Nanoparticles Partially Restore Bacterial Susceptibility to Antibiotics.

The growing resistance of bacteria to antibiotics is one of the main public health problems nowadays. The influence of silver nanoparticle (AgNP) pretreatment of 220 cows with mastitis on the susceptibility of Staphylococcus epidermidis bacteria to 31 antibiotics was studied. The obtained results were compared with the previous results for Escherichia coli, Streptococcus dysgalactiae, and Staphylococcus aureus. For all four bacteria, an increase in susceptibility (9.5-21.2%) to 31 antibiotics after cow treatment with AgNPs was revealed, while after first-line antibiotic drug treatment as expected, the susceptibility decreased (11.3-27.3%). These effects were explained by (1) the increase in the contribution of isolates with efflux effect after antibiotic treatments and its decrease after AgNP treatment and (2) the changes in bacteria adhesion and anti-lysozyme activity after these treatments. The effect of the increasing antibacterial activity of antibiotics after AgNP treatment was the most pronounced in the case of E. coli and was minimal in the case of S. epidermidis. With AgNP treatment, the time of recovery decreased by 26.8-48.4% compared to the time of recovery after treatment with the first-line antibiotic drugs. The AgNP treatment allows for achieving the partial restoration of the activity of antibiotics.

Revealing the Second and the Third Causes of AgNPs Property to Restore the Bacterial Susceptibility to Antibiotics.

The increase in bacterial resistance to antibiotics is a global problem for public health. In our previous works, it was shown that the application of AgNPs in cow mastitis treatment increased S. aureus and S. dysgalactiae susceptibility to 31 antibiotics due to a decrease in the bacterial efflux effect. The aim of the present work was to shed light on whether the change in adhesive and anti-lysozyme activities caused by AgNPs also contribute to the restoration of bacterial susceptibility to antibiotics. In vivo sampling was performed before and after cow mastitis treatments with antibiotics or AgNPs. The isolates were identified, and the adhesive and anti-lysozyme activities were assessed. These data were compared with the results obtained for in vitro pre-treatment of reference bacteria with AgNPs or antibiotics. The present study revealed that bacterial treatments in vitro and in vivo with AgNPs: (1) decrease the bacterial ability to adhere to cells to start an infection and (2) decrease bacterial anti-lysozyme activity, thereby enhancing the activity of lysozyme, a natural "antibiotic" present in living organisms. The obtained data contribute to the perspective of the future application of AgNPs for recovering the activity of antibiotics rapidly disappearing from the market.

The Effect of Silver Nanoparticle Addition on Micropropagation of Apricot Cultivars (Prunus armeniaca L.) in Semisolid and Liquid Media.

Silver nanoparticles (AgNPs) are novel compounds used as antimicrobial and antiviral agents. In addition, AgNPs have been used to improve the growth of different plants, as well as the in vitro multiplication of plant material. In this work the effect of AgNPs on in vitro growth of 'Canino' and 'Mirlo Rojo' cultivars, as well as the leaf ion composition, are studied. Different concentrations of AgNPs (0, 25, 50, 75 and 100 mg L-1) were added to two culture systems: semisolid medium with agar (SSM) in jars and liquid medium in temporary immersion system (TIS). Proliferation (number of shoots), shoot length, productivity (number of shoot × average length), leaf surface, fresh and dry weight were measured. Additionally, the silver and other ion accumulation in the leaves were evaluated by inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis. The productivity of 'Canino' and 'Mirlo Rojo' decreased when increasing the concentration of AgNPs in the semisolid medium. However, the use of AgNPs in the TIS improved the proliferation and productivity of 'Canino' and Mirlo Rojo', increasing biomass production, and the concentration of nutrients in the plants, although these effects are genotype-dependent. TISs are the best system for introducing silver into shoots, the optimum concentration being 50 mg L-1 for 'Canino' and 75 mg L-1 for 'Mirlo Rojo'. Principal component analysis, considering all the analyzed ions along the treatments, separates samples in two clear groups related to the culture system used. The use of bioreactors with a liquid medium has improved the productivity of 'Canino' and 'Mirlo Rojo' in the proliferation stage, avoiding hyperhydration and other disorders. The amount of metallic silver that penetrates apricot plant tissues depends on the culture system, cultivar and concentration of AgNPs added to the culture medium. Silver ion accumulation measured in the shoots grown in the TIS was higher than in shoots micropropagated in a semisolid medium, where it is barely detectable. Furthermore, AgNPs had a beneficial effect on plants grown in TIS. However, AgNPs had a detrimental effect when added to a semisolid medium.

Solution of the Drug Resistance Problem of Escherichia coli with Silver Nanoparticles: Efflux Effect and Susceptibility to 31 Antibiotics.

The current work is a continuation of our studies focused on the application of nanoparticles of metallic silver (AgNPs) to address the global problem of antibiotic resistance. In vivo, fieldwork was carried out with 200 breeding cows with serous mastitis. Ex vivo analyses showed that after the cow was treated with an antibiotic-containing drug DienomastTM, E. coli sensibility to 31 antibiotics decreased by 27.3%, but after treatment with AgNPs, it increased by 21.2%. This could be explained by the 8.9% increase in the portion of isolates showing an efflux effect after DienomastTM treatment, while treatment with Argovit-CTM resulted in a 16.0% drop. We verified the likeness of these results with our previous ones on S. aureus and Str. dysgalactiae isolates from mastitis cows processed with antibiotic-containing medicines and Argovit-CTM AgNPs. The obtained results contribute to the recent struggle to restore the efficiency of antibiotics and to preserve the wide range of antibiotics on the world market.

A Comparative Study of Cancer Cells Susceptibility to Silver Nanoparticles Produced by Electron Beam.

INTRODUCTION: Silver nanoparticles (AgNPs) have a wide range of bioactivity, which is highly dependent on particle size, shape, stabilizer, and production method. Here, we present the results of studies of AgNPs cytotoxic properties obtained by irradiation treatment of silver nitrate solution and various stabilizers by accelerating electron beam in a liquid medium. METHODS: The results of studies of morphological characteristics of silver nanoparticles were obtained by transmission electron microscopy, UV-vis spectroscopy, and dynamic light scattering measurements. MTT test, alamar blue test, flow cytometry, and fluorescence microscopy were used to study the anti-cancer properties. As biological objects for standard tests, adhesive and suspension cell cultures of normal and tumor origin, including prostate cancer, ovarian cancer, breast cancer, colon cancer, neuroblastoma, and leukemia, were studied. RESULTS: The results showed that the silver nanoparticles obtained by irradiation with polyvinylpyrrolidone and collagen hydrolysate are stable in solutions. Samples with different stabilizers were characterized by a wide average size distribution from 2 to 50 nm and low zeta potential from -7.3 to +12.4 mV. All AgNPs formulations showed a dose-dependent cytotoxic effect on tumor cells. It has been established that the particles obtained with the combination of polyvinylpyrrolidone/collagen hydrolysate have a relatively more pronounced cytotoxic effect in comparison to samples stabilized with only collagen or only polyvinylpyrrolidone. The minimum inhibitory concentrations for nanoparticles were less than 1 µg/mL for various types of tumor cells. It was found that neuroblastoma (SH-SY5Y) is the most susceptible, and ovarian cancer (SKOV-3) is the most resistant to the action of silver nanoparticles. The activity of the AgNPs formulation prepared with a mixture of PVP and PH studied in this work was higher that activity of other AgNPs formulations reported in the literature by about 50 times. CONCLUSIONS: The results indicate that the AgNPs formulations synthesized with an electron beam and stabilized with polyvinylpyrrolidone and protein hydrolysate deserve deep study for their further use in selective cancer treatment without harming healthy cells in the patient organism.

Silver nanoparticles induce a non-immunogenic tumor cell death.

Immunogenic cell death (ICD) is a form of cell death characterized by the release of danger signals required to trigger an adaptive immune response against tumor-associated antigens. Silver nanoparticles (AgNP) display anti-proliferative and cytotoxic effects in tumor cells, but it has not been previously studied whether AgNP act as an ICD inductor. The present study evaluated the in vitro release of calreticulin as a damage-associated molecular pattern (DAMP) associated with the cytotoxicity of AgNP and their in vivo anti-cancer effects. In vitro, mouse CT26 colon carcinoma and MCA205 fibrosarcoma cells were exposed to AgNP and then cell proliferation, adhesion, and release of calreticulin were determined. The results indicated there were time- and concentration-related anti-proliferative effects of AgNP in both the CT26 and MCA205 lines. Concurrently, changes in cell adhesion were detected mainly in the CT26 cells. Regarding DAMP detection, a significant increase in calreticulin was observed only in CT26 cells treated with doxorubicin and AgNP; however, no differences were found in the MCA205 cells. In vivo, the survival and growth of subcutaneous tumors were monitored after vaccination of mice with cell debris from tumor cells treated with AgNP or after intra-tumoral administration of AgNP to established tumors. Consequently, anti-tumoral prophylactic immunization with AgNP-dead cells failed to protect mice from tumor re-challenge; intra-tumor injection of AgNP did not induce a significant effect. In conclusion, there was a noticeable anti-tumoral effect of AgNP in vitro in both CT26 and MCA205 cell lines, accompanied by the release of calreticulin in CT26 cells. In vivo, immunization with cell debris derived from AgNP-treated tumor cells failed to induce a protective immune response in the cancer model mice. Clearly, further research is needed to determine if one could combine AgNP with other ICD inducers to improve the anti-tumor effect of these nanoparticles in vivo.

Chronic toxicity of shrimp feed added with silver nanoparticles (Argovit-4®) in Litopenaeus vannamei and immune response to white spot syndrome virus infection.

In recent years, the application of silver nanoparticles (AgNPs) as antibacterial compounds has been widely used in human and veterinary medicine. In this work, we investigated the effects of AgNPs (Argovit-4®) as feed additives (feed-AgNPs) on shrimp (Litopenaeus vannamei) using three different methods: 1) chronic toxicity after 28 days of feeding, 2) Effects against white spot syndrome virus (WSSV) challenged by oral route, and 3) transcriptional responses of immune-related genes (PAP, ProPO, CTL-3, Crustin, PEN3, and PEN4) following WSSV infection. The results showed that the feed-AgNPs did not interfere with the growth and survival of shrimp. Also, mild lesions in the hepatopancreas were recorded, proportional to the frequency of the feed-AgNP supply. Challenge test versus WSSV showed that feeding every 7 days with feed-AgNPs reduced mortality, reaching a survival rate of 53%, compared to the survival rates observed in groups fed every 4 days, daily and control groups of feed-AgNPs for the 30%, 10%, and 7% groups, respectively. Feed-AgNPs negatively regulated the expression of PAP, ProPO, and Crustin genes after 28 days of treatment and altered the transcriptional responses of PAP, ProPO, CTL-3, and Crustin after WSSV exposure. The results showed that weekly feeding-AgNPs could partially prevent WSSV infection in shrimp culture. However, whether or not transcriptional responses against pathogens are advantageous remains to be elucidated.

Evaluation of the Efficacy and Safety of Silver Nanoparticles in the Treatment of Non-Neurological and Neurological Distemper in Dogs: A Randomized Clinical Trial.

Canine distemper is caused by canine distemper virus (CDV), a multisystemic infectious disease with a high morbidity and mortality rate in dogs. Nanotechnology represents a development opportunity for new molecules with antiviral effects that may become effective treatments in veterinary medicine. This study evaluated the efficacy and safety of silver nanoparticles (AgNPs) in 207 CDV, naturally infected, mixed-breed dogs exhibiting clinical signs of the non-neurological and neurological phases of the disease. Group 1a included 52 dogs (experimental group) diagnosed with non-neurologic distemper treated with 3% oral and nasal AgNPs in addition to supportive therapy. Group 1b included 46 dogs (control group) diagnosed with non-neurological distemper treated with supportive therapy only. Group 2a included 58 dogs with clinical signs of neurological distemper treated with 3% oral and nasal AgNPs in addition to supportive therapy. Group 2b included 51 dogs (control group) diagnosed with clinical signs of neurological distemper treated with supportive therapy only. Efficacy was measured by the difference in survival rates: in Group 1a, the survival rate was 44/52 (84.6%), versus 7/46 in Group 1b (15.2%), while both showed clinical signs of non-neurological distemper. The survival rate of dogs with clinical signs of neurological distemper in Group 2a (38/58; 65.6%) was significantly higher than those in Control Group 2b (0/51; 0%). No adverse reactions were detected in experimental groups treated with AgNPs. AgNPs significantly improved survival in dogs with clinical signs of neurological and non-neurological distemper. The use of AgNPs in the treatment of neurological distemper led to a drastic increase in the proportion of dogs recovered without sequels compared to dogs treated without AgNPs. The evidence demonstrates that AgNP therapy can be considered as a targeted treatment in dogs severely affected by canine distemper virus.

The Effect of Sibunit Carbon Surface Modification with Diazonium Tosylate Salts of Pd and Pd-Au Catalysts on Furfural Hydrogenation.

Herein, we investigated the effect of the support modification (Sibunit carbon) with diazonium salts of Pd and Pd-Au catalysts on furfural hydrogenation under 5 bars of H2 and 50 °C. To this end, the surface of Sibunit (Cp) was modified with butyl (Cp-Butyl), carboxyl (Cp-COOH) and amino groups (Cp-NH2) using corresponding diazonium salts. The catalysts were synthesized by the sol immobilization method. The catalysts as well as the corresponding supports were characterized by Fourier transform infrared spectroscopy, N2 adsorption-desorption, inductively coupled plasma atomic emission spectroscopy, high resolution transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, Hammet indicator method and X-ray photoelectron spectroscopy. The analysis of the results allowed us to determine the crucial influence of surface chemistry on the catalytic behavior of the studied catalysts, especially regarding selectivity. At the same time, the structural, textural, electronic and acid-base properties of the catalysts were practically unaffected. Thus, it can be assumed that the modification of Sibunit with various functional groups leads to changes in the hydrophobic/hydrophilic and/or electrostatic properties of the surface, which influenced the selectivity of the process.

Silver Nanoparticles Targeting the Drug Resistance Problem of Streptococcus dysgalactiae: Susceptibility to Antibiotics and Efflux Effect.

The present work is a continuation of our translational research focusing on the use of silver nanoparticles (AgNPs) to solve the global problem of antibiotic resistance. In vivo fieldwork was done with 300 breeding farm cows with serous mastitis. Ex vivo assays revealed that after cow treatment with the antibiotic drug Spectromast LCTM, S.dysgalactiae susceptibility to 31 antibiotics dropped by 22.9%, but after treatment with Argovit-CTM AgNPs, it was raised by 13.1%. This was explained by the fact that the percentage of isolates with an efflux effect after Spectromast LC treatment resulted in an 8% increase, while Argovit-C-treatment caused a 19% decrease. The similarity of these results to our previous results on S. aureus isolates from mastitis cows treated with the antibiotic drug Lactobay and Argovit-CTM AgNPs was shown. So, mastitis treatments with Argovit-CTM AgNPs can partially return the activity of antibiotics towards S.dysgalactiae and S. aureus, while, in contrast, treatments with antibiotic drugs such as Spectromast LC and Lactobay enhance bacterial resistance to antibiotics. The results of this work strengthen the hope that in the future the use of AgNPs as efflux pump inhibitors will recover the activity of antibiotics, and thus will preserve the wide spectrum of antibiotics on the market.

AgNPs Targeting the Drug Resistance Problem of Staphylococcus aureus: Susceptibility to Antibiotics and Efflux Effect.

The present work presents translational research with application of AgNPs targeting the global drug resistance problem. In vivo fieldwork was carried out with 400 breeding farm cows sick with a serous mastitis. Ex vivo results revealed that after cow treatment with LactobayTM (a mixture of antibiotic drugs) the susceptibility to 31 antibiotics of S. aureus isolates from cow breast secretion decreased by 25%, while after treatment with Argovit-CTM silver nanoparticles S. aureus susceptibility increased by 11%. The portion of isolates with an efflux effect leading to elimination of antibiotics from S. aureus after Lactobay-treatment resulted in a 15% increase, while Argovit-C-treatment led to a 17.5% decrease. The obtained results showed that mastitis treatments with Argovit-CTM AgNPs can partially restore the activity of antibiotics towards S. aureus and shorten the duration of mastitis treatment by 33%.

Bell Shape Curves of Hemolysis Induced by Silver Nanoparticles: Review and Experimental Assay.

The hemolytic activity assay is a versatile tool for fast primary toxicity studies. This work presents a systematic study of the hemolytic properties of ArgovitTM silver nanoparticles (AgNPs) extensively studied for biomedical applications. The results revealed an unusual and unexpected bell-shaped hemolysis curve for human healthy and diabetic donor erythrocytes. With the decrease of pH from 7.4 and 6.8 to 5.6, the hemolysis profiles for AgNPs and AgNO3 changed dramatically. For AgNPs, the bell shape changed to a step shape with a subsequent sharp increase, and for AgNO3 it changed to a gradual increase. Explanations of these changes based on the aggregation of AgNPs due to the increase of proton concentration were suggested. Hemolysis of diabetic donor erythrocytes was slightly higher than that of healthy donor erythrocytes. The meta-analysis revealed that for only one AgNPs formulation (out of 48), a bell-shaped hemolysis profile was reported, but not discussed. This scarcity of data was explained by the dominant goal of studies consisting in achieving clinically significant hemolysis of 5-10%. Considering that hemolysis profiles may be bell-shaped, it is recommended to avoid extrapolations and to perform measurements in a wide concentration interval in hemolysis assays.

Search for Effective Approaches to Fight Microorganisms Causing High Losses in Agriculture: Application of P. lilacinum Metabolites and Mycosynthesised Silver Nanoparticles.

The manuscript presents the first report to produce silver nanoparticles (AgNPs) using soil-inhabiting Purpureocillium lilacinum fungus cell filtrate as a promising fungicide and nematicide on two microorganisms causing high economic losses in agriculture. METHODS: A fungus biomass was used as a reducing and stabilising agent in the process of NPs synthesis and then characterisation done by SEM, TEM, UV-Vis. Finally, the antimicrobial activity of the synthesised AgNPs was determined. RESULTS: Synthesised AgNPs with a spherical and quasi-spherical shape with an average diameter of 50 nm were effective to inhibit A. flavus fungi and M. incognita root knot nematode, which are extremely pathogenic for plants. Application of the AgNPs led to 85% reduction of proliferation of A. flavus, to a 4-fold decrease of hatching of M. incognita plant-parasite juveniles from eggs, and to a 9-fold increase of M. incognita nematode mortality. CONCLUSIONS: Biosynthesised AgNPs can be used as an effective fungicide and nematicide for food safety and security and improvement of agricultural production, but further agricultural field trials are required to observe their effect on environment and other factors.

Treatment with Argovit® Silver Nanoparticles Induces Differentiated Postharvest Biosynthesis of Compounds with Pharmaceutical Interest in Carrot (Daucus carota L.).

The global market for plant-derived bioactive compounds is growing significantly. The use of plant secondary metabolites has been reported to be used for the prevention of chronic diseases. Silver nanoparticles were used to analyze the content of enhancement phenolic compounds in carrots. Carrot samples were immersed in different concentrations (0, 5, 10, 20, or 40 mg/L) of each of five types of silver nanoparticles (AgNPs) for 3 min. Spectrophotometric methods measured the total phenolic compounds and the antioxidant capacity. The individual phenolic compounds were quantified by High Performance Liquid Chromatography (HPLC) and identified by -mass spectrometry (HPLC-MS). The five types of AgNPs could significantly increase the antioxidant capacity of carrots' tissue in a dose-dependent manner. An amount of 20 mg/L of type 2 and 5 silver nanoparticle formulations increased the antioxidant capacity 3.3-fold and 4.1-fold, respectively. The phenolic compounds that significantly increased their content after the AgNP treatment were chlorogenic acid, 3-O-caffeoylquinic acid, and 5'-caffeoylquinic acid. The increment of each compound depended on the dose and the type of the used AgNPs. The exogenous application of Argovit® AgNPs works like controlled abiotic stress and produces high-value secondary bioactive compounds in carrot.

The Infectious Bronchitis Coronavirus Pneumonia Model Presenting a Novel Insight for the SARS-CoV-2 Dissemination Route.

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.

Antitumor Activity against Human Colorectal Adenocarcinoma of Silver Nanoparticles: Influence of [Ag]/[PVP] Ratio.

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.

AgNPs Argovit™ Modulates Cyclophosphamide-Induced Genotoxicity on Peripheral Blood Erythrocytes In Vivo.

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.

Evaluation of silver nanoparticles for the prevention of SARS-CoV-2 infection in health workers: In vitro and in vivo.

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.

Hemolysis of Human Erythrocytes by Argovit™ AgNPs from Healthy and Diabetic Donors: An In Vitro Study.

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.

Antibacterial and Antifungal Studies of Biosynthesized Silver Nanoparticles against Plant Parasitic Nematode Meloidogyne incognita, Plant Pathogens Ralstonia solanacearum and Fusarium oxysporum.

The possibility of using silver nanoparticles (AgNPs) to enhance the plants growth, crop production, and control of plant diseases is currently being researched. One of the most effective approaches for the production of AgNPs is green synthesis. Herein, we report a green and phytogenic synthesis of AgNPs by using aqueous extract of strawberry waste (solid waste after fruit juice extraction) as a novel bioresource, which is a non-hazardous and inexpensive that can act as a reducing, capping, and stabilizing agent. Successful biosynthesis of AgNPs was monitored by UV-visible spectroscopy showing a surface plasmon resonance (SPR) peak at ~415 nm. The X-ray diffraction studies confirm the face-centered cubic crystalline AgNPs. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques confirm the rectangular shape with an average size of ~55 nm. The antibacterial and antifungal efficacy and inhibitory impact of the biosynthesized AgNPs were tested against nematode, Meloidogyne incognita, plant pathogenic bacterium, Ralstonia solanacearum and fungus, Fusarium oxysporum. These results confirm that biosynthesized AgNPs can significantly control these plant pathogens.