Search

This work aims at designing through a �green� bottom-up strategy, four types of bio-based systems containing artificial cell membranes (with or without vitamin C) and silver nanoparticles (AgNPs) phyto-generated from aqueous extract of Arctium lappa leaves. The �green� approaches for AgNP synthesis, by using the vast bioreducing potential of plants are low-cost and eco-friendly procedures.Exploiting vegetal wastes as precursors for phyto-metallic nanoparticles has received attention from scientific community in the last years due to its significant economic and environmental impacts. UV-Vis absorption spectra demonstrated the biosynthesis of metallic nanoparticles which exhibited a strong SPR peak located at 437 nm wavelengths. The formation of the biocomposites containing the �green� synthesized AgNPs has been demonstrated by UV-Vis absorption spectroscopy and Dynamic Light Scattering measurements. DLS results highlighted the nanoscale size of the prepared �green� AgNPs. The physical stability of the obtained silver-based systems was evaluated through zeta potential values, based on electrophoretic mobility. The systems loaded with vitamin C proved to be more stable and showed enhanced antioxidant activities (between 72.3% to 88% evaluated by chemiluminescence technique). Our results demonstrated that these developed silver-based biogenic systems generated from Arctium lappa leaves could be used as antioxidant agents in various biomedical applications.

Huge amounts of vegetable waste, mainly resulting from the food industry, need large areas for storage, as they could cause hazardous environmental impact, leading to soil and water pollution or to CO2 emissions during accidental incineration. This work was aimed at recycling certain lignocellulosic waste (walnut shells, kernels of peach, apricot, and olive) to design advanced carbon material precursors (ACMP) to be used for obtaining nano-powders with high applicative potential in pollution abatement. Both waste and ACMP were characterized using proximate and elemental analysis, and by optical microscopy. Complex characterization of raw materials by FTIR, TGA-DTG, and SEM analysis were carried out. The ACMP were synthetized at 600–700 °C by innovative microwave heating technology which offers the advantages of lower energy consumption using 3.3 kW equipment at laboratory level. The ACMP ash < 3% and increased carbon content of 87% enabled the development of an extended pore network depending on degassing conditions during heating. TEM analysis revealed a well-developed porous structure of the synthesized ACMP carbonaceous materials. Due to the presence of oxygen functional groups, ACMPs exhibit adsorption properties highlighted by an iodine index of max. 500 mg/g and surface area BET of 300 m2/g, which make them attractive for removal of environmental pollutants such as dyes having molecule sizes below 2 nm and ions with pore dimensions below 1 nm, widely used industrially and found in underground waters (NO3−) or waste waters (SO42−).

This work is focused on obtaining antioxidant materials based on liposomes and silver nanoparticles (AgNPs). The lipid vesicles labeled with chlorophyll a (as a spectral marker) were prepared by li...

The three copper complexes having a-ketoglutaric acid (H2A) and 1- (o-tolyl) biguanide (TB) ligands have been synthesized and characterized. The proposed formulas for these complexes are: [Cu(TB)(HA)]Cl (C1), [Cu(TB)(HA)CH3COO]�H2O (C2) and [Cu(TB)(HA)](NO3) (C3) where HA represents deprotonated H2A. The complexes obtained were tested for antibacterial activity against Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853, antifungal activity on Candida albicans ATCC 10231 and antitumor activity on HeLa tumor cells. Due to the antitumor, antifungal, antimicrobial activity and inhibition of inert substrate adhesion, complexes synthesized could be used for potential therapeutic applications.

In this study, hydroxyapatite (HAp) obtained by hydrothermal synthesis from natural sources (whelk shells of Rapana thomasiana) was compared to synthetic hydroxyapatite (prepared from chemical reagents) and used for 3D printing of HAp-based structures. Rapana thomasiana can be found in Romanian coast of Black Sea. The visceral part of Rapana is used for culinary purposes, but the whelk shell, mainly consisting of CaCO3, remains as biowaste and can be used as a source of Ca for hydroxyapatite synthesis. Synthetic and natural hydroxyapatite nanopowders were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), dynamic light scattering (DLS) method and in vitro tests. XRD and FT-IR have confirmed the formation of nanostructured hydroxyapatite irrespective of the raw material used. Both types of powders were further used for 3D printing of HAp-based structures, which have also been characterized by SEM and in vitro tests. In vitro tests performed on natural HAp disks (made from whelk shell) lack cytotoxicity and were associated with cell viability similar to that for the synthetic hydroxyapatite disk.

We present a comparative study on a 700-yr sequence of dendrochronologically ordered tree-rings of Pinus cembra originating from Eastern Carpathians for the period AD 1009–1709. This period covers the solar minima of the Little Ice Age. The aim of this study was to assess the accuracy of our radiocarbon (14C) determinations interpreted on the IntCal13 calibration data and to observe any apparent offsets. The 14C measurements on single and double tree-rings were “wiggle-matched” to secure the dendrochronology cross-matching of all the Pinus cembra wood pieces. The results showed a very good agreement between the age datasets for four out of five wood trunks. However, for one of them a new cross-matching was performed after a quality assurance test, establishing an earlier 48-yr position, recommended by wiggle-matching Bayesian statistics and dendrochronological analysis. Following this adjustment, the quantification of the 14C level variability with respect to the IntCal13 calibration curve was obtained by calculating Δ14C for all tree-ring samples. As a final conclusion, an insignificant 14C concentration offset of –0.63 ± 3.76‰ was found for the Romanian samples.

The main purpose of the present research was to test the ability of nanostructured lipid carriers (NLCs) to efficiently host a hydrophilic polyphenol active with health-promoting activities (caffeic acid (CA)). The caffeic acid-loaded lipid nanocarriers (CA-NLCs) were obtained by high-pressure homogenization technique using a surfactant mixture of Tween 20 and L-α-phosphatidylcholine in association with a lipid mixture of linseed oil, hexadecyl palmitate, and glycerol monostearate. In the first stage, the proportion between surfactant mixture and lipid phase has been varied to obtain appropriate stable nanocarriers. The optimized NLCs have been further loaded with different amounts of caffeic acid and were analyzed in terms of physical stability, size characteristics, and encapsulation efficiency. The antioxidant activity of CA-loaded NLCs and their release behavior have been tested by specific in vitro methods, e.g., ABTS (2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) assay and release experiments, by Franz cell diffusion. The ABTS assay highlighted a high antioxidant potential of the caffeic acid in association with linseed oil. The capacity to capture ABTS cationic radicals was superior for the NLC entrapping an initial amount of 1.5% CA, the level of antioxidant capacity being 91.3%. The in vitro release experiments showed a different release behavior, depending on the initial amount of caffeic acid used. NLC loaded with a higher concentration of CA manifests a gradual slow release, e.g., 45% CA after 24 h of in vitro experiments, while the NLC loaded with smaller concentration of CA assured a higher release in time, around 65%.

This paper presents the development of dynamically cured polymer composites and nanocomposites based on plastomer - PP (polypropylene) and EPDM elastomer (ethylene-propylene-diene-terpolymer) compatibilized and reinforced with nanometric particles-MMT (montmorillonite, chemically modified layered clay) in two stages, by extrusion-granulation and mixing. Nanoparticles increase the thermal resistance of dynamically cured polymer nanocomposites. By means of compatibilization and dynamic curing, elastomer particles - EPDM are more easily dispersed in the mixture. The materials obtained were tested physicomechanically (Melt Flow Index) and morpho-structurally (FT-IR and DSC).

A comprehensive study has been carried out to evaluate the extraction of heavy metals mixture (Co2+, Cr3+, Cu2+, Ni2+) from aqueous media by Winsor II non-ionic microemulsion, containing polyoxyethylene (4) lauryl ether as non-ionic surfactant and butyl acetate as organic phase. The extraction mechanism is based on the formation of thiocyanate complexes of metals and their transfer from aqueous to microemulsion phase, either towards the interfacial film of surfactant (Co2+) or into the core of micelles (Cr3+, Cu2+, Ni2+). The value of the distribution coefficient for Co2+ was higher than for the other studied metals and its extraction efficiency was not dependent on the working conditions, showing a maximum value (99.99%) in all cases. By using successive extractions, chromium, nickel and copper ions that remained in the aqueous phase after first extraction were transported into the microemulsion phase, leading to an increase in the extraction efficiency up to 99.99% for chromium and copper, and 85% for nickel. Based on pH influence, a selective extraction of Co2+ and Cr3+ can be achieved, since the cobalt ions were completely extracted into the microemulsion phase at pH = 1, and the chromium ions still remained in the aqueous phase. Keywords: Nonionic microemulsion, Thiocyanate complexes of heavy metals, Simultaneous heavy metals extraction, Microinterfacial effect, Synergism

The treatment of wastewaters with complex load including dyes and heavy metals is a subject of paramount importance since trace amounts of these compounds lead to an enormous pollution problem. The present research proposes an innovative, fast and efficient microemulsion system for simultaneous extraction of a mixture of dyes (Crystal violet and Rhodamine B) and heavy metals (cobalt(II) and copper(II) ions) from such wastewaters. The used microemulsion is an environmental friendly system containing Brij 30 as nonionic surfactant and butyl acetate as organic phase. The effect of various parameters with significant influence on the dye and metals extraction efficiencies has been investigated in order to find out the optimal compositions for an efficient extraction of dyes – heavy metals mixture from aqueous media. The results show that the optimum extraction conditions for this system corresponds to pH = 5, a water to oil volumetric ratio equal to 9 and a concentration of the complexing agent equal to 2 mol/L.

The paper aims at testing an innovative organic fertilizer obtained from waste by processing a mixture of marine algae biomass, sewage municipal sludge and farmyard manure. Design of this polycomposite fertilizer is based on adequate conceptual and experimental models by taking into account the complex interactions among these three biomasses. In the first step a detail physico-chemical analysis has been performed on the composition of the three raw materials and also on the soil. In the second phase similar analyses have been carried out on representative samples of soil treated with the compost as compared with untreated soil samples. Analytical methods applied were FT-IR spectroscopy in correlation with organic/inorganic and total carbon (TOC/TIC/TC) analysis. The efficiency of applying this compost on the field at large scale has been assessed by means of fatty acid content of the oleaginous plants cultivated. Based on correlation between production quality and chemical composition of the composted soil, the optimal proportions of the mixture of the three organic wastes will be selected for designing an eco-friendly fertilizer able to improve agrochemical properties of the soil.

This work reports the semiquantitative laboratory chemical procedures developed for some Rare Earth Elements (REE) extraction and concentration from coal bottom ash (BA), including recycling the recovered valuable components. This preliminary assessment applied in case of 25 coal BA samples of Ceplea Valley landfill of Romania describes the chemical methods by using digestion with nitric acid coupled with microemulsion assisted extraction procedure. The enrichment of REE by concentrated nitric acid followed by water washing proved to be an adequate approach since water recovers 29.42% of metals comparing to that extracted by the total phase (ac + aq). The REE concentration process achieved by precipitation with NaOH, at different pH values, shows to be almost completely in the fraction at pH ≈ 0 and 3. The statistical outlook coefficient Coutl shows that evaluation of REE concentration in acid/aqueous solution falls into the “promising” field for their recovery by chemical procedures. Optimal microextraction was obtained by coupling microemulsion Winsor II ternary system consisting in Brij 30/AcOEt:AcOBu/metal ions solution, with citric acid as complexing agent. Results confirm that recovery of lanthanides as nanoparticles from microemulsion system yields over 85%. Optical characterization of oxide nanoparticles suggested applications such as for energy efficient buildings, photo-catalysts for water remediation or thin films for photonic optical devices. The ash residue can be also recycled as an alternative raw material for building materials production.

The efficiency of a new eco-friendly microemulsion system based on Polyoxyethylene (4) Lauryl ether/Butyl acetate/Water was compared to that of Polyoxyethylene (4) Lauryl ether/Ethyl acetate/Water. The two systems were analyzed with respects to the recovery of monocomponent or multicomponent targeted hydrophilic compounds (Crystal Violet dye and Co2+ ions) from polluted liquid media. In order to determine the optimal recovery conditions, the influence of surfactant and dye concentrations on the volumetric ratio of aqueous phase to microemulsion (F) was studied. Furthermore, heavy metal concentrations and distribution coefficients were analyzed using the ternary and pseudo-ternary phase diagrams. The results showed that the Polyoxyethylene (4) Lauryl ether/Butyl acetate/Water system was more efficient compared to the Polyoxyethylene (4) Lauryl ether/Ethyl acetate/Water system in the recovery of hydrophilic compounds for both monocomponent (Crystal Violet dye or Co2+) and multicomponent (Crystal Violet dye and Co2+) systems. A recovery efficiency of 90.6% for dye and heavy metal ions was obtained using the Polyoxyethylene (4) Lauryl ether/Butyl acetate/Water microemulsion system.

This paper proposes an innovative solution for the efficient dye degradation from water treatment plant effluent, using microemulsion assisted photodegradation without the addition of a solid catalyst. Total photodegradation of dyes was achieved using for the first time a process based on combined photocatalytic effects of the water/oil interface processes and the potential activity of ethyl acetate as a UV initiator. The catalytic effect of nanostructured fluids based on the carboxylic oil phase is an absolute scientific premiere, and microemulsion assisted photodegradation processes open a new direction to pollutants photodegradation approach, exceeding the performances of both homogeneous and heterogeneous catalysis. The phenomenological modeling, with and without initiator, on both homogeneous and heterogeneous systems showed that the photodegradation of cationic and anionic dyes in a water/nonionic surfactant/ethyl acetate microemulsion is a radical process based on a chain reaction scheme. The compl...

This study aimed to examine the efficiency of novel bioactive nanostructures represented by silica–titania sieves used as carriers for a new antibacterial agent izohidrafural against bacterial strains isolated from nosocomial urinary tract infections, by using biological quantitative assays. Several release trials have been established and compared with MCM-41 in parallel experiments to achieve the optimum release profile. The obtained systems showed that silica–titania sieves loaded with izohidrafural proved to be the most active material against Klebsiella pneumoniae (average minimal inhibitory concentration [MIC] 40.62 μg/mL), desaminase-positive strains (average MIC 2.925 μg/mL), and Proteus mirabilis (average MIC 9.37 μg/mL), the last being reported with the highest growth rate in the urinary tract catheters. In contrast, the nonloaded silica–titanium sieves exhibited the highest antimicrobial activity against the Gram-positive cocci. Izohidrafural exhibited the highest antimicrobial efficiency, superior to the common drug nitrofurantoin against most Escherichia coli strains, with average MIC of 4.68 μg/mL.

Bone grafts are used in a wide array of clinical settings to augment bone repair and regeneration. This article reports a new method for the elaboration of a hybrid biomaterial in the form of sponge based on collagen gel, CaCO3 from recycled Rapana thomasiana seashell, and Na2HPO4·2H2O. Practically, collagen acts as a matrix through which calcium and phosphate ions are diffusing during in situ hydroxyapatite synthesis. The organic–inorganic interactions among biomaterial components have been studied by infrared spectroscopy, and the surface morphology was investigated by scanning electron microscopy technique. Moreover, the developed biomaterials were studied for in vitro biocompatibility with MG63 human osteoblasts. The results obtained demonstrated that the developed hybrid material does not exhibit a significant cytotoxicity and supports cell proliferation. Consequently, it holds great promise for applications in bone tissue engineering.

A class of fluorescent Au@SiO2 and SiO2@Au core–shell fluorescent nanoparticles has been synthesized using microemulsion assisted sol–gel method coupled with photoreduction reaction as an easy, rapid and versatile “one-pot” procedure. In the case of Au@SiO2-RhB (gold nanoparticles core coated with silica-Rhodamine B shell) different silica shell sizes were obtained ranging from 3 to 116 nm, while for RhB-SiO2@Au (Rhodamine B-silica core coated with gold nanoparticles shell) the size of gold shell falls within 3–38 nm interval. The synthesized core–shell nanoparticles have been characterized by a variety of techniques including Dynamic Light Scattering (DLS), High-Resolution Transmission Electron Microscopy (HR-TEM) coupled with Energy-Dispersive X-ray spectroscopy (EDX), Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD) and UV–VIS–NIR spectroscopy to confirm the size, shape, stability and topographic structure of the both core–shell nanostructures. The fluorescence enhancement of Rhodamine B (RhB) dye in the presence of gold nanoparticles (AuNPs) was demonstrated for the core–shell nanostructures synthesized in the present study, for different silica or gold shells. These interesting fluorescent core–shell nanoparticles provide ideal candidates for a variety of applications in materials science, biology, catalysis and optical fields.

The growing scientific interest in exploitation of vegetable bioactives has raised a number of questions regarding their imminent presence in pharmaceutical formulations. This study intends to demonstrate that a dual combination between vegetable oil (e.g. thistle oil, safflower oil, sea buckthorn oil) and a carrot extract represents an optimal approach to formulate safe carrier systems that manifest cell regeneration effect and promising antioxidant and anti-inflammatory activity. Inclusion of both natural actives into lipid carriers imparted a strong negative charge on the nanocarrier surface (up to -45mV) and displayed average sizes of 70nm to 140nm. The entrapment efficiency of carrot extract into nanostructured carriers ranged between 78.3 and 88.3%. The in vitro release study has demonstrated that the entrapment of the extract represents a viable way for an equilibrated release of carotenoids. Besides the excellent antioxidant properties (e.g. scavenging up to 98% of the free oxygen radicals), the results of cellular integrity (e.g. cell viability of 133%) recommend these nanocarriers based on dual carrot extract-bioactive oil as a promising trend for the treatment of certain disorders in which oxidative stress plays a prominent role. In addition, the lipid nanocarriers based on safflower oil and sea buckthorn oil demonstrated an anti-inflammatory effect on LPS induced THP-1 macrophages, by inhibiting the secretion of two pro-inflammatory cytokines, IL-6 and TNF-α.

Incorporating noble metal nanoparticles (NPs) and oxides has been proved to be an effective method to tune the optical properties of silica based materials. In this paper the optical and photocatalytic properties have been studied for ZnO/SiO 2 modified with Au or NiO nanoparticles. Changes in the optical properties of semiconductor ZnO particles have been observed due to the deposition of coloured Au and NiO nanoparticles by reducing the band gap energy and thus extending light absorption to visible domain. The excellent surface characteristics of NiO/ZnO/SiO 2 and Au/ZnO/SiO 2 favour the adsorption behaviour of these materials and limit the recombination of electron–holes pairs. Crystal Violet degradation under VIS light proved to have higher efficiency in the presence of Au/ZnO/SiO 2 (97%) than for NiO/ZnO/SiO 2 (60%).

Effective low cost photoactive adsorbent materials (∼90% efficiency, 0–60 mg L−1 dye loading), under sunlight irradiation, at a very low content of functional components (0.13% ZnO and 0.02% Au), were designed by incorporating ZnO and Au nanoparticles as synergistic couple in silica matrix. The tandem Au/ZnO dispersed into silica matrix formed a Schottky barrier in this type of structure and thus the band gap energy was reduced to 2.25 eV and the photocatalytic activity under visible light irradiation was increased. Highly homogeneous distribution of ZnO quantum dots (4 nm) and gold plasmons (7 nm) into the silica matrix, by a convenient “one-pot” synthesis way, namely microemulsion assisted sol–gel procedure was reported. The study of how the Au/ZnO ratio (0.01/1, 0.1/1 and 1/1) affects the silica based materials activity was evaluated and the optimal Au/ZnO ratio (0.1/1) was established. The silica network formed around the Au and ZnO nanoparticles which were confined within the microemulsions colloidal aggregates, improved the stability of the final materials in different environments and the direct contact between dye and Au–ZnO couple. Tandem adsorption and photodegradation processes, following a first order kinetics, described the path ways and mechanism of interaction between dye molecules and materials surface.

This book is a reference work focused on the role and interactions of nanoparticles and free radicals that are responsible for oxidative and endoplasmic reticulum (ER) stresses, with deep insights into the intimate mechanisms of their ecotoxicology, cytotoxicity, nanotoxicity, and genotoxicity.

The association of numerous advantages of natural active compounds (from vegetal and herbs) and endogenous lipid in the same delivery system is a straightforward approach for the development of safe and better tolerated anti-obesity therapy. In the present study we envisage a novel concept for obesity therapy, devoted to the development of innovative lipid nanostructured formulas with improved gastric tolerability and enhanced specificity in adipose cells targeting. For this purpose, an anti-obesity herbal active from red pepper extract – Capsaicin (Cap) and an endogenous lipid regulator of appetite – oleoylethanolamide (OEA) or a structural analogue of OEA – Phenylalaninol oleamide (PAO), are simultaneously integrated within the same delivery system – nanostructured lipid carriers (NLC) prepared with linseed oil that has anti-inflammatory and hypotriglyceridemic properties. The NLC-OEA/PAO-Cap presented mean diameters under 200 nm, size that allow an efficient uptake of actives by enterocytes and lead to an extended biological action of all actives – Cap, OEA/PAO and linolenic acid. NLC revealed a polidispersity index ranging from 0.16 to 0.22, which represents a narrow dispersion around mean size and suggests an adequate unimodal behavior. The two types of NLC co-loaded with Cap and OEA/PAO were both negatively charged, with zeta potentials of −42.8 mV and −58.5 mV that offered a guarantee for an excellent stability of NLC in time. Despite to the competition between the accommodations of both actives into the lipid core of nanocarriers, the entrapment efficiency exceeds 92% for OEA/PAO and is ranged between 71 and 82% for Cap. In the presence of NLC-OEA/PAO-Cap, ABTS+⁎ inhibition proceeded in a Capsaicin concentration dependent manner and was dependent on the type of NLC formulation. A remarkable radical-scavenging activity against ABTS+⁎ was determined for Cap and OEA based-NLC. The in vitro release demonstrated that NLC played an important role on the delay of Cap dissolution; the NLC have ensured a slow release of Cap, eg only 21% Cap was released after 24 h of in vitro experiments. The in vivo pharmacological evaluation has revealed that the NLC-OEA/PAO-Cap treatment resulted in a body weight decrease and improves the lipid and glucose profile, as compared to the obese mice batch. Obesity mice treated with NLC-OEA exhibited a weight loss of ~15% and ~10% weight loss for NLC-POA, after 10-days treatment. Administration of NLC-OEA/PAO-Cap to the Albino Swiss mice led to significant decrease of glucose level (e.g. 117.4 mg/dL for NLC-OEA-Cap treated mice versus 213.9 mg/dL for obese mice batch) and exhibited a desired decrease effect of triglyceride (e.g. 71.1 mg/dL for NLC-OEA-Cap versus 129.5, for obese batch). Moreover, the cholesterol values have been lowered to almost half from the value determined for the control batches. Overall, study highlights that using appropriate lipid mediators in association with an herbal anti-obesity active, both formulated into lipid nanocarriers, could enhance the therapeutic response in the obesity treatment.

Pollution abatement of wastewaters discharged from textile industry remained a serious environmental problem susceptible for further technological improvements. This study proposes an innovative, fast and efficient microemulsion system for removal of ionic dyes mixture from such wastewaters. A series of physical–chemical parameters (initial dye concentration, pH, salt and sequestrant concentrations) with significant influence on the dye removal efficiency of water/nonionic surfactant/ethyl acetate ternary system has been studied in order to find out the optimal compositions for an efficient extraction of cationic and anionic dyes from aqueous media. The optimum extraction conditions for this system correspond to pH > 5, surfactant concentration around 8% (w/w) and organic phase concentration around 13% (w/w), resulting in extraction efficiencies around 90%. By adding sodium chloride (concentration > 60 g/L) in the ternary system the removal efficiency was improved.

The interactions of two ionic dyes, Crystal Violet and Methyl Orange, with different charged surfactants and also with a nonionic surfactant were investigated using surface tension measurements and visible spectroscopy in pre-micellar and post-micellar regions. It was found that for the water dominant phase systems the dye was localized between the polar heads, at the exterior of the direct micelle shells for all the systems. For the oil dominant phase systems, in case of the same charged dye/surfactant couples, the dye was localized in the micelle shell between the hydrocarbon chain of the surfactant nearby the hydrophilic head groups while for nonionic surfactant and oppositely charged dye/surfactant, localization of dye was between the oxyethylenic head groups towards the interior of the micelle core. Mixed aggregates of the dye and surfactant (below the critical micellar concentration of cationic surfactant), dye-surfactant ion pair and surfactant-micelles were present. The values of equilibrium constants (for TX-114/MO and TX-114/CV systems were 0.97 and 0.98, respectively), partition coefficients between the micellar and bulk water phases and standard free energy (for the nonionic systems were −12.59 kJ/mol for MO and −10.97 kJ/mol for CV) were calculated for all the studied systems. The partition processes were exothermic and occurred spontaneously.

The work aims to simulate in vitro the antioxidant activity of four phytoestrogen type isoflavones, whose effects are closer to those of estradiol (daidzein, formononetin, genistein, biochanin A) in biomimetic environments (in lecithin lipidic bi-layers and on silver nanoparticles), using the chemiluminescent system luminol–hydrogen peroxide, in phosphate buffer, pH 7.4. The contribution of a carrier protein, human serum albumin (HSA), to the antioxidant activity of these isoflavones has also been investigated. The rate of the fluorescence quenching of HSA by isoflavone as well as the binding constant of isoflavone to HSA, in both lecithin lipidic bi-layers and on silver nanoparticles, has also been investigated by fluorescence spectroscopy. The results are discussed with relevance to the oxidative stress process.

In this study, two issues commonly associated with phytochemical based nanotechnology were addressed: (1) the use of active compounds from medicinal herbs as functional ingredients entrapped into lipid-based nanocarriers; (2) the safety and efficacy of phytochemical-based nanocarriers with promising antioxidant and antitumor benefits. In this context, nanostructured lipid carriers (NLC) based on raspberry seed oil (Rso), pomegranate seed oil (Pso) and rice bran oil (Rbo) were synthesized and proven to be highly effective for the entrapment of hydrophilic ivy leaves extract (Ile). The size, morphology, zeta potential, entrapment efficiency and crystallinity of the Ile-loaded NLC were characterized. The effectiveness of Ile loaded-NLC has been proved by identifying a high capacity to scavenge free oxygen radicals (i.e. between 94 and 98%). 200 μg mL−1 Ile-NLC based on Rbo showed no significant effects on cellular viability in the fibroblast L929 cell line, while the tumor B16 cell line was markedly affected. MTS, RTCA assays and apoptosis examination revealed that these nanocarriers induce cytotoxicity and apoptosis in the murine melanoma B16 cell line. This study reports the first evidence of the association of hydrophilic and lipophilic phytochemicals in the same lipid nanocarriers, which appears to be a promising antioxidant and antitumor approach deserving further investigation.

The study describes an ideal approach to increase the co-encapsulation of two water and lipid-soluble drugs in the same delivery system. The main purpose is represented by the exploitation of oil fractions isolated from amaranth seeds for the development of squalene-based nanocarriers able for a dual release of one antitumor drug, pemetrexed and one bio-flavonoid, hesperidin. The co-encapsulated nanocarriers presented unique nanoassembly morphology and showed excellent stability against aggregation. A delimited repartition of both actives, mainly in oily nanoconfinements of lipid nanocariers has been indicated by scanning calorimetry. The entrapment efficiency study revealed a great encapsulation effect with values reaching 94% for hesperidin and 89% for pemetrexed. These values are associated with a high ability of squalene-nanocarriers to capture free radicals. The greatest antioxidant activity was determined for nanocarriers that co-encapsulate 1.4% drugs, e.g., 97.3 and 98.2%. In vitro co-release tests demonstrated that pemetrexed and hesperidin were gradually released despite of their different lipophilicity. The most concentrated squalene fraction assures a slower release of both actives. The cumulative results showed that the applied strategy is a promising approach to improve the performance of medical treatments used to prevent and treat diseases associated with tumor and oxidative stress.

The development of nano-dosage forms of phytochemicals represents a significant progress of the scientific approach in the biomedical research. The aim of this study was to assess the effectiveness of lipid nanocarriers based on natural oils (grape seed oil, fish oil and laurel leaf oil) in counteracting free radicals and combating certain tumor cells. No drug was encapsulated in the nanocarriers. The cytotoxic effect exerted by bioactive nanocarriers against two tumor cells, MDA-MB 231 and HeLa cell lines, and two normal cells, L929 and B16 cell lines, was measured using the MTT assay, while oxidative damage was assessed by measuring the total antioxidant activity using chemiluminescence analysis. The best performance was obtained for nanocarriers based on an association of grape seed and laurel leaf oils, with a capacity to scavenge about 98% oxygen free radicals. A dose of nanocarriers of 5mg·mL(-1) has led to a drastic decrease in tumor cell proliferation even in the absence of an antitumor drug (e.g. about 50% viability for MDA-MB 231 cell line and 60% viability for HeLa cell line). A comparative survival profile of normal and tumor cells, which were exposed to an effective dose of 2.5mg·mL(-1) lipid nanocarriers, has revealed a death rate of 20% for normal B16 cells and of 40% death rate for MDA-MB 231 and HeLa tumor cells. The results in this study imply that lipid nanocarriers based on grape seed oil in association with laurel leaf oil could be a candidate to reduce the delivery system toxicity and may significantly improve the therapeutic efficacy of antitumor drugs in clinical applications.

Drug delivery systems based on natural drug carriers have become important due to their non-toxicity and biodegradability. We report here the synthesis and characterization of new biomaterials like sponges containing collagen, chloramphenicol and glutaraldehyde for dentistry. All sponges favour water absorption, showing that increasing the glutaraldehyde content leads to an increase in water uptake. The sponges showed resistance to collagenase degradation and strong activity against the tested bacteria. Kinetic data showed non-Fickian diffusion behaviour with a slow release rate. Taking into account that dental drug delivery systems exhibit low water absorption, slow drug release, high content of drug delivery, good antimicrobial activity, and resistance to enzymatic action, the results obtained in this study indicate the optimal content of glutaraldehyde for the sponge as being 0.5%. The properties of the designed formulations demonstrate that these sponges could be adequate for the treatment and/or the prophylaxis of infected lesions at the dental level.

The combination of basil oil, natural antifungal, and nystatin has the potential to prevent the extension of topical fungal infections towards systemic infections. The aim of this study was to develop formulations based on basil oil and nystatin with the desired antifungal and antioxidant activity and low toxicity by using lipid nanocarriers. The synthesized nanocarriers showed spherical and homogeneous particles with main diameters less than 150 nm, as determined by TEM. The scanning calorimetric study revealed an imperfect crystallization in the core of lipid nanocarriers. Quantitative results suggested that basil oil concentration affects encapsulation efficiency. The prepared nanocarriers guaranteed an increased nystatin encapsulation by using 3% basil oil content. Chemiluminescence assay proved that the protective activity against oxygen free radicals was influenced by nystatin concentration. The in vitro antifungal studies revealed a better activity of the nanocarriers loaded with 1% nystatin in comparison with 0.5% loading.

Vegetable oils are well-known for their beneficial health effects, mainly due to their antioxidant activity, which is maintained or enhanced when they are encapsulated at nanoscale. This study aims to design new nanostructured lipid carriers (NLCs) containing various vegetable oils and their combinations in order to obtain efficient formulations with UV protection performance and antioxidant activity. Pomegranate seed oil, wheat germ oil, blackcurrant seed oil, sesame seed oil, carrot root oil, raspberry seed oil and rice bran oil were used for obtaining NLCs, as carriers for a photoprotective agent that absorbs the UVA radiation: diethylamino hydroxybenzoyl hexyl benzoate. The NLCs were characterized by mean particle size, physical stability over time, and entrapment efficiency of the UVA filter. The UV protection performance was assessed using both in vitro sun protection factor (SPF) and the UVA protection factor (UVAPF). The antioxidant activity was determined by chemiluminescence analysis. All vegetable oils used led to the development of appropriate NLCs, having mean particle sizes ranging between 100 nm and 145 nm and good physical stability with zeta potential values less negative than −35 mV. The UV protection factors were evaluated on the individual vegetable oils and on cream formulations based on NLCs. Out of the seven cream formulations, the best UV protection was assured by the pomegranate seed oil based cream resulting in a SPF of 4.1 and an UVAPF of 7.8. Knowing that a synergistic interaction can occur among the active compounds of different oils, new NLCs were developed by using a mixture of pomegranate seed oil and one of the other oils. The NLCs based on pomegranate seed oil combined with wheat germ oil have shown the best entrapment efficiency (70%) and photoprotection (SPF of 5.1 and a UVAPF of 9.5). All vegetable oils showed a good antioxidant activity, which was improved by their incorporation into NLCs. The results have shown that vegetable oils and especially their combinations can be used as renewable raw materials in designing effective and eco-friendly photoprotective nanostructured formulations.

The work aims to simulate in vitro the effects caused by oxidation of five hydroxyflavones (HF) (some typical models of flavonols), (3-HF, 6-HF, 7-HF, 3,6-diHF and 3,7-diHF) on silver nanoparticles (SNPs) using the chemiluminescent system luminol–hydrogen peroxide, in phosphate buffer, pH 7.4. The contribution of bovine and human serum albumins to the antioxidant activity of the mentioned flavones, and the effect on the SNPs support, in the chemiluminescent system luminol–hydrogen peroxide, has been also investigated. The results are discussed with relevance to the oxidative stress process.

This paper presents the spectral and electrochemical properties correlated to antioxidant character attributed to anthocyans: Pelargonidin-3-O-Glucoside, Cyanidin-3-O-Glucoside, Delphinidin-3-O-Glucoside, Peonidin-3-O-Glucoside, Malvidin-3-O-Glucoside. The Anthocyans were obtained and purified from natural selective hydroalcoholic extracts using HPLC chromatography. A series of determinations through the chemical voltammetry method were performed in view of identifying the anthocyanins’ oxidation and reduction potentials. These determinations were performed in electrochemical environments with different polarities and pH, in N, N-Dimethylformamide–Ethanol-Hydrochloric acid–Water systems. The results obtained offered data regarding the stability of anthocyans in the respective media. For Pelargonidin-3-O-Glucoside we performed detailed UV-VIS spectro-electrochemical measurements, using an optically transparent thin layer electrochemical cell. The results of these determinations offered information regardin...

The principal aim of the present study was to develop new safe and highly antioxidant nanostructured lipid carriers loaded with sea buckthorn extract. Three vegetable oils — grape seed oil, sea buckthorn oil and St. John's wort oil ( Hypericum perforatum oil) — were used as matrix components and the modified high shear homogenization technique has been employed for the synthesis of nanostructured materials. The effect of these oils on the antioxidant and antimicrobial activities of loaded sea buckthorn extract — nanostructured lipid carriers — has also been studied. For this purpose, a combination of two solid lipids: cetyl palmitate with glyceryl stearate and lecithin/block copolymer has been used. The obtained nanostructured lipid carriers have been characterized for the particle size and zeta potential by means of dynamic light scattering measurements. The nano-dimension morphology of loaded nanostructured lipid carriers was confirmed by transmission electron microscopy. Their crystallinity measured by differential scanning calorimetry has revealed a high disordered lipid matrix. The properties of sea-buckthorn-extract-loaded nanoparticles have been evaluated by an appropriate in vitro analysis (chemiluminescence method). The presence of the three vegetable oils influences extensively the antioxidant properties of the developed nano-formulations, as has been demonstrated using the chemiluminescence technique. The antimicrobial activity of the studied nanostructured lipid carriers, analyzed by the diffusion disc method, shows in most of the samples a high efficiency against Escherichia coli bacteria.

Due to their unique features, most nanostructured lipid carriers (NLCs) in association with vegetable oils that exhibit UV filtering properties and bioactivity could be used in many cosmetic formulations. Therefore, in this work, a new application of pomegranate seed oil (PSO) in the cosmetic sector was developed, based on the synthesis of bioactive lipid nanocarriers loaded with various UV filters by the hot high pressure homogenization technique. To get broad spectrum photoprotection, different UVA and UVB filters have been used (Avobenzone — AVO, Octocrylen-OCT, Bemotrizinol — BEMT). The influence of the solid lipids combined with PSO on the particle size, physical stability and entrapment efficiency was investigated using 8 nanocarrier systems. An improved physical stability and an appropriate size were obtained for NLCs prepared with Emulgade, carnauba wax and PSO (e.g. −30.9÷-36.9 mV and 160÷185 nm). NLCs showed an entrapment efficiency above 90% and assured slow release rates of UV filters, especially for BEMT (5%). The developed nanocarriers have been formulated into safe and effective sunscreens containing low amounts of synthetic UV filters coupled with a high percent of natural ingredients. The highest SPF of 34.3 was obtained for a cream comprising of 11% PSO and 3.7% BEMT

The vegetable oils and extracts known for their beneficial effects should be identified and used in various forms for the development of new healthy products. This study was designed to provide further investigation on new nanocarriers made with hempseed oil or a blend of amaranth and hempseed oils, for a concomitant encapsulation and release of the carotenoids enriched plant extract. The size of plant extract loaded lipid nanocarriers ranging between 109 and 130 nm was found to be less influenced by the different ratios of hempseed and amaranth oils. For all of the synthesized nanocarriers, zeta potential values were negative (−33.4 ÷ −38.1 mV). The scanning calorimetry study has shown that lipid nanocarriers have favorable lattice defects for plant extract encapsulation. Entrapment efficiency results revealed an increase of carotenoids entrapment from 57.6 to 83.5% as the amaranth oil percent has been increased. High ability to scavenge the free oxygenated radicals was distinguished for all free and loaded nanocarriers. The level of antioxidant activity increase was proportional to the extent of vegetable oil and was ranging between 93.4 and 98.1%. The nanocarriers made with amaranth and hempseed oils have shown a more sustained release over time than those prepared with hempseed oil only in association with solid lipids. Practical applications: The applicability of lipophilic plant extracts enriched in bioactive compounds encounters serious problems in the food and pharmaceutical sector due to poor bioavailability. Using the concept of exploiting natural resources in combination with soft nanotechnology, valuable bioactive vegetable mixtures could be formulated into solid colloidal nanoparticles. The bioavailability and the therapeutic benefit of hempseed and amaranth oils in association with lipophilic plant extract enriched in carotenoids are increased by incorporation into the same nanostructured formulation. These formulations result in unique precursors of health products, particularly for nutraceutical industry. The lipid nanocarriers based on natural compounds offer potential applications as natural, low cost and innovative delivery systems to improve quality and extend shelf-life of food products. The developed vegetable based lipid nanocarriers offer advantages of a minimum carrier cytotoxicity, good storage stability, synergistic effects, antioxidant and sustained release, easy to scale up production. Lipid nanocarriers made with hempseed and amaranth oils and loaded with carotenoids extract from marigold plant. Influence of vegetable oils on in vitro antioxidant activity of developed lipid nanocarriers.

After oxidation of tannins (Tannins 1–3) extracted from grape seeds, Tanoxil compounds with increased solubility and enhanced antioxidant activities were synthesized. In this research, ABTS+· assay and a chemiluminescence method were used for antioxidant measurement of hydrophilic compounds (Tanoxils 1–3).It was observed that the antioxidant activity (AA, %) is very similar for the three samples, while at the same time AA is quite high (93.16%–96.48%). The percentage of inhibition by ABTS+· is higher for Tanoxil 2 (96.4%) as compared to Tannin 2 compound (14.34%). Moreover, the total content (TCF) of carboxyl and phenolic groups was investigated. TCF values, determined for Tanoxil products, revealed a double (Tanoxil 1) or triple (Tanoxil 2) increase as compared to the value of the TCF of Tannin 1. Tanoxil products represent an interest for future research as they have a high AA (96.4%) and the content of acidic groups is significant (TCF, 0.191 meq g−1).

In this paper, the preparation and characterization of some novel nanostructured lipid carriers for drug delivery are reported. They are obtained by mixing two solid lipids, cetyl palmitate and glyceryl stearate, with three types of vegetable oils: grape seed oil, St. John's wort oil ( Hypericum perforatum oil) and sea buckthorn oil. In order to increase their antioxidant and antimicrobial properties, they are co-loaded with green tea extract by using a modified high shear homogenization technique. Size distribution and polydispersity index of the developed nanostructured lipid carriers determined by the dynamic light scattering, and corroborated with the results obtained by the transmission electron microscopy analysis, confirmed that the structures obtained are at nanoscales. The crystallinity behavior of the prepared nanostructured lipid carriers has been studied by differential scanning calorimetry; zeta potential measurements show that all loaded nanostructures present excellent physical stability. Their antioxidant and antimicrobial properties evaluated by an appropriate in vitro analysis using the chemiluminescence method, and the diffusion disc method, respectively, show that green tea extract could be utilized as a valuable natural source of antioxidant and antimicrobial agent. These new nano-formulations proved to have significant potential for nutritional and pharmaceutical applications.

A systematic study of the design and characterization of silica-microemulsion templates is presented. The ternary phase diagrams in micro-heterogeneous systems, by using a non-ionic surfactant (Brij 30) and different silica precursors (MTEOS, TEOS, PTEOS), have been drawn. Based on Khalweit diagrams, the phase inversion temperature was estimated as close to 315 K, for both alchil (TEOS) and aril (PTEOS) types of alcoxides. By correlating the information obtained from phase diagrams at room temperature with that of size effects revealed by VIS absorption molecular probes (bromthymol blue dye), the phase inversion point, i.e. the transition point from water-in-oil to oil-in-water microemulsion, was also clearly established as corresponding to R ∼ 1. Besides technically attractive features such as a wide variety of inorganic and hybrid nanomaterials, high specific surface and highly efficient applicative properties of the final materials, the approach of silica-microemulsion-based templates can be seen as a route towards the Green Chemistry concept.

The aim of this research was to develop advanced lipid nanocarriers based on renewable vegetable resources (rice bran oil and raspberry seed oil) that possess self-antioxidative properties, having advantages in terms of minimal side effects and exhibiting the ability to simultaneously co-encapsulate and co-release two active compounds. The focus has been oriented towards developing safe cosmetic formulations with broad-spectrum photoprotection based on these new lipid nanocarriers that contain large amounts of vegetable oils and low concentrations of synthetic UVA and UVB filters (butyl-methoxydibenzoylmethane - BMDBM and octocrylene - OCT). The lipid nanocarriers have a spherical shape and show good physical stability, with a zeta potential in the range of -25.5 to -32.4 mV. Both vegetable oils play a key role in the preparation of efficient nanocarriers, leading to a less ordered arrangement of the lipid core that offers many spaces for the entrapment of large amounts of BMDBM (79%) and OCT (90%), as wells as improved antioxidant activity and UV absorption properties, particularly for the lipid nanocarriers prepared from rice bran oil. By formulating the lipid nanocarriers into creams containing only 3.5% of the UV filters and 10.5% of the vegetable oils, the resulting sunscreens exhibited improved photoprotection, reflecting up to 91% and 93% of UVA and UVB rays, respectively. A new direction of research achieved by this study is the multiple release strategy of both UV filters from the same lipid nanocarrier. After 24 hours, a slow release of BMDBM (less than 4%) and OCT (17.5%) was obtained through a Fick diffusion process. This study demonstrates a significant advance in the areas of both nanotechnology and cosmetics, developing safer cosmetic formulations that possess broad antioxidant, photoprotective and co-release effectiveness due to the existence of a high content of nanostructured vegetable oils combined with a low amount of synthetic UV filters in the same carrier system.