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Liquid-phase oxidation of betulin extracted from birch bark was studied over gold catalysts supported on a range of supports (hydrotalcite, ZrO2, ZnO, MgO, CeO2, La2O3, HMS and various alumina) with different morphology and properties. Gold catalysts as well as the corresponding supports were characterized by XRD, BET, ICP-OES, XPS and TEM. It was found that the nature of the support plays a decisive role in betulin oxidation over gold-based catalysts, expressed in the influence on the average size and distribution of gold nanoparticles and, thereby, on their catalytic performance (activity and selectivity) in betulin oxidation. Moreover, it was revealed that betulin oxidation catalyzed by gold is a structure sensitive reaction, requiring an optimal size of gold nanoparticles of ca. 3.3 nm. The most suitable support for gold was found to be alumina. Kinetic studies allowed determination of reaction orders and conditions favorable for selective formation of a particular oxo-derivative of betulin (betulone, betulinic and betulonic aldehydes, betulinic acid).

Gold nanocatalysts, active in several oxidation reactions, suffer of insufficient time-on-stream stability. The easiest way to solve this problem is modifying the support, due to metal-support interaction. This study compares modifying effects of MgO and La2O3 on textural, electronic, and catalytic properties of Au nanoparticles (NPs) supported on inert nanostructured SiO2 in CO oxidation and liquid phase 1-octanol oxidation. Modification of the silica support surface with La and Mg increased metal support interaction, leading to gold particles with primary size of 1 nm but with different stability: stable under different pretreatment conditions on Mg-modified samples but highly sensible to the pretreatments on La-modified samples. Both modifiers changed electronic properties of supported gold favoring formation and stabilization of Auδ+ states, which are probable gold active sites in catalytic redox processes. Modification with La and Mg oxides changed catalytic properties in CO oxidation before and after pretreatment in H2 at 300 °C for 1 h. Gold catalysts supported on La- and Mg-modified silica showed similar performance in 1-octanol oxidation with higher conversion than unmodified Au/SiO2. La and Mg showed better promoting effects of catalytic properties in this reaction than redox modifiers (Fe and Ce) supported on small SiO2 particles.

Foot infections are difficult to eradicate, patients with diabetes mellitus among others are more susceptible to them, therefore preventive strategies and effective antimicrobial agents are needed. The antimicrobial properties of silver nanoparticles (AgNPs) are well known thus they are a trend for biomedical applications. The aim of this study was to investigate the antibacterial and antifungal activity of leather coated with AgNPs against two bacteria species Pseudomonas mendocina and Pseudomonas syringae, and the fungi Trichophyton mentagrophytes responsible for foot infections. Porcine leather was cut off and sprinkled with solutions containing various concentrations of metallic AgNPs. Inductively coupled plasma-atomic emission spectrometry (ICP-AES) and texture analysis of the leather were performed to quantify the silver metallic concentration metallic silver and to test the effect of AgNPs on leather softness. Antimicrobial activity was measured by agar diffusion test for zone of inhibition (ZoI). The textural analysis of the coated leather showed that the application of AgNPs diminished its softness in a concentration dependency manner. The results from the antimicrobial activity revealed that leather coated with 0.05% of metallic AgNPs had the best antibacterial effect. A decrease in the growth of T. mentagrophytes was observed on the leather coated with 0.25% of metallic AgNPs; however, this concentration was not enough to abolish fungal growing. In conclusion, the application of AgNPs to porcine leather decreased its softness but added beneficial antibacterial properties to avoid bacterial foot infections. Leather coated with AgNPs could be used as a suitable material to prevent foot infections and it could provide added value for shoes manufacturing.

The commercial dichloro(2-pyridinecarboxylato)gold(III) complex (1), anchored on different carbon materials, is reported for the first time as a catalyst in the cyclohexane hydrocarboxylation to cyclohexanecarboxylic acid. The reaction was carried out in the presence of CO and water, peroxodisulfate, at ca. 50 °C, with 1 in solution and anchored on carbon nanotubes, carbon xerogel or activated carbon, with three different surface chemistries: original forms (CNT, CX or AC, respectively), oxidized with HNO3 (-ox) or oxidized with HNO3 and subsequently treated with NaOH (-ox-Na). 1@CNT-ox-Na was the best catalyst, yielding up to 78% of cyclohexanecarboxylic with a selectivity of 99%. Recycling studies showed that the catalyst was stable up to 4 cycles, the first decrease (11%) on the hydrocarboxylation yield being observed on the 5th cycle. No leaching of gold was found into the solution. The hydrocarboxylation of other cycloalkanes (cyclopentane, cycloheptane and cyclooctane) was also tested in the best conditions found for cyclohexane, but the respective carboxylic acids were obtained in considerably lower yields, which can be explained by different stabilities of cycloalkyl radicals.

Introduction. Argyria is an acquired skin condition that appears after the exposure or consumption of silver, leading to blue or grey coloration of the skin and mucosa. The aim of the present work was to draw researchers’ attention to two aspects of the argyria that until now have not received enough consideration. They are: (1) the process of delivering silver compound from the gastrointestinal tract to the skin and (2) the possibility for silver chloride to participate in this process along with the silver proteinates. Methodology. Illustrative experiments included the observation of color change (visual and using UV-Vis spectrometry) under different light exposure conditions of silver chloride sol in a sweat-simulating solution, in vials and under pig skin (in direct contact). Results and Discussion. A hypothetical mechanism based on a perspiration system for delivering the silver compounds from the gastrointestinal tract to the skin for argyria was proposed. It was also proposed not to completely exclude the partial participation of silver chloride along with the silver proteinates in this process.

Nowadays, Huanglongbing (HLB) disease, commonly known as “yellow dragon disease”, affects citrus crops worldwide and has a devastating effect in the agro-industrial sector. Significant efforts have been made to fight the illness, but still, there is no effective treatment to eradicate the disease. This work is the first approach to evaluate the capacity of silver nanoparticles (AgNPs) to directly eradicate the bacteria responsible for Huanglongbing disease, Candidatus Liberibacter asiaticus (CLas), in the field. The AgNPs were administered by foliar sprinkling and trunk injection of 93 sick trees with remarkable results. Both methods produce an 80–90% decrease of bacterial titre, quantified by qRT-PCR in collected foliar tissue, compared with the control group. Scanning electron microscopy images show an essential reduction of starch accumulation in phloem vessels after AgNP treatments without evidence of bacteria in the analyzed samples. Compared with other effective methods that involve β-lactam antibiotics, the potency of AgNPs is 3 to 60-times higher when it is administered by foliar sprinkling and from 75 to 750-fold higher when the administration was by trunk-injection. All these results allow us to propose this AgNP formulation as a promising alternative for the treatment of infected trees in the field.

Zeolites are materials of undeniable importance for science and technology. Since the properties of zeolites can be tuned after the inclusion of additional chemical species into the zeolitic framework, it is necessary to study the nature of zeolites after modification with transition metals to understand the new properties that were obtained, and with this information, novel applications can be proposed. This paper reports a solvent-free approach for the rapid synthesis of zeolites modified with iron and/or iron oxide particles. The samples were characterized, and their electrical and magnetic properties were investigated.

Infectious bronchitis (IB) of chickens is a highly contagious disease characterized by damage of the respiratory system and reproductive organs in young animals caused by a virus of the genus Gamma coronavirus. The condition of the respiratory system caused by the IB virus in chickens has many similarities with the pathology of the respiratory system caused by SARS-CoV-2 in humans. The effectiveness of virucidal drugs (Argovit, Triviron, Ecocid, and lauric acid monoglyceride) was tested on chickens inoculated with a tenfold dose of a vaccine strain based on the attenuated virus H120 against IB of chickens. On the 6th day after inoculation, inflammatory changes in the intestines, lungs, and thymus were observed in the control group. The experimental groups were characterized by less pronounced inflammatory reactions and a lower proportion of thymus and lung probes containing genomic IB virus RNA. Since the virucidal activity of four orally administrated formulations was possible only in the intestine, the experimental data indirectly confirmed the hypothesis of the possibility of the predominant accumulation of coronaviruses in the intestine and subsequent lung damage due to the hematogenous redistribution of viral particles and IBV antigens. It was suggested that other coronaviruses including SARS-CoV-2 can implement a similar mechanism.

Silver nanoparticles (AgNPs) have been studied worldwide for their potential biomedical applications. Specifically, they are proposed as a novel alternative for cancer treatment. However, the determination of their cytotoxic and genotoxic effects continues to limit their application. The commercially available silver nanoparticle Argovit™ has shown antineoplastic, antiviral, antibacterial, and tissue regenerative properties, activities triggered by its capacity to promote the overproduction of reactive oxygen species (ROS). Therefore, in this work, we evaluated the genotoxic and cytotoxic potential of the Argovit™ formulation (average size: 35 nm) on BALB/c mice using the micronucleus in a peripheral blood erythrocytes model. Besides, we evaluated the capability of AgNPs to modulate the genotoxic effect induced by cyclophosphamide (CP) after the administration of the oncologic agent. To achieve this, 5–6-week-old male mice with a mean weight of 20.11 ± 2.38 g were treated with water as negative control (Group 1), an single intraperitoneal dose of CP (50 mg/kg of body weight, Group 2), a daily oral dose of AgNPs (6 mg/kg of weight, Group 3) for three consecutive days, or a combination of these treatment schemes: one day of CP doses (50 mg/kg of body weight) followed by three doses of AgNPs (one dose per day, Group 4) and three alternate doses of CP and AgNPs (six days of exposure, Group 5). Blood samples were taken just before the first administration (0 h) and every 24 h for seven days. Our results show that Argovit™ AgNPs induced no significant cytotoxic or acute genotoxic damage. The observed cumulative genotoxic damage in this model could be caused by the accumulation of AgNPs due to administered consecutive doses. Furthermore, the administration of AgNPs after 24 h of CP seems to have a protective effect on bone marrow and reduces by up to 50% the acute genotoxic damage induced by CP. However, this protection is not enough to counteract several doses of CP. To our knowledge, this is the first time that the exceptional chemoprotective capacity produced by a non-cytotoxic silver nanoparticle formulation against CP genotoxic damage has been reported. These findings raise the possibility of using AgNPs as an adjuvant agent with current treatments, reducing adverse effects.

SARS-CoV-2 infection in hospital areas is of a particular concern, since the close interaction between health care personnel and patients diagnosed with COVID-19, which allows virus to be easily spread between them and subsequently to their families and communities. Preventing SARS-CoV-2 infection among healthcare personnel is essential to reduce the frequency of infections and outbreaks during the pandemic considering that they work in high-risk areas. In this research, silver nanoparticles (AgNPs) were tested in vitro and shown to have an inhibitory effect on SARS-CoV-2 infection in cultured cells. Subsequently, we assess the effects of mouthwash and nose rinse with ARGOVIT® silver nanoparticles (AgNPs), in the prevention of SARS-CoV-2 contagion in health workers consider as high-risk group of acquiring the infection in the General Tijuana Hospital, Mexico, a hospital for the exclusive recruitment of patients diagnosed with COVID-19. We present a prospective randomized study of 231 participants that was carried out for 9 weeks (during the declaration of a pandemic). The "experimental" group was instructed to do mouthwash and nose rinse with the AgNPs solution; the "control" group was instructed to do mouthwashes and nose rinse in a conventional way. The incidence of SARS-CoV-2 infection was significantly lower in the "experimental" group (two participants of 114, 1.8%) compared to the "control" group (thirty-three participants of 117, 28.2%), with an 84.8% efficiency. We conclude that the mouth and nasal rinse with AgNPs helps in the prevention of SARS-CoV-2 infection in health personnel who are exposed to patients diagnosed with COVID-19.

Thein vitroantiviral effect of AgNPs had been previously demonstrated as well as its toxicity in cells is known. Therefore, before studying its capacity to inhibit SARS-CoV-2, Vero E6 cell viability in the presence of AgNPs was studied. Two-fold serial dilutions of Argovit were added to Vero E6 monolayers and their viability was measured using a MTS Cell Proliferation Assay kit. MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium) is a metabolic dye that relies on the conversion of soluble tetrazolium by bioreduction into a colored formazan product that is soluble in tissue culture medium. Once the concentration that is not toxic for Vero E6 cells was stablished, anin vitroinhibition assay was carried out, in which we confirmed that low non-toxic concentrations of AgNPs have an antiviral capacity against SARS-CoV-2.

Silver nanoparticles (AgNPs) not only have shown remarkable results as antimicrobial and antiviral agents but also as antitumor agents. This work reports the complete characterization of five polyvinylpyrrolidone-coated AgNP (PVP-AgNP) formulations, their cytotoxic activity against human colon tumor cells (HCT-15), their cytotoxic effect on primary mouse cultures, and their lethal dose on BALB/c mice. The evaluated AgNP formulations have a composition within the ranges Ag: 1.14–1.32% w/w, PVP: 19.6–24.5% and H2O: 74.2–79.2% with predominant spherical shape within an average size range of 16–30 nm according to transmission electron microscopy (TEM). All formulations assessed increase mitochondrial ROS concentration and induce apoptosis as the leading death pathway on HCT-15 cells. Except for AgNP1, the growth inhibition potency of AgNP formulations of human colon tumor cancer cells (HCT-15) is 34.5 times higher than carboplatin, one of the first-line chemotherapy agents. Nevertheless, 5–10% of necrotic events, even at the lower concentration evaluated, were observed. The cytotoxic selectivity was confirmed by evaluating the cytotoxic effect on aorta, spleen, heart, liver, and kidney primary cultures from BALB/c mice. Despite the cytotoxic effects observed in vitro, the lethal dose and histopathological analysis showed the low toxicity of these formulations (all of them on Category 4 of the Globally Harmonized System of Classification and Labelling of Chemicals) and minor damage observed on analyzed organs. The results provide an additional example of the rational design of safety nanomaterials with antitumor potency and urge further experiments to complete the preclinical studies for these AgNP formulations.

42-01-09/169/2021-4 CTQ2017-86170-R Au and Ag were deposited on TiO2 modified with Ce, La, Fe or Mg in order to obtain bimetallic catalysts to be used for liquid-phase oxidation of 1-octanol. The effects of the deposition order of gold and silver, and the nature of the support modifying additives and redox pretreatments on the catalytic properties of the bimetallic Au-Ag catalysts were studied. Catalysts were characterized by low-temperature nitrogen adsorption–desorption, energy dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy and ultraviolet-visible diffuse reflectance spectroscopy. It was found that pretreatments with hydrogen and oxygen at 300◦C significantly decreased the activity of AuAg catalysts (silver was deposited first) and had little effect on the catalytic properties of AgAu samples (gold was deposited first). The density functional theory method demonstrated that the adsorption energy of 1-octanol increased for all positively charged AuxAgyq (x + y = 10, with a charge of q = 0 or +1) clusters compared with the neutral counterparts. Lanthanum oxide was a very effective promoter for both monometallic and bimetallic gold and silver catalysts in the studied process. publishersversion published

The use of nanomaterials is becoming increasingly widespread, leading to substantial research focused on nanomedicine. Nevertheless, the lack of complete toxicity profiles limits nanomaterials’ uses, despite their remarkable diagnostic and therapeutic results on in vitro and in vivo models. Silver nanoparticles (AgNPs), particularly Argovit™, have shown microbicidal, virucidal, and antitumoral effects. Among the first-line toxicity tests is the hemolysis assay. Here, the hemolytic effect of Argovit™ AgNPs on erythrocytes from one healthy donor (HDE) and one diabetic donor (DDE) is evaluated by the hemolysis assay against AgNO3. The results showed that Argovit™, in concentrations ≤24 µg/mL of metallic silver, did not show a hemolytic effect on the HDE or DDE. On the contrary, AgNO3 at the same concentration of silver ions produces more than 10% hemolysis in both the erythrocyte types. In all the experimental conditions assessed, the DDE was shown to be more prone to hemolysis than the HDE elicited by Ag+ ions or AgNPs, but much more evident with Ag+ ions. The results show that Argovit™ is the least hemolytic compared with the other twenty-two AgNP formulations previously reported, probably due to the polymer mass used to stabilize the Argovit™ formulation. The results obtained provide relevant information that contributes to obtaining a comprehensive toxicological profile to design safe and effective AgNP formulations.

SARS-CoV-2 infection in hospital areas is of a particular concern, since the close interaction between health care personnel and patients diagnosed with COVID-19, which allows virus to be easily spread between them and subsequently to their families and communities. Preventing SARS-CoV-2 infection among healthcare personnel is essential to reduce the frequency of infections and outbreaks during the pandemic considering that they work in high-risk areas. In this research, silver nanoparticles (AgNPs) were tested in vitro and shown to have an inhibitory effect on SARS-CoV-2 infection in cultured cells. Subsequently, we assess the effects of mouthwash and nose rinse with ARGOVIT® silver nanoparticles (AgNPs), in the prevention of SARS-CoV-2 contagion in health workers consider as high-risk group of acquiring the infection in the General Tijuana Hospital, Mexico, a hospital for the exclusive recruitment of patients diagnosed with COVID-19. We present a prospective randomized study of 231 participants that was carried out for 9 weeks (during the declaration of a pandemic). The “experimental” group was instructed to do mouthwash and nose rinse with the AgNPs solution; the “control” group was instructed to do mouthwashes and nose rinse in a conventional way. The incidence of SARS-CoV-2 infection was significantly lower in the “experimental” group (two participants of 114, 1.8%) compared to the “control” group (thirty-three participants of 117, 28.2%), with a 84.8% efficiency. We conclude that the mouth and nasal rinse with AgNPs helps in the prevention of SARS-CoV-2 infection in health personnel who are exposed to patients diagnosed with COVID-19.

We investigated the influence of metal loading in gold catalysts supported on titania, either unmodified or La-modified, on their catalytic performance and the formation of active sites for selective oxidation of n-octanol under mild conditions. Catalysts were characterized by BET, EDX, ICP, HRTEM, FTIR CO and XPS. Gold content had a significant effect on the catalytic properties of unmodified catalysts: activity of Au/TiO2 increased by increasing the metal load. However, in the case of a lanthanum-modified support samples, an increase of gold content from 0.5 to 4 wt.% had no effect on its activity (ca. 40% conversion after 6 h for all catalysts). This catalytic behavior is due to a change in the surface concentration of Au+ ions. For the unmodified catalysts, the surface concentration of Au+ ions increased with increasing gold loading, and, as a consequence, a significant increase in activity was observed. For La-modified catalysts, the surface concentration of Au+ ions is almost the same for all gold concentrations; as a result, no increase in activity was observed with the increase in gold content. It points to Au+ ions as the most probable active sites for the studied reaction.

Betulin (90–94%) was extracted from birch with a non-polar solvent and recrystallized from 2-propanol. Liquid-phase oxidation of betulin aimed at obtaining its biologically active oxo-derivatives (betulone, betulonic and betulinic aldehydes), exhibiting e.g. antitumor, anti-inflammatory, antiparasitic, anticancer and anti-HIV properties, was demonstrated for the first time over gold-based catalysts. Gold was deposited on pristine TiO2 and the same support modified with ceria and lanthana, followed by pretreatment with a H2 or O2 atmosphere. The catalysts were characterized by XRD, BET, ICP, TEM, XPS, DRIFT CO, TPD of NH3 and CO2 methods. The nature of the support, type of modification and the pretreatment atmosphere through the metal–support interactions significantly influenced the average particle size of gold, its distribution and the electronic state of gold, as well as the acid–base properties and, thereby, the catalytic performance (activity and selectivity) in betulin oxidation. Au/La2O3/TiO2 pretreated in H2 displayed the highest catalytic activity in betulin oxidation among the studied catalysts with selectivities to betulone, betulonic and betulinic aldehydes of 42, 32 and 27%, respectively, at 69% conversion. Side reactions resulting in oligomerization/polymerization products occurred on the catalyst surface with the participation of strong acid sites, diminishing the yield of the desired compounds. The latter was improved by adding hydrotalcite with the basic properties to the reaction mixture containing the catalyst. Kinetic modelling through numerical data fitting was performed to quantify the impact of such side reactions and determine the values of rate constants.

A novel route to prepare monodispersed 1–2 nm gold nanoparticles (NPs), based on the use of extremely small SiO2 NPs (2–4 nm) as a support and increasing their metal-support interaction with surface modifier oxides is presented. The influence of modifier (La, Ce and Fe oxides) and modification method (impregnation (i) or direct synthesis (s)) on the formation of ultra-small Au NPs and their structural and electronic properties was studied. The samples were characterized by N2 adsorption (BET), FTIR of adsorbed CO, XRD and HR-TEM methods, and tested for the catalytic selective oxidation of 1-octanol. Preparation of monodispersed Au NPs with 1 nm diameter was successfully achieved for all the modified samples studied, with exception of Au/Ce/SiO2-i, where CeO2 was not homogeneously distributed. The Au NPs have high degree of monodispersity and are stable when treated in H2 up to 300 °C. Formation of these Au NPs depended on the strong interactions between the cationic gold complex precursor and the surface of modified SiO2 NPs. Modifiers changed electronic properties of supported gold; favoring the formation and stabilization of Auδ+ states, which are probable gold active sites of selective liquid-phase oxidation of alcohols in redox catalytic processes. 1-octanol oxidation was used as a model reaction for oxidation of fatty alcohols obtained during biomass transformation. The best performance for 1-octanol oxidation was found for gold nanoparticles supported on the ultra-small SiO2 modified cerium oxide by impregnation method. The relative order of activity was: AuCeSiO2-i > AuFeSiO2-i ≫ AuLaSiO2-i ≈ AuLaSiO2-s > AuSiO2 > AuFeSiO2-s≫ AuCeSiO2-s. The obtained results open the possibility of further development of high-performance catalysts for conversion of secondary products of biomass processing into valuable chemicals.

Diabetic foot ulcers are highly susceptible to microbial infections and are the leading cause of lower limb hospitalization and amputation in diabetic patients. Due to their antimicrobial and anti-inflammatory properties, silver nanoparticles (AgNPs) are the most widely used nanomaterial in biomedicine. Herein, we present the usage of AgNPs for the treatment of diabetic foot ulcers with a stage II in Wagner classification. In addition to conventional antibiotic treatment, the ulcers were treated with topical administration of AgNPs at a concentration of 1.2 mg/ml of metallic silver. The results showed a significant improvement in the evolution of the ulcers, where the edges of the lesion were effectively approached, granulation tissue being observed, edema decreased and fibrin plaques. These results form the basis for further studies on the use of AgNPs for the treatment of chronic ulcers of different origins.

Silver nanoparticles (AgNP) are one of the most studied nanoparticles due to their anti-bacterial, -fungal, -viral, -parasitic, and -inflammatory properties. This raises the need to evaluate the toxicity and biological effects of AgNP in the immune system in order to develop new safer biomedical products. In this study, an AgNP formulation currently approved for veterinary applications was applied to mouse bone marrow-derived dendritic cells (BMDC), considered important antigen-presenting cells of the immune system, to evaluate cytotoxicity, genotoxicity, and any significant influence on expression of cellular markers associated with BMDC phenotype and maturation status. The results showed that after 12 h of AgNP exposure, a significant decrease in BMDC viability occurred at the highest concentration tested (1.0 µg AgNP/ml) and at lower doses, the cells maintained membrane integrity and metabolic activity. DNA damage was not significant with any AgNP level aside from the 1.0 µg AgNP/ml level. Regarding phenotype, no differences in expression of CD40 (co-stimulatory molecule highly present in mature BMDC) or in CD273 (a marker for inhibitory T-cell response) were observed. The current results showed that the toxicity of this AgNP formulation was dose-related. The findings also suggest BMDC could maintain structural conservation of co-stimulatory/co-inhibitory surface molecules after 12 h of exposure to this AgNP. This work represents the first step in identifying the toxic effects of this AgNP formulation on dendritic cells.

Influence of modification with metals Au and Ag, oxides of Fe, Mg and Ce and their combinations on amorphization of widely used commercial nanosized TiO2 (Degussa P25) was studied with SR-XRD and EXAFS methods. These systems were chosen taking into account their potential on catalytic properties for biomass to biodiesel transformation, as it was shown in model reaction of liquid phase n-octanol oxidation as well as low-temperature CO oxidation for “cold start” of the neutralizers of car exhaust gases. Instability of rutile, the most stable TiO2 phase, in the presence of the additives was found. Application of EXAFS method, rarely used for crystalline structure transfer studies, led to elucidation of this apparent effect, which was explained by higher level of amorphization of rutile than anatase. Literature data indicate that bulky TiO2 doping leads to either increase of rutile/anatase ratio complete inhibition of anatase to rutile transformation. Dissimilar phase composition changes, revealed in this work for modified nanodispersed TiO2, was attributed to size effect.

Organogenesis and somatic embryogenesis have been widely applied as the two main regeneration pathways in plant tissue cultures. However, recalcitrance is still the main restriction in the clonal propagation of many woody species, especially in conifers. They undergo a “phase change” that leads to significant loss of vegetative propagation capacity, reducing the aptitude of tissues and organs to be regenerated in vitro beyond this point. In line with this, the in vitro regeneration of mature conifer trees has been a long-cherished goal in many laboratories worldwide. Based on previous works in Pinus species regeneration from adult trees, we now present data about the culture of apical shoot buds in an attempt to induce organogenesis and somatic embryogenesis to clone mature trees of Aleppo pine (Pinus halepensis). Reinvigorated axillary shoots were submitted to conditions usually applied to induce somatic embryogenesis through the manipulation of culture media, including the use of auxins such as 2,4-Dichlorophenoxyacetic acid and 1-Naphthaleneacetic acid, cytokinins (6-benzyladenine and kinetin), and phytosulfokine (50, 100, and 200 nM). Although somatic embryos could not be obtained, an embryogenic-like tissue was produced, followed by the emergence of actively proliferating non-embryogenic calli. Variations in the consistence, texture, and color of non-embryogenic calli were observed, especially those arising in the media containing phytosulfokine. Reinvigorated shoots, induced by 22 or 44 µM 6-benzyladenine, were obtained through organogenesis and acclimatized, and phenotypically normal plants were obtained.

Organogenesis and somatic embryogenesis have been widely applied as the two main regeneration pathways in plant tissue cultures. However, recalcitrance is still the main restriction in the clonal propagation of many woody species, especially in conifers. They undergo a “phase change” that leads to significant loss of vegetative propagation capacity, reducing the aptitude of tissues and organs to be regenerated in vitro beyond this point. In line with this, the in vitro regeneration of mature conifer trees has been a long-cherished goal in many laboratories worldwide. Based on previous works in Pinus species regeneration from adult trees, we now present data about the culture of apical shoot buds in an attempt to induce organogenesis and somatic embryogenesis to clone mature trees of Aleppo pine (Pinus halepensis). Reinvigorated axillary shoots were submitted to conditions usually applied to induce somatic embryogenesis through the manipulation of culture media, including the use of auxins such as 2,4-Dichlorophenoxyacetic acid and 1-Naphthaleneacetic acid, cytokinins (6-benzyladenine and kinetin), and phytosulfokine (50, 100, and 200 nM). Although somatic embryos could not be obtained, an embryogenic-like tissue was produced, followed by the emergence of actively proliferating non-embryogenic calli. Variations in the consistence, texture, and color of non-embryogenic calli were observed; especially those arising in the media containing phytosulfokine. Reinvigorated shoots, induced by 22 or 44 µM 6-benzyladenine, were obtained through organogenesis and acclimatized, and phenotypically normal plants were obtained.

Nanomaterials quickly evolve to produce safe and effective biomedical alternatives, mainly silver nanoparticles (AgNPs). The AgNPs&rsquo, antibacterial, antiviral, and antitumor properties convert them into a recurrent scaffold to produce new treatment options. This work reported the full characterization of a highly biocompatible protein-coated AgNPs formulation and their selective antitumor and amoebicidal activity. The protein-coated AgNPs formulation exhibits a half-inhibitory concentration (IC50) = 19.7 &micro, M (2.3 &micro, g/mL) that is almost 10 times more potent than carboplatin (first-line chemotherapeutic agent) to inhibit the proliferation of the highly aggressive human adenocarcinoma HCT-15. The main death pathway elicited by AgNPs on HCT-15 is apoptosis, which is probably stimulated by reactive oxygen species (ROS) overproduction on mitochondria. A concentration of 111 &micro, M (600 &micro, g/mL) of metallic silver contained in AgNPs produces neither cytotoxic nor genotoxic damage on human peripheral blood lymphocytes. Thus, the AgNPs formulation evaluated in this work improves both the antiproliferative potency on HCT-15 cultures and cytotoxic selectivity ten times more than carboplatin. A similar mechanism is suggested for the antiproliferative activity observed on HM1-IMSS trophozoites (IC50 = 69.2 &micro, M, 7.4 &micro, g/mL). There is no change in cell viability on mice primary cultures of brain, liver, spleen, and kidney exposed to an AgNPs concentration range from 5.5 &micro, M to 5.5 mM (0.6 to 600 &micro, g/mL). The lethal dose was determined following the OECD guideline 420 for Acute Oral Toxicity Assay, obtaining an LD50 = 2618 mg of Ag/Kg body weight. All mice survived the observational period, the histopathology and biochemical analysis show no differences compared with the negative control group. In summary, all results from toxicological evaluation suggest a Category 5 (practically nontoxic) of the Globally Harmonized System of Classification and Labelling of Chemicals for that protein-coated AgNPs after oral administration for a short period and urge the completion of its preclinical toxicological profile. These findings open new opportunities in the development of selective, safe, and effective AgNPs formulations for the treatment of cancer and parasitic diseases with a significant reduction of side effects.

Nanotechnology has become a research area with promising results for technological innovation. Endodontics can benefit from this field of research by increasing the success rate of the treatment, which currently ranges between 86% and 98% and has varied very little over the years. One of the causes of endodontic treatment failure is based on the presence of Enterococcus faecalis. The objective of this investigation is to evaluate the antibacterial effect of a gel preparation containing silver nanoparticles (Ag-NP) against E. faecalis present in the walls of the root canal. 60 extracted human uniradicular teeth that were instrumented with Wave One Gold (Denstplay/USA) and subsequently contaminated with Enterococcus faecalis. For antibacterial evaluation, intra-canal conducting was placed, and several groups were formed: a) Ag-NP 300 ug/MI gel; b) Ag-NP 500 ug/MI gel; c) Ca (OH) 2 (Ultracal from Ultradent/USA) and the control group. They were incubated at 37°C and a sample was taken every 24 h for 7 days. The Ag-NP gel showed antimicrobial activity against E. faecalis with a value of minimum inhibitory concentration and minimum bactericidal concentration of 300 g/ml and 900 g/ml, respectively. When the Ag-NP gel was used as an intra-canal conducting drug in an in-vitro model, its antimicrobial effect at 300 g/ml and 500 g/ml was equivalent to the action of Ca(OH)2.

Psidium friedrichsthalianum (O. Berg) Nied. (Cas) is a guava species from Myrtaceae family whose fruits are very attractive for their organoleptic properties, its economic and nutritional importance and its use as rootstocks. One of the main problems for in vitro propagation of Cas is contamination, and silver nanoparticles (AgNPs), are the most useful in the treatment of plant tissues due to their microbicidal action. Thus, the microbicidal effect of Argovit™ AgNPs (suspension in water, with PVP 18.8 wt% and metallic silver 1.2 wt%, in spheroids form of 35 ± 15 nm, hydrodynamic diameter of 70 nm and zeta potential of − 15 mV) was evaluated either, through the disinfection of Cas shoot tips explants or by dispensing a liquid layer of AgNPs onto the semisolid culture medium during the in vitro establishment phase. The effect of Argovit™ silver nanoparticles in the multiplication rate and the foliar area of Cas was also evaluated. Application of AgNPs 50 mg/L directly to shoot tips during 5 min yielded a contamination rate of 40%, while culture medium sterilization with 5 mg/L of AgNPs as a permanent bilayer reduced shoot contamination rate to 50% compared to 80% for the controls. In addition, Argovit™ silver nanoparticles also enhanced foliar area by 560% (from 0.073 to 0.409 cm2) and multiplication rate by 180% (from 1.286 to 2.286 shoots/explant). The study concluded that the best way for in vitro use of AgNPs on propagation of P. friedrichsthalianum, is as sterilization agent of the culture media because produce additional advantage of enhancing the leaf area and multiplication rate of the shoots.

Due to their antibacterial and antiviral effects, silver nanoparticles (AgNP) are one of the most widely used nanomaterials worldwide in various industries, e.g., in textiles, cosmetics and biomedical-related products. Unfortunately, the lack of complete physicochemical characterization and the variety of models used to evaluate its cytotoxic/genotoxic effect make comparison and decision-making regarding their safe use difficult. In this work, we present a systematic study of the cytotoxic and genotoxic activity of the commercially available AgNPs formulation Argovit&trade, in Allium cepa. The evaluated concentration range, 5&ndash, 100 &micro, g/mL of metallic silver content (85&ndash, 1666 &micro, g/mL of complete formulation), is 10&ndash, 17 times higher than the used for other previously reported polyvinylpyrrolidone (PVP)-AgNP formulations and showed no cytotoxic or genotoxic damage in Allium cepa. Conversely, low concentrations (5 and 10 &micro, g/mL) promote growth without damage to roots or bulbs. Until this work, all the formulations of PVP-AgNP evaluated in Allium cepa regardless of their size, concentration, or the exposure time had shown phytotoxicity. The biological response observed in Allium cepa exposed to Argovit&trade, is caused by nanoparticles and not by silver ions. The metal/coating agent ratio plays a fundamental role in this response and must be considered within the key physicochemical parameters for the design and manufacture of safer nanomaterials.

In this study, the antifungal activity of AgNPs was tested against C. tropicalis (pathogen fungi) and S. boulardii (probiotic). The effectiveness of the AgNPs was assessed by comparing their antifungal activity with a triazole antifungal drug fluconazole and amphotericin B. The AgNPs have a polygonal-like shape (average size of 35 ± 15 nm) with 1.2% wt. of metallic silver stabilized with 18.8% wt. of polyvinylpyrrolidone (PVP) in 80% wt. of distilled water. The results revealed that 35 μg/mL of fluconazole inhibits 55–60% of both fungal cell growth. As for amphotericin B, 5 μg/mL is sufficient to inhibit more than 95% of both fungal cells. For AgNPs, 25 μg/mL was needed to inhibit 90% of the C. tropicalis cell growth, but remarkably, 50% of the S. boulardii cell population remains viable, which can potentiate cell reproduction. Our results could initiate the development of AgNPs possessing selective specificity against pathogenic fungal species.

Skin burns and ulcers are considered hard-to-heal wounds due to their high infection risk. For this reason, designing new options for wound dressings is a growing need. The objective of this work is to investigate the properties of poly (&epsilon, caprolactone)/poly (vinyl-pyrrolidone) (PCL/PVP) microfibers produced via electrospinning along with sorbents loaded with Argovit&trade, silver nanoparticles (Ag-Si/Al2O3) as constituent components for composite wound dressings. The physicochemical properties of the fibers and sorbents were characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and inductively coupled plasma optical emission spectroscopy (ICP-OES). The mechanical properties of the fibers were also evaluated. The results of this work showed that the tested fibrous scaffolds have melting temperatures suitable for wound dressings design (58&ndash, 60 &deg, C). In addition, they demonstrated to be stable even after seven days in physiological solution, showing no macroscopic damage due to PVP release at the microscopic scale. Pelletized sorbents with the higher particle size demonstrated to have the best water uptake capabilities. Both, fibers and sorbents showed antimicrobial activity against Gram-negative bacteria Pseudomona aeruginosa and Escherichia coli, Gram-positive Staphylococcus aureus and the fungus Candida albicans. The best physicochemical properties were obtained with a scaffold produced with a PCL/PVP ratio of 85:15, this polymeric scaffold demonstrated the most antimicrobial activity without affecting the cell viability of human fibroblast. Pelletized Ag/Si-Al2O3-3 sorbent possessed the best water uptake capability and the higher antimicrobial activity, over time between all the sorbents tested. The combination of PCL/PVP 85:15 microfibers with the chosen Ag/Si-Al2O3-3 sorbent will be used in the following work for creation of wound dressings possessing exudate retention, biocompatibility and antimicrobial activity.

The objective of this study was to evaluate the histopathological alterations in juvenile Penaeus vannamei caused by silver nanoparticles (AgNPs) for two types of experiments: at sublethal concentrations of 3.6 to 7.1 μg/μL of metallic silver (Ag) for a short period up to 72 h and for 2.6 to 7.9 μg of Ag/μL for the long period up to 264 h. The severity degree of the changes was evaluated and the histopathological index (Hi) was determined in both experiments using the necrosis (cellular dead) as an indicator. The pathological changes in the striated muscle, gills, antennal gland, circulatory system, heart, lymphoid organ, and connective tissue are described. The histopathological effects were similar for the two experiments without a direct relationship with the concentrations. In the short-term experiment, the values of Hi were higher (2.34 ± 0.41 at 48 hpi and 1.91 ± 0.39 at 72 hpi) compared with the long-term experiment (values between 0.57 ± 0.36 to 1.74 ± 0.57 at 264 hpi). The observed pathologies are similar to those caused by other metals, with the exception of the agglomerations of black particles in the gills, lymphoid organ, and muscle, which has not been previously reported. This work shows that silver nanoparticles cause damage to shrimp in sublethal concentrations.

In this study, four experimental assays were conducted to evaluate the use of a new silver nanoparticle formulation named Argovit-4, which was prepared with slight modifications to enhance its biological activity against white spot syndrome virus (WSSV) in shrimp culture. The goals of these assays were to (1) determine the protective effect of Argovit-4 against WSSV, (2) determine whether Argovit-4 supplemented in feed exhibits toxicity towards shrimp, (3) determine whether Argovit-4 as antiviral additive in feed can prevent or delay/reduce WSSV-induced shrimp mortality, and (4) determine whether Argovit-4 supplemented in feed alters the early stages of the shrimp immune response. In bioassay 1, several viral inocula calibrated at 7 SID50(shrimp infectious doses 50% endpoint) were exposed to 40, 100, 200 and 1,000 ng/SID50of Ag+and then intramuscularly injected into shrimp for 96 h. In bioassay 2, shrimp were fed Argovit-4 supplemented in feed at different concentrations (10, 100 and 1,000 µg per gram of feed) for 192 h. In bioassay 3, shrimp were treated with Argovit-4 supplemented in feed at different concentrations and then challenged against WSSV for 192 h. In bioassay 4, quantitative real-time RT-qPCR was performed to measure the transcriptional responses of five immune-relevant genes in haemocytes of experimental shrimp treated with Argovit-4 supplemented in feed at 0, 6, 12, 24 and 48 h. The intramuscularly injected Argovit-4 showed a dose-dependent effect (p

The efficiency of Au/TiO2 based catalysts in 1-phenylethanol oxidation was investigated. The role of support modifiers (La2O3 or CeO2), influence of gold loading (0.5% or 4%) and redox pretreatment atmosphere, catalyst recyclability, effect of oxidant: tert-butyl hydroperoxide (TBHP) or O2, as well as the optimization of experimental parameters of the reaction conditions in the oxidation of this alcohol were studied and compared with previous studies on 1-octanol oxidation. Samples were characterized by temperature-programmed oxygen desorption (O2-TPD) method. X-ray photoelectron spectroscopy (XPS) measurements were carried out for used catalysts to find out the reason for deactivation in 1-phenylethanol oxidation. The best catalytic characteristics were shown by catalysts modified with La2O3, regardless of the alcohol and the type of oxidant. When O2 was used, the catalysts with 0.5% Au, after oxidative pretreatment, showed the highest activity in both reactions. The most active catalysts in 1-phenylethanol oxidation with TBHP were those with 4% Au and the H2 treatment, while under the same reaction conditions, 0.5% Au and O2 treatment were beneficial in 1-octanol oxidation. Despite the different chemical nature of the substrates, it seems likely that Au+(Au&delta, +) act as the active sites in both oxidative reactions. Density functional theory (DFT) simulations confirmed that the gold cationic sites play an essential role in 1-phenylethanol adsorption.

Silver nanoparticles (AgNPs) are the most used nanomaterials worldwide due to their excellent antibacterial, antiviral, and antitumor activities, among others. However, there is scarce information regarding their genotoxic potential measured using human peripheral blood lymphocytes. In this work, we present the cytotoxic and genotoxic behavior of two commercially available poly(vinylpyrrolidone)-coated silver nanoparticle (PVP-AgNPs) formulations that can be identified as noncytotoxic and nongenotoxic by just evaluating micronuclei (MNi) induction and the mitotic index, but present enormous differences when other parameters such as cytostasis, apoptosis, necrosis, and nuclear damage (nuclear buds (NBUDs) and nucleoplasmic bridges (NPBs)) are analyzed. The results show that Argovit (35 nm PVP-AgNPs) and nanoComposix (50 nm PVP-AgNPs), at concentrations from 0.012 to 12 μg/mL, produce no changes in the nuclear division index (NDI) or micronuclei (MNi) frequency compared with the values found on control cultures of human blood peripheral lymphocytes from a healthy donor. Still, 50 nm PVP-AgNPs significantly decrease the replication index and significantly increase cytostasis, apoptosis, necrosis, and the frequencies of nuclear buds (NBUDs) and nucleoplasmic bridges (NPBs). These results provide evidence that the cytokinesis-block micronucleus (CBMN) assay using human lymphocytes and evaluating the eight parameters provided by the technique is a sensitive, fast, accurate, and inexpensive detection tool to support or discard AgNPs or other nanomaterials, which is worthwhile for continued testing of their effectiveness and toxicity for biomedical applications. In addition, it provides very important information about the role played by the [coating agent]/[metal] ratio in the design of nanomaterials that could reduce adverse effects as much as possible while retaining their therapeutic capabilities.

© 2020 by the authors., Gold nanoparticles supported on various oxides (CeO2, CeO2/TiO2, MgO, MgO/TiO2, La2O3, La2O3/TiO2) (with 4 wt.% Au loading) were investigated in the liquid (aqueous) phase oxidation of glycerol by molecular oxygen under mild conditions, in the presence of alkaline earth (CaO, SrO and MgO) or alkaline (NaOH) bases. Full conversion and selectivity between 38 and 68% to sodium glycerate were observed on different Au supported catalysts (Au/MgO/TiO2, Au/La2O3/TiO2, Au/CeO2 and Au/CeO2/TiO2). The combined effect of Au particle size and basicity of the support was suggested as the determining factor of the activity. Agglomeration of gold nanoparticles, found after the reaction, led to the deactivation of the catalysts, which prevents the further oxidation of sodium glycerate into sodium tartronate. Promising results were obtained with the use of alkaline earth bases (CaO, SrO, MgO), leading to the formation of free carboxylic acids instead of salts, which are formed in the presence of the more usual base, NaOH., This work was partially supported by the Associate Laboratory for Green Chemistry (LAQV), financed by national funds from FCT/MCTES (UIDB/50006/2020) (Portugal), the Tomsk Polytechnic University Competitiveness Enhancement Program project VIU-RSCBMT-197/2020, and the Russian Foundation of Basic Research, project 18-29-24037.

El estudio de la genotoxicidad en modelos murinos es útil para responder las dudas relacionadas con la seguridad por el uso de nanomateriales, sobre todo cuando se pretende el desarrollo de nuevas opciones terapéuticas. El propósito de este trabajo fue evaluar la capacidad genotóxica de AgNPs Argovit™ a partir de la técnica de micronúcleos en reticulocitos de sangre periférica de ratones, prueba ampliamente utilizada para conocer el potencial genotóxico de diferentes agentes. Las nanopartículas de plata se suministraron en dosis terapéuticas por vía oral (indicadas para perros como tratamiento para el moquillo) durante tres días a un grupo conformado por siete ratones y a otros dos grupos con igual número de ratones se administró respectivamente agua inyectable y arabinosa C. Los especímenes fueron medidos, pesados antes y después del experimento. También se tomaron diariamente muestras de sangre periférica mediante un corte en la punta de la cola para posteriormente realizar extendidos sobre portaobjetos para la prueba de micronúcleos en reticulocitos. Los frotis se fijaron en etanol al 80 % y se tiñeron con anaranjado de acridina para posteriormente leer en 1000 reticulocitos la presencia de micronúcleos con microscopio de fluorescencia. Los resultados preliminares muestran diferencias significativas en el número de micronúcleos en reticulocitos entre los tres grupos, por lo que se requiere comprobar este resultado con otro tipo de modelos in vitro.

The purpose of this work was to evaluate the genotoxic capacity of AgNPs Argovit™ with the micronucleus technique in mouse peripheral blood reticulocytes. Argovit™ is administered orally in therapeutic doses (indicated for dogs as treatment for distemper) for three days to an experimental group with seven mice. Another two groups with an equal number of mice were administered with injectable water and arabinose C, respectively. The specimens were measured and weighed before and after the experiment. Peripheral blood samples were also taken daily by a cut at the tip of the tail and then extended on slides for micronucleus test in reticulocytes. The smears were fixed in ethanol at 80 % and stained with acridine orange, after that, the presence of micronuclei was identified in 1000 reticulocytes counted by fluorescence microscopy. Preliminary results show significant differences in the number of micronuclei in reticulocytes between the three groups, so it’s necessary to compare this result with another type of in vitro models.

This study aims to improve gold-based catalyst effectiveness in n-octanol oxidation by adjusting the structural and electronic properties of gold through incorporation of additives to support. Au/La/TiO2, Au/Ce/TiO2, and Au/TiO2 catalysts, prepared by deposition-precipitation with urea, were tested in the base-free oxidation of octanol under mild conditions in liquid phase. The influence of additives on structural properties of the catalyst and the active phase, and on the electronic and redox properties of the active gold species was studied by TEM, SR-XRD, EXAFS, FTIR of adsorbed CO, and XPS. Support modifiers affected gold particle size distribution, but no direct dependence of the catalyst activity on Au NPs average size was observed. The activity of as-prepared catalysts was limited, and even lower in the presence of modifiers at that stage. Reductive pretreatment boosted the activity of every catalyst, and support modification with La and Ce increased four- and two-fold, respectively, the activity of Au/TiO2 under the same reaction conditions. The nature of modifiers also affected the product distribution where the outstanding performance of Au/La/TiO2 gives rise to the highest ester selectivity at isoconversion with no acid formation. Overall, the studied catalysts, and especially Au/Ce/TiO2, and Au/La/TiO2, hold promise for n-octanol oxidation under mild conditions.

White spot syndrome virus (WSSV) is highly lethal and contagious in shrimps; its outbreaks causes an economic crisis for aquaculture. Several attempts have been made to treat this disease; however, to date, there is no effective cure. Because of their antimicrobial activities, silver nanoparticles (AgNPs) are the most studied nanomaterial. Although the antiviral properties of AgNPs have been studied, their antiviral effect against viral infection in aquaculture has not been reported. The AgNPs tested herein are coated with polyvinylpyrrolidone (PVP) and possess multiple international certifications for their use in veterinary and human applications. The aim of this work was to evaluate the survival rate of juvenile white shrimps (Litopenaeus vannamei) after the intramuscular administration of AgNPs. For this, different concentrations of metallic AgNPs and PVP alone were injected into the organisms. After 96 h of administration, shrimp survival was more than 90% for all treatments. The oxygen consumption routine rate and total hemocyte count remained unaltered after AgNP injection, reflecting no stress caused. We evaluated whether AgNPs had an antiviral effect in shrimps infected with WSSV. The results revealed that the survival rate of WSSV-infected shrimps after AgNP administration was 80%, whereas the survival rate of untreated organisms was only 10% 96 h after infection. These results open up the possibility to explore the potential use of AgNPs as antiviral agents for the treatment of diseases in aquaculture organisms, particularly the WSSV in shrimp culture.

This work aims to further the understanding of gold-based catalytic oxidation of n-octanol in liquid phase. Modification of catalysts with metal oxides additives (Fe or Mg) was used as a tool for transforming and stabilizing gold species. Structural, electronic and catalytic properties of gold catalysts were systematically investigated by means of DRS, H2, CO FTIR, SBET, EDS and SEM, HRTEM, SR-XRD, XANES, XPS and liquid phase n-octanol oxidation. Addition of modifiers affects Au electronic properties, but not the structural ones. Characterization results allow excluding Au3+ ions as candidates for active sites in n-octanol oxidation. In Au/Mg/TiO2, gold exhibited more reduced states while in Au/Fe/TiO2 gold was more oxidized; Au/TiO2 for intermediate oxidized states was found. The proper balance of oxidation states in the gold surface of Au/Mg/TiO2 can be responsible for its higher activity compared with Au/Fe/TiO2 and Au/TiO2 towards n-octanol oxidation. Finally our approach shed light on the nature of active sites for n-octanol oxidation on gold and furthers the development of green base-free catalytic oxidation of alcohols.

The wide application of silver nanoparticles (AgNPs) has pointed out the need to evaluate their potential risk and toxic effects on human health. Herein, the cytotoxic effects of Argovit™ AgNPs were evaluated on eight cancer cell lines. Further cytotoxic studies were performed in gynecological cancer cell lines from cervical (HeLa) and breast (MDA-MB-231 and MCF7) cancer. In both cases, the half maximal inhibitory concentration (IC50) of AgNPs produced the formation of reactive oxygen species (ROS) after 24 h of incubation, but it was not statistically significant compared with untreated cells. However, HeLa, MDA-MB-231, and MCF7 cells treated with the maximal IC of AgNPs induced the formation of ROS either at 12 or 24 h of incubation. Genotoxicity achieved by comet assay in HeLa, MDA-MB-231, and MCF7 cells revealed that exposure to IC50 of AgNPs does not induced noticeable DNA damage in the cells. However, the IC of AgNPs provoked severe DNA damage after 12 and 24 h of exposure. We conclude that, Argovit (polyvinylpyrrolidone-coated AgNPs) induce a cytotoxic effect in a time and dose-dependent manner in all the eight cancer cell lines tested. Nevertheless, the genotoxic effect is mainly restricted by the concentration effect. The results contribute to explore new therapeutic applications of AgNPs for malignances in murine models and to study in deep the cytotoxic and genotoxic effects of AgNPs in healthy cells at the surrounding tissue of the neoplasia.

During the last 3 decades, there has been a slow advance to obtain new treatments for malignant melanoma that improve patient survival. In this work, we present a systematic study focused on the antiproliferative and antitumour effect of AgNPs. These nanoparticles are fully characterized, are coated with polyvinylpyrrolidone (PVP), and have an average size of 35±15 nm and a metallic silver content of 1.2% wt. Main changes on cell viability, induction of apoptosis and necrosis, and ROS generation were found on B16-F10 cells after six hours of exposure to AgNPs (IC50=4.2 μg/mL) or Cisplatin (IC50=2.0 μg/mL). Despite the similar response for both AgNPs and Cisplatin on antiproliferative potency (cellular viability of 53.95±1.88 and 53.62±1.04) and ROS production (20.27±1.09% and 19.50±0.35%), significantly different cell death pathways were triggered. While AgNPs induce only apoptosis (45.98±1.88%), Cisplatin induces apoptosis and necrosis at the same rate (22.31±1.72% and 24.07±1.10%, respectively). In addition to their antiproliferative activity, in vivo experiments showed that treatments of 3, 6, and 12 mg/kg of AgNPs elicit a survival rate almost 4 times higher (P<0.05) compared with the survival rate obtained with Cisplatin (2 mg/kg). Furthermore, the survivor mice treated with AgNPs do not show genotoxic damage determined by micronuclei frequency quantification on peripheral blood cells. These results exhibit the remarkable antitumour activity of a nongenotoxic AgNP formulation and constitute the first advance toward the application of these AgNPs for melanoma treatment, which could considerably reduce adverse effects provoked by currently applied chemotherapeutics.

[EN] Reductive amination of cyclohexanone with benzylamine was investigated at 100 °C under 30 bar hydrogen in toluene with five different gold catalysts prepared by deposition–precipitation method and supported on TiO, LaO/TiO, CeO/TiO, LaO and CeO. Size of metallic gold varied in the range of 2.6–3.6 nm. The best catalysts in reductive amination of cyclohexanone with benzylamine were 4 wt% Au/TiO and 4 wt% Au/CeO/TiO giving 72% and 79% yield of the desired amine. The most acidic and basic catalysts were also unselective and exhibited low activity towards imine hydrogenation. The best catalyst 4 wt% Au/CeO/TiO gave in reductive amination of propiophenone 56% selectivity to the corresponding amine at 20% conversion in 5 h. Graphical Abstract: [Figure not available: see fulltext.], Open access funding provided by Abo Akademi University (ABO). The research is funded from Tomsk Polytechnic University Competitiveness Enhancement Program project VIU-RSCBMT-65/2019.

Digitalization determines the development of all processes in the economic and public areas, including the issue of strengthening economic security. The article discusses the problem of digitalization of one of the types of economic activity of the region. The relationship between the development of agriculture and economic security of the region is presented. The authors identify the degree of damage and threshold values in the estimation of the economic security of the region and approbate the original method in the Sverdlovsk region. The article discusses the aspects of the existing level of economic security of the Sverdlovsk region and identifies the problems. The paper provides recommendations for solving these problems and makes calculations of benefits from the introduction of certain Russian digital technologies into operation.

New silver containing sorbents, based on mineral carriers, such as alumina and silica systems with a meso- and macro- porous structure, have a higher mechanical resistance and, hydrophilic and hydrophobic chemical composition of the surface. These sorbents are easy to find and relatively inexpensive, compared to their known equivalents. They are furthermore characterised by high specific surface and simple preparation, whilst the addition of silver considerably increases their antiseptic activity. The results of research of the physical, chemical and biological properties of the developed substances, as well as bio-comparability of sorbents with biological tissues, are presented in this paper. The modified material acts simultaneously as the carrier for active substances to the area of therapeutic application and as a sorbent used to remove toxic agents from such areas. This approach led us to modify the sorbent, and prolong the delivery of substances such as silver, as an effective antibacterial and antimycotic agent.

New silver containing sorbents, based on mineral carriers, such as alumina and silica systems with a meso- and macro- porous structure, have a higher mechanical resistance and, hydrophilic and hydrophobic chemical composition of the surface. These sorbents are easy to find and relatively inexpensive, compared to their known equivalents. They are furthermore characterised by high specific surface and simple preparation, whilst the addition of silver considerably increases their antiseptic activity. The results of research of the physical, chemical and biological properties of the developed substances, as well as bio-comparability of sorbents with biological tissues, are presented in this paper. The modified material acts simultaneously as the carrier for active substances to the area of therapeutic application and as a sorbent used to remove toxic agents from such areas. This approach led us to modify the sorbent, and prolong the delivery of substances such as silver, as an effective antibacterial and antimycotic agent.

Mesoporous silica composed by small nanoparticles has been synthesized by a modified neutral S 0 I 0 templating route method (S 0 , neutral primary amine surfactant; I 0 , neutral inorganic precursor). Decreasing the polarity of the medium and tuning the composition of the S 0 I 0 pair allow the formation of silica nanoparticles that are agglomerated into silica fractal or sponge-like structures. Those nanoparticles conform the building blocks of the neutral S 0 I 0 method. In this work for the first time they are observed isolated by HRTEM. On the other hand, the addition of metal oxides triggers the formation of aggregates containing unusually small silica nanoparticles, i.e. smaller building blocks that in bare silica, in the range of 2–4 nm. Further, through the impregnation of a gold precursor post-synthesis, ultra small gold nanoparticles (1 nm) were embedded in the final silica nanostructures upon calcination of the organic precursors. FTIR and UV–vis spectroscopies, TEM and SEM, XRD and N 2 absorption were used to characterize the resultant materials.