism and form 'peanut-shape' particles which in time develop into extended one-dimensional nanostructures. The morphological characteristics of gold nanowires were investigated by TEM and HR-TEM. Besides such 1D nanostructures, we have designed a novel 2D nanostructured assembly based on polyglutamic acid/cysteine/gold nanoparticles layer, linked to the surface of a glassy carbon electrode. Morphological and electrochemical characteristics of this assembly were investigated by Atomic Force Microscopy (AFM) and Electrochemical Impedance Spectroscopy (EIS).

A novel modified electrode was designed and fabricated by linking L-Leucine capped gold nanopartides to 1,3-propanedithiol self-assembled monolayer (SAM), on gold substrate. Using UV-Vis and FT-IR spectroscopy, we have shown that L-Leucine molecules functionalize the gold nanoparticles. Morphological characteristics of capped nanoparticles before and after linking to SAM were evidenced by TEM and tapping (TM) mode AFM. The properties of the nanostructured assembly were tested for detection of Cu(II) ions, by employing cyclic voltammetry as investigation techniques. A detection limit of 5.4 x 10(-7) M was obtained in this case. The results were compared with those obtained for bare gold electrode or modified by citrate-capped gold nanoparticles.Additionally, Electrochemical Impedance Spectroscopy was used to further characterize the electrode modified with L-Leucine capped gold nanoparticles. An equivalent electrical circuit was developed to interpret and fit the experimental EIS data. The circuit contains the solution resistance (R-5), the charge-transfer resistance (R-ct), the Warburg impedance (Z(Wt) - transmissive boundary) and a constant phase element (CPE) that models the behavior of the double-layer capacitance. The charge-transfer resistance was found to vary with Cu(II) concentration within 10(-5) to 10(-3) M concentration range; a saturation tendency was observed at higher concentrations. (C) 2012 Elsevier Ltd. All rights reserved.