Efectividad antimicrobiana de los sistemas adhesivos. Una alternativa eficaz: revisión bibliográfica / Antimicrobial effectiveness of adhesive systems. An effective alternative: literature review / Eficácia antimicrobiana dos sistemas adesivos. Uma alternativa eficaz: revisão da literatura

RESUMEN Los sistemas adhesivos se utilizan en la práctica clínica diaria; sin embargo, su principal desventaja es la contracción por polimerización que podría ocasionar la aparición de microfiltraciones, acumulo de placa, caries secundaria e hipersensibilidad. Por este motivo, se han venido incorporando agentes antimicrobianos, como el metacrilato de amonio cuaternario fotopolimerizable, los rellenos de vidrio que liberan iones de flúor, el pirogalol y las nanopartículas de plata, calcio y grafeno fluorado. En los últimos años, algunos de estos han demostrado tener una buena efectividad antimicrobiana, que, a su vez, no interfieren con la adhesión en las restauraciones. De tal manera, estos sistemas adhesivos antimicrobianos podrían favorecer a obtener mejores resultados a largo plazo. Las nanopartículas que presentaron mejores resultados fueron el fosfato de calcio amorfo y las compuestas de plata.

ABSTRACT Adhesive systems are used in daily clinical practice; however, the main disadvantage is polymerization shrinkage, which could lead to microleakage, plaque accumulation, secondary caries, and hypersensitivity. For this reason, antimicrobial agents have been incorporated, such as light-curing quaternary ammonium methacrylate, fluoride ion-releasing glass fillers, pyrogallol, and nanoparticles of silver, calcium, and fluorinated graphene. In recent years, some of these have been shown to have good antimicrobial effectiveness and, in turn, do not interfere with adhesion in restorations. Thus, these antimicrobial adhesive systems could contribute to better long-term results. The best-performing nanoparticles were amorphous calcium phosphate and silver nanoparticles.

RESUMO Os sistemas adesivos são utilizados na prática clínica diária; no entanto, a principal desvantagem é a contração da polimerização, que pode levar a microinfiltração, acumulação de placa, cáries secundárias e hipersensibilidade. Por este motivo, foram incorporados agentes antimicrobianos, como o metacrilato de amónio quaternário fotopolimerizável, cargas de vidro que libertam iões de flúor, pirogalol e nanopartículas de prata, cálcio e grafeno fluorado. Nos últimos anos, algumas destas substâncias demonstraram ter uma boa eficácia antimicrobiana e não interferem com a adesão nas restaurações. Assim, estes sistemas adesivos antimicrobianos poderiam conduzir a melhores resultados a longo prazo. As nanopartículas com melhor desempenho foram o fosfato de cálcio amorfo e as nanopartículas de prata.

Research progress on drug combination therapy against Candida albicans / 药学实践与服务

Candida albicans is one of the most common species of Candida, which is an important cause of invasive candidiasis in clinic. Due to the frequently use of classical antifungal agents, there are amounts of drug resistant C. albicans being isolated, causing the significantly decreasing of the efficacy of some antifungal agents in clinical treatment. Besides, the use of some compounds in clinic has been limited because of their toxicities. In such a context, drug combination therapy shows great potential on antifungal because of the synergy of different drugs or therapeutic methods that could bring, which could improve the weaknesses of single drug.

The use of biosynthesized silver nanoparticles from Klebsiella pneumonia as antioxidants and anti-bacterial agents

Aims@#This study was aimed at the biosynthesis of silver nanoparticles (AgNPs) from Klebsiella pneumonia and the evaluation of their anti-bacterial and antioxidant activities. @*Methodology and results@#Silver nitrate was used for the biosynthesis of silver-nanoparticles, and UV-visible spectrophotometer, X-ray diffraction, scanning electron microscope and Fourier transforms infrared spectroscopy were used for the characterization of AgNPs. Results showed colour changes of bacterial supernatant from pale yellow to dark brown, indicating the biosynthesis of AgNPs. The biosynthesis of AgNPs was confirmed using UV-visible spectrophotometry, which shows a strong peak at 420 nm. Infrared spectroscopy was also used, which revealed that the carboxyl and phenolic groups were coated on the surface of AgNPs. The results of the electron microscope scanning showed that AgNPs are spherical and have a size range from 35-100 nm. On the other hand, the antioxidant activity of AgNPs was done in vitro by adding the nanoparticles to the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) solution. The absorbance was measured at 517 nm after 30 min in dark conditions. The results revealed a significant increase (P<0.05) in free radicals reduction at five concentrations of AgNPs (30, 60, 120, 240 and 480 µg/mL). Finally, the antibacterial activity of AgNPs against Escherichia coli and Pseudomonas aeruginosa was studied. The results revealed a significant increase (P<0.05) in the diameter of the inhibition zone of bacterial growth at 200 µg/mL AgNPs compared to the inhibition zone at 50 and 100 µg/mL AgNPs. The minimum inhibitory concentration of AgNPs was determined. It was 30 µg/mL of P. aeruginosa and 16 µg/mL of E. coli.@*Conclusion, significance and impact of study@#The preliminary study results suggest that AgNPs have anti-bacterial activity as well as the ability to inhibit free radicals, making them a potential antioxidant source. However, further research is required.

Viral disease control in strawberry plants: A potential impact of green nanotechnology

Aims@#Strawberry (Fragaria ananassa Duch.) is a member of the family Rosaceae and one of the most important vegetable crops in Egypt for local fresh consumption and exportation. Suspected symptoms of Strawberry mild yellow edge virus (SMYEV) on naturally infected strawberry plants were observed in Al Qaluobia Governorate. The main goal of this study was to develop a novel eco-friendly biogenic silver nanoparticle using clove (Syzygium aromaticum) (SzAgNPs) aqueous extract to control viral infection.@*Methodology and results@#Mechanically inoculated sixteen plant species representing seven families, Apocynaceae, Chenopodiaceae, Cucurbitaceae, Fabaceae, Moraceae, Rosaceae and Solanaceae, were used as hosts for SMYEV. Systemic mosaic, chlorotic local lesions, vein clearing, marginal chlorosis, marginal necrosis, yellowing and vein banding were observed 7 to 20 days post-inoculation. Transmission electron microscopy (TEM) of diseased tissues revealed severe degeneration of the chloroplasts and nucleus structures and the formation of cell wall protrusions. Sz-AgNPs were characterized using UV-Vis spectroscopy, TEM, dynamic light scattering (DLS) and Fourier transform infrared (FTIR). Foliar application of Sz-AgNPs (200 µg/mL) 24 h post and/or concurrently with SMYEV inoculation dropped the infection rate by 90% and 55%, respectively, whereas it was only reduced by 35% when applied 24 h prior to viral inoculation compared to control groups. DAS-ELISA and RT-PCR verified SMYEV inhibition (75-90%) in all plants treated with 200, 150 and 100 µg/mL Sz-AgNPs 24 h post-viral inoculation. Complete viral eradication was attained by applying Sz-AgNPs at a concentration of 200 μg/mL 24 h post-virus inoculation. Moreover, the total phenols, indoles, Vitamin C, total flavonoids and citric acid contents were not significantly affected by Sz-AgNPs treatment compared to healthy control groups.@*Conclusion, significance and impact of study@#In conclusion, Sz-AgNPs suppressed SMYEV by 75-90% when applied 24 h post-virus inoculation. Eco-friendly Sz-AgNPs could be used for controlling viral infections and avoiding the rejection of exportable strawberries due to the use of harmful pesticides.

Inhibitory effects of Ag+ and ZnO+ nanoparticles on a causative agent (Neoscytalidium dimidiatum) of dragon fruit stem-canker

Aims@#This study aimed to isolate the fungal strains causing brown spot disease on dragon fruit and identify them using molecular biology techniques. The study also investigated the inhibitory effects of silver (Ag) and ZnO nanoparticles on the isolated fungal strains. @*Methodology and results @#Six fungal strains (TL1, TL2, TL3, TL4, TL5, TL6) causing brown spot disease (stem-canker) were isolated. TL1 and TL2 isolates were used for testing the antifungal features of nanoparticles. Nanoparticles were directly added to the PDA medium to make a solution with concentrations of 50, 75 and 100 ppm. The antifungal feature of nanoparticles was screened by inoculating with the fungal samples for 72 h. The inhibitory capacity of ZnO and Ag nanoparticles against fungal strains was then investigated. TL1 and TL2 samples were identified as Neocytalidium dimidiatum using the internal transcribed spacer (ITS) region. The study also revealed that silver nanoparticles were more effective than zinc oxide nanoparticles in inhibiting the growth of fungal strains that cause brown spot disease on dragon fruit. Specifically, ZnO nanoparticles had the highest inhibitory effect on TL2, 61.27% at 100 ppm and Ag nanoparticles gave the highest inhibitory effect on TL2, 85.83% at 100 ppm.@*Conclusion, significance and impact of study @#The research findings suggest that the use of Ag and ZnO nanoparticles may be an effective way to control brown dragon fruit spot disease. It may help in improving dragon fruit yield and aesthetic quality. As a result, it may help in reducing economic loss for farmers. However, further research is required.

Cellular Uptake of Catharanthus roseus-Silver Nanoparticles in Human Hepatocellular Carcinoma HepG2 Cells

@#Introduction: Nanoparticles exhibit unique features and currently at the forefront of cutting-edge research. Silver nanoparticles (AgNPs) are among the most promising and widely commercialised nanoproducts in various fields. The interaction of these AgNPs with cells remain unclear to connect with its toxicological endpoints. The aim of this study was to investigate the cellular uptake of C. roseus-AgNPs in hepatocellular carcinoma cells HepG2. Methods: The HepG2 cells were treated with the mean IC50 value of C. roseus-AgNPs which was 4.95±0.26 µg/mL for 24, 48 and 72 hours. The effects were compared with the untreated cells and other treatments which include camptothecin, C. roseus-aqueous extract, and AgNO3 . Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to quantify the intracellular Ag+ and Ca2+, while transmission electron microscopy (TEM) imaging was used to visualise the nanoparticle distribution. Results: The HepG2 cells have significantly taken up Ag+ from C. roseus-AgNPs with at least six times higher compared to Ag+ from AgNO3 . The intracellular Ca2+ detected in HepG2 cells for all treatments were significantly higher than the untreated cells, in time-dependent manner. TEM images indicated the endocytosis of C. roseus-AgNPs with the presence of endosomes and exocytic vesicles. Conclusion: The significant accumulation of intracellular Ag+ demonstrated the efficiency of the C. roseus-AgNPs uptake while the increased Ca2+ indicated the early sign of cell injury. The cellular uptake was mainly through endocytosis. These findings are crucial to correlate the physicochemical properties of C. roseus-AgNPs with the anticancer mechanisms towards the development of liver cancer therapy.

Silver nanoparticles-resistance of HeLa cell associated with its unusually high concentration of α-ketoglutarate and glutathione / 生物工程学报

Silver nanoparticles (AgNPs) is known as one of the most valuable metal nanoparticles in antibacterial and anticancer application. AgNPs-resistant bacteria has been documented, but it is unclear whether cancer cells can also escape the anti-cancer effect of AgNPs. In this study, we aimed to investigate this phenomenon and its underlying mechanism. The antibacterial activity and cytotoxicity of AgNPs were measured in the presence of HeLa cell metabolites. The status of AgNPs in the system associated with metabolites were characterized by UV-Vis, Zetasizer Nano ZS, and transmission electron microscopy. Non-targeted metabolomics was used to reveal the metabolites components that bind with AgNPs. HeLa cells were injected intraperitoneally to establish the tumor-bearing mice model, and the stability of AgNPs in mice serum was analyzed. The results manifested that HeLa cell metabolites inhibited the anticancer and antibacterial effects of AgNPs in a dose-dependent manner by causing AgNPs aggregation. Effective metabolites that inhibited the biological activity of AgNPs were stable in 100 ℃, insoluble in chloroform, containing sulfur elements, and had a molecular weight less than 1 kDa in molecular weight. There were 115 compounds bound with AgNPs. In vitro experiments showed that AgNPs aggregation occurred only when the concentration of α-ketoglutarate (AKG) and glutathione (GSH) together reached a certain threshold. Interestingly, the concentration of AKG and GSH in HeLa cellular metabolites was 10 and 6 times higher than that in normal cervical epithelial cells, respectively, which explained why the threshold was reached. Furthermore, the stability of AgNPs in the serum of tumor-bearing mice decreased by 20% (P < 0.05) compared with the healthy mice. In conclusion, our study demonstrates that HeLa cells escaped the anti-cancer effect of AgNPs through the synergistic effect of AKG and GSH, suggesting the need to develop strategies to overcome this limitation.

Antioxidant and antimicrobial activities of Thymus vulgaris essential oil contained and synthesis thymus (Vulgaris) silver nanoparticles / Atividades antioxidante e antimicrobiana do óleo essencial de Thymus vulgaris contido e síntese de nanopartículas de prata de timo (Vulgaris)

Several species of thymus have therapeutic properties, so they are used in traditional medicine. In this work was carried out to synthesize Thymus vulgalis silver nanoparticles (TSNPS) and evaluate antioxidant and antimicrobial activities of TSNPS and T. vulgalis essential oil extract (TEOE). The essential oils analyzed by GC-MS and were characterized. Major compounds of phenol, 2 methyl 5 (1 methylethyle) (CAS), thymol and 1,2 Benzene dicarboxylic acid, 3 nitro (CAS) (48.75%, 32.42% and 8.12%, respectively) were detected. Results demonstrated that the TSNPS gave a highest DPPH radical scavenging activity, it was obtained 97.2 at 1000 ug/ml. TSNPS, Thymus + Hexane (T+H), Thymus + Ethanol (T+E) gave the greatest antimicrobial activity than amoxicillin (AM) and ciprofloxacin (CIP). In conclusion: The essential oil of thymus (Vulgaris) and thymus (Vulgaris) silver nanoparticles can be a good source of natural preservatives as an antioxidant and antimicrobial agents for increasing the shelf life of foodstuffs.

Diversas espécies de timo possuem propriedades terapêuticas, por isso são utilizadas na medicina tradicional. Neste trabalho foi realizado para sintetizar nanopartículas de prata Thymus vulgalis (TSNPS) e avaliar as atividades antioxidante e antimicrobiana de TSNPS e extrato de óleo essencial de T. vulgalis (TEOE). Os óleos essenciais analisados por GC-MS e foram caracterizados. Os principais compostos de fenol, 2 metil 5 (1 metiletilo) (CAS), timol e ácido 1,2 Benzenodicarboxílico, 3 nitro (CAS) (48,75%, 32,42% e 8,12%, respectivamente) foram detectados. Os resultados demonstraram que o TSNPS deu uma maior atividade de eliminação do radical DPPH , foi obtido 97,2 a 1000 ug / ml. TSNPS, Timo + Hexano (T + H), Timo + Etanol (T + E) deu a maior atividade antimicrobiana do que amoxicilina (AM) e ciprofloxacina (CIP). Em conclusão: O óleo essencial de nanopartículas de prata do timo (Vulgaris) e do timo (Vulgaris) pode ser uma boa fonte de conservantes naturais como agentes antioxidantes e antimicrobianos para aumentar a vida útil de alimentos.

Antioxidant and antimicrobial activities of Thymus vulgaris essential oil contained and synthesis thymus (Vulgaris) silver nanoparticles

Abstract Several species of thymus have therapeutic properties, so they are used in traditional medicine. In this work was carried out to synthesize Thymus vulgalis silver nanoparticles (TSNPS) and evaluate antioxidant and antimicrobial activities of TSNPS and T. vulgalis essential oil extract (TEOE). The essential oils analyzed by GC-MS and were characterized. Major compounds of phenol, 2 methyl 5 (1 methylethyle) (CAS), thymol and 1,2 Benzene dicarboxylic acid, 3 nitro (CAS) (48.75%, 32.42% and 8.12%, respectively) were detected. Results demonstrated that the TSNPS gave a highest DPPH radical scavenging activity, it was obtained 97.2 at 1000 ug/ml. TSNPS, Thymus + Hexane (T+H), Thymus + Ethanol (T+E) gave the greatest antimicrobial activity than amoxicillin (AM) and ciprofloxacin (CIP). In conclusion: The essential oil of thymus (Vulgaris) and thymus (Vulgaris) silver nanoparticles can be a good source of natural preservatives as an antioxidant and antimicrobial agents for increasing the shelf life of foodstuffs.

Resumo Diversas espécies de timo possuem propriedades terapêuticas, por isso são utilizadas na medicina tradicional. Neste trabalho foi realizado para sintetizar nanopartículas de prata Thymus vulgalis (TSNPS) e avaliar as atividades antioxidante e antimicrobiana de TSNPS e extrato de óleo essencial de T. vulgalis (TEOE). Os óleos essenciais analisados por GC-MS e foram caracterizados. Os principais compostos de fenol, 2 metil 5 (1 metiletilo) (CAS), timol e ácido 1,2 Benzenodicarboxílico, 3 nitro (CAS) (48,75%, 32,42% e 8,12%, respectivamente) foram detectados. Os resultados demonstraram que o TSNPS deu uma maior atividade de eliminação do radical DPPH , foi obtido 97,2 a 1000 ug / ml. TSNPS, Timo + Hexano (T + H), Timo + Etanol (T + E) deu a maior atividade antimicrobiana do que amoxicilina (AM) e ciprofloxacina (CIP). Em conclusão: O óleo essencial de nanopartículas de prata do timo (Vulgaris) e do timo (Vulgaris) pode ser uma boa fonte de conservantes naturais como agentes antioxidantes e antimicrobianos para aumentar a vida útil de alimentos.

Antioxidant and antimicrobial activities of Thymus vulgaris essential oil contained and synthesis thymus (Vulgaris) silver nanoparticles / Atividades antioxidante e antimicrobiana do óleo essencial de Thymus vulgaris contido e síntese de nanopartículas de prata de timo (Vulgaris)

Abstract Several species of thymus have therapeutic properties, so they are used in traditional medicine. In this work was carried out to synthesize Thymus vulgalis silver nanoparticles (TSNPS) and evaluate antioxidant and antimicrobial activities of TSNPS and T. vulgalis essential oil extract (TEOE). The essential oils analyzed by GC-MS and were characterized. Major compounds of phenol, 2 methyl 5 (1 methylethyle) (CAS), thymol and 1,2 Benzene dicarboxylic acid, 3 nitro (CAS) (48.75%, 32.42% and 8.12%, respectively) were detected. Results demonstrated that the TSNPS gave a highest DPPH radical scavenging activity, it was obtained 97.2 at 1000 ug/ml. TSNPS, Thymus + Hexane (T+H), Thymus + Ethanol (T+E) gave the greatest antimicrobial activity than amoxicillin (AM) and ciprofloxacin (CIP). In conclusion: The essential oil of thymus (Vulgaris) and thymus (Vulgaris) silver nanoparticles can be a good source of natural preservatives as an antioxidant and antimicrobial agents for increasing the shelf life of foodstuffs.

Resumo Diversas espécies de timo possuem propriedades terapêuticas, por isso são utilizadas na medicina tradicional. Neste trabalho foi realizado para sintetizar nanopartículas de prata Thymus vulgalis (TSNPS) e avaliar as atividades antioxidante e antimicrobiana de TSNPS e extrato de óleo essencial de T. vulgalis (TEOE). Os óleos essenciais analisados por GC-MS e foram caracterizados. Os principais compostos de fenol, 2 metil 5 (1 metiletilo) (CAS), timol e ácido 1,2 Benzenodicarboxílico, 3 nitro (CAS) (48,75%, 32,42% e 8,12%, respectivamente) foram detectados. Os resultados demonstraram que o TSNPS deu uma maior atividade de eliminação do radical DPPH , foi obtido 97,2 a 1000 ug / ml. TSNPS, Timo + Hexano (T + H), Timo + Etanol (T + E) deu a maior atividade antimicrobiana do que amoxicilina (AM) e ciprofloxacina (CIP). Em conclusão: O óleo essencial de nanopartículas de prata do timo (Vulgaris) e do timo (Vulgaris) pode ser uma boa fonte de conservantes naturais como agentes antioxidantes e antimicrobianos para aumentar a vida útil de alimentos.

Biofabrication and optimization of silver nanoparticles using Campsis sp. to explore their antimicrobial properties

Plant mediated green synthesis of silver nanoparticles (AgNPs) holds promising applications in the field of Biomedicine, Food packaging and Wound healing. In the present investigation, biofabrication of AgNPs was performed using the aqueous extracts of Campsis sp. (Family Bignoniaceae) leaves and flowers growing in the premises of Kirori Mal College, University of Delhi, Delhi. Optimization of AgNPs was performed to analyse the varying effect of pH (6.0, 8.0, 10.0) and silver salt concentration (2mM, 4Mm and 6Mm) in controlling the shape and size of AgNPs which in turn governs their further applications. Interestingly, change in colour of the reaction mixture from pale yellow to reddish brown indicated the formation of AgNPs. These AgNPs were further characterized by UV-Visible spectroscopy and showed peak in the range of 400-450 nm which confirmed the synthesis of silver nanoparticles. Dynamic light scattering and zeta potential analysis (DLS-Zeta) confirmed the size of AgNPs around 200-300 nm. A significant zone of inhibition was observed for both Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative) bacterial strains which revealed the antimicrobial potential of Campsis sp. AgNPs. Therefore, Campsis AgNPs may provide a green, eco-sustainable alternate method for sustainable production of nanomaterials for biomedical applications. These AgNPs may also show tremendous applications in food packaging, wound healing and biomedical fields.

Nanopartículas de plata contra bacterias presentes en biofilm dental de pacientes pediátricos / Silver nanoparticles against bacteria present in dental biofilm of pediatric patients

Introducción: el biofilm dental microbiano es el precursor de diversas enfermedades orales, una de ellas la caries, ésta representa la enferme- dad oral más significativa a nivel mundial, con una incidencia de 1.76 billones de niños afectados. Las nanopartículas de plata (AgNPs) se están usando como alternativa para el control y prevención del biofilm dental, ya que poseen propiedades antimicrobianas contra bacterias relacionadas a estas enfermedades. Sin embargo, no hay estudios que evalúen este comportamiento en pacientes pediátricos. Objetivo: eva- luar la actividad antimicrobiana de las AgNPs en bacterias de aislados clínicos tomados de pacientes pediátricos. Material y métodos: se tomó muestra del biofilm dental de 22 pacientes pediátricos, el efecto micro- biológico se evaluó mediante ensayos microbiológicos estandarizados internacionalmente por triplicado, usando dos diferentes tamaños de AgNPs. Resultados: los dos tamaños de AgNPs mostraron inhibición bacteriana, sin embargo, sólo se vio una diferencia estadísticamente significativa entre el género (p < 0.05), además, en general, hubo una correlación positiva significativa en relación a la concentración de las AgNPs y la velocidad del crecimiento bacteriano (p < 0.05). Conclusión: las AgNPs se pueden considerar como una alternativa para la prevención del biofilm dental y de esta manera para el control de diferentes enfermedades orales (AU))

Introduction: dental biofilm is the precursor of oral diseases, one of them dental caries, this represents the most significant oral disease worldwide with an incidence of 1.76 billion affected children. Silver nanoparticles (AgNPs) are being used as an alternative for the control and prevention of dental biofilm since they have antimicrobial properties against bacteria related to these diseases. However, there are no studies evaluating this behavior in pediatric patients. Objective: to evaluate the antimicrobial activity of AgNPs in bacteria from clinical isolates taken from pediatric patients. Material and methods: a sample of dental biofilm was taken from 22 pediatric patients, the microbiological effect was evaluated by international standardized microbiological tests in triplicate, using two different sizes of AgNPs. Results: the two sizes of AgNPs showed bacterial inhibition, however, only a statistically significant difference was seen between gender (p < 0.05), in addition, in general, there was a significant positive correlation in relation to the concentration of AgNPs and the speed bacterial growth (p < 0.05). Conclusion: AgNPs can be considered as an alternative for the prevention of dental biofilm and thus for the control of different oral diseases (AU)

Exploiting the potential of bio-synthesized silver nanoparticles to enhance the shelf life of Gladiolus

Gladiolus spikes with fully turgid petals need to have a longer shelf life to fetch a higher price as well as display value. To improve the life duration of ornamental flowers, the ability of plants to produce silver nanoparticles (AgNP) was exploited. The ability of plants to produce AgNP when treated with silver nitrate solutions was juxtaposed by using Gladiolus (cut flowers): (i) To find the appropriate concentration of AgNO3 suitable for increasing shelf-life of Gladiolus cut flowers; (ii) To prepare silver nanoparticle from AgNO3; and (iii) To confirm the formation of silver nanoparticle using UV-vis spectrophotometry. Two different reductants (dehydrogenases present at the surface of the plant cells and sucrose) demonstrated the reduction of Ag+ to generate AgNPs. DLS (Dynamic Light Scattering) study revealed the presence of NPs in the AgNO3 salt solution incubated with Gladiolus cut flowers. The DLS data also suggested that the size of AgNPs decreased with increasing concentration of AgNO3. In the present study, along with silver nitrate, sucrose was also used. The shelf life and display value of the cut Gladiolus can be increased and optimized by incubating it in sucrose solution in combination with AgNO3.

Synthesis of Silver Nanoparticles Using Flavonoid Hesperidin and Pharmacological Evaluation of its Free Radical Scavenging Activity

Background: Silver Nanoparticles are drawing significant attention from the scientific community to explore a wide range of its medical applications. Human body is under constant stress due to free radicals generated by the physiological and pathological conditions in the body. Scavenging systems or Antioxidants can help alleviate the damages caused by these radicals which can influence the course of progress in several chronic diseases with an inflammatory background. External antioxidants supplement and facilitate the overwhelmed scavenging systems in the body.Silver Nanoparticles can enhance the therapeutic effects of phytochemicals. Aim: To Synthesize silver nanoparticles using the phytochemical Hesperidin and studying its Free radical scavenging activity. Methods: Silver Nanoparticles are synthesized using chemical reduction method. The synthesis is confirmed using spectrophotometric studies. Free Radical scavenging activity is detected using 1, 1-diphenyl-2-picrylhydrazyl (DPPH �) free radical scavenging assay. Results: Silver nanoparticles were successfully synthesized which was confirmed by the change in color of the solution and peak absorbance peak at 420 nM on spectrophotometric studies.Hesperidin Silver Nanoparticles exhibited higher free radical scavenging activity when compared with pure hesperidin and standard Ascorbic acid. Conclusion: Hesperidin can ideally be used for the synthesis of silver nanoparticles and the synthesized Silver Nanoparticles enhances the free radical scavenging activity of Hesperidin which can further be evaluated by In Vivo studies.

Evaluation of the In Vitro Cytotoxicity of Silver Nanoparticles on PBMC Cells Using MTT Assay

Background: Silver Nanoparticles are extensively studied by the scientific community for therapeutic applications. With respect to the fundamental pillars of bioethics 揚rimum non nocere� equal emphasis should be given to evaluate the toxicological perspectives of Silver nanoparticles. This study aims at evaluating the InVitro cytotoxic effects of Silver nanoparticles synthesized using hesperidin. Aim: To study the In Vitro cytotoxicity of silver nanoparticles on PBMC cells using (3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Methods: Synthesized silver nanoparticles at various concentrations are incubated with peripheral blood mononuclear cells (PBMC). After 24 hours MTT is added to the mixture to evaluate the cell viability post incubation. Yellow MTT (a tetrazole) which is reduced to purple formazan in the mitochondria of living cells. The absorbance of this colored solution can be quantified by measuring at 570 nm by a spectrophotometer. This reduction takes place only when mitochondrial reductase enzymes are active, and therefore conversion can be directly related to the number of viable (living) cells. Results: ?.Conclusion: Silver Nanoparticles do not exhibit any significant cytotoxicity on PBMCs and also there were no dose dependent trends in the results.

Avaliação de alumina e carvão ativado conjugados com nanopartículas de prata como pré-tratamentos para nanofiltração visando à redução da incrustação / Evaluation of alumina and activated carbon conjugated to silvernanoparticles as nanofiltration pre-treatments aiming at fouling reduction

RESUMO A má distribuição geográfica de águas em território nacional aliada ao seu desperdício, à poluição dos cursos d'água próximos aos centros urbanos e industriais e à eficiência inadequada de processos de tratamento convencionais faz com que o tratamento e o reúso de água sejam tópicos de crescente importância no Brasil. Um dos métodos de tratamento de água são os processos de separação por membranas, como a nanofiltração. No entanto, esses processos estão sujeitos ao fenômeno de incrustação, que provoca diminuição gradativa de sua eficiência. Sendo assim, o presente trabalho visou à avaliação de diferentes métodos de pré-tratamento de água para mitigação da formação de biofilme em membranas de nanofiltração. Os processos de adsorção em partículas de alumina e desinfecção por meio de carvão ativado impregnado com nanopartículas de prata foram aplicados em uma amostra de um corpo d'água superficial. As amostras com e sem pré-tratamento foram nanofiltradas e a propensão à incrustação de cada uma foi avaliada. As eficiências de remoção de compostos orgânicos dos adsorventes empregados separadamente e em conjunto e as análises de absorção UV/Vis, microscópio eletrônico de varredura e espectroscopia de energia dispersiva do carvão ativado impregnado com nanopartículas de prata mostraram que os materiais empregados no pré-tratamento puderam ser apropriadamente sintetizados. Foi possível também identificar os principais grupos funcionais dos biopolímeros presentes nos biofilmes formados ao longo do tempo. Por fim, pôde-se observar que a adsorção da matéria orgânica é mais eficiente para o controle da incrustação rápida, enquanto o efeito bactericida se destaca no controle a longo prazo.

ABSTRACT The poor geographical distribution of water in the national territory combined with its waste, the pollution of watercourses close to urban and industrial centers, and the inadequate efficiency of conventional treatment processes make the treatment and reuse of water topics of increasing importance in Brazil. One of the advanced water treatment methods is membrane separation processes, such as nanofiltration. However, these processes are subject to fouling phenomenon, which causes a gradual decrease in the efficiency of the process. Therefore, the present work aims to evaluate different methods of pretreatment of water to mitigate the formation of biofilm in nanofiltration membranes. The adsorption processes on alumina particles and disinfection through activated carbon impregnated with silver nanoparticles were applied to a sample of a surface water body. Samples with and without pretreatment were nanofiltered and the propensity to fouling was evaluated. The efficiency of the adsorbents, used both separately and together, in removing organic compounds and the UV/Vis, scanning electron microscope, and Energy-dispersive X-ray spectroscopy analyses of the activated carbon impregnated with silver nanoparticles showed that the materials used in the pre-treatment were properly synthesized. It was also possible to identify the main functional groups of the biopolymers present in biofilms formed over time. Finally, it was observed that the adsorption of organic matter is more efficient for the control of rapid fouling while the bactericidal effect stands out in the long-term fouling control.

Synergistic antimicrobial activity of honey combined with silver nanoparticles topically applied in experimentally infected wounds in Wistar albino rats

Background: Silver nanoparticles (AgNPs) show ample antibacterial activities when combining with honey. Aim and Objective: The study was designed to determine the antibacterial activity of different kinds of honey against the common wound pathogen Staphylococcus aureus. Materials and Methods: Bacterial strain was used to inoculate the wound. S. aureus ATCC-25923 was used in the study. Results: Wound infection examination was done by total count of bacterial load. In all three groups, better percentage of the wound closer, histological, blood, and tissue parameters identified in honey combine with AgNPs, showed a synergistic effect. Conclusion: Honey and AgNPs showed synergistic effect. It is recommended to apply both the products together.

Mycosynthesis of thermostable silver nanoparticles by the endophytic Albifimbria verrucaria with antimicrobial and antiproliferative activities

Aims@#This study was aimed to screen and isolate soil and endophytic fungi with the ability to biosynthesize stable silver nanoparticles (SNPs) with antimicrobial and antiproliferative activities.@*Methodology and results@#A total of 60 fungal isolates isolated from soil and plant samples were screened for their ability to biosynthesize SNPs. Among which, 21 isolates have supported the biosynthesis of SNPs. Furthermore, the endophytic isolate PRR2.1 synthesized highly thermostable SNPs with long shelf life. The PRR2.1 isolate was identified as Albifimbria verrucaria by morphological and molecular means. The synthesis of SNPs was initially monitored by UV-Vis spectroscopy. Further characterization by transmission electron microscopy, X-ray diffraction and dynamic light scattering revealed well-dispersed spherical crystalline in nature SNPs with a mean size of 14 nm and zeta potential of –24.47 mV. Fourier transform infrared spectroscopy showed the presence of biomolecules adsorbed on the surface of biosynthesized SNPs responsible for their synthesis and stability. The mycosynthesized SNPs exhibited stronger antifungal activity against pathogenic strains of Aspergillus niger, A. flavus, A. fumigatus and Candida albicans with respect to its antibacterial activity against Escherichia coli, Staphylococcus aureus, Bacillus cereus and Klebsiella pneumoniae compared to standard antifungal itraconazole and antibiotic cefadroxil with mostly consistent minimum inhibitory concentration of 5.31 μg/mL. The biosynthesized SNPs demonstrated dose-dependent in vitro antiproliferative activity against cancerous HeLa cell line with IC50 value of 2.52 μg/mL and less cytotoxic activity against WI-38 (normal human lung fibroblasts) cell line with CC50 value of 10.2 μg/mL.@*Conclusion, significance and impact of study@#These results show the potential of endophytic fungi biosynthesized SNPs as possible biofriendly, safe and efficient antimicrobial agents with promising antiproliferative activity and low cytotoxicity, which can be furtherly implemented in various biomedical and biotechnological applications.

Green synthesis of silver nanoparticles using leaf extracts of Mentha arvensis Linn. and demonstration of their in vitro antibacterial activities

Abstract A study was carried out to synthesize silver nanoparticles (Ag-NPs) using plant extracts and to explore their pharmaceutical application as antibacterial agents. Dried leaves of Mentha arvensis Linn. were powdered and extracts were prepared using three different organic solvents. Preliminary screening on antibacterial activity by agar well diffusion method indicated that the methanolic extract possessed higher potential than the other two. Phytochemical analysis of the leaf extract revealed that it possesses tannins, steroids, terpenoids and flavonoids. Ag-NPs prepared using this extract were of spherical to cuboidal shape ranging in size from 40 to 70 nm. It retained essential chemical groups and had the required surface plasmon resonance. Further to the antimicrobial assay, the Ag-NPs, in contrast to the whole methanolic leaf extract, showed better (100% vs. 80%) bactericidal activity against the indicator organisms. The zones of growth inhibition for gram positive bacteria ranged between 14±0.6 and 23±0.3, while it was between 12±0.6 and 22±0.2 for gram negative bacteria. The Ag-NPs presented the minimum inhibitory concentration values of 250 µg/mL for gram positive bacteria and 250 - 500 µg/mL for gram negative bacteria. These findings suggest that the natural compounds present in M. arvensis L. possess the potency to facilitate the synthesis and antibacterial action of Ag-NPs.

Antifungal activity of silver nanoparticles and clotrimazole against Candida spp

Abstract The aim of present study was calculate the Minimum inhibitory concentrations (MICs) of silver nanoparticles and clotrimazole for Candida species and their interaction by the adaptation of standarized methods. The MICs values of clotrimazole were 9 E-04-3 E-03 ug/ml, 0.1-0.6 ug/ml, 3 E-03- 0.1 ug/ml and 3 E-03-0.3 ug/ml for Candida albicans susceptible to fluconazole, Candida albicans resistance to fluconazole, Candida krusei and Candida parapsilosis respectively. The MICs values of silver nanoparticles were 26.50- 53 ug/ml; 26.50-106 ug/ml; 106-212 ug/ ml and 26.50- 53 ug/ml for Candida albicans susceptible to fluconazole, Candida albicans resistance to fluconazole, Candida krusei and Candida parapsilosis respectively. Synergism between clotrimazole and silver nanoparticles was measured by checkerboard BMD (broth microdilution) test and shown only for C. albicans susceptible to fluconazole because the fractional inhibitory concentrations (FICs) values were 0.07 - 0.15 ug/ml. Indifference was shown for the other species tested because the FICs values were between 0.5 - 2- 3.06 ug/ml. The results suggest synergistic activity depending on the fungus species analysed, however we recommend the incorporation of others measurement methodologies to confirm our results. As for measurement methodologies of MICs of silver nanoparticles and clotrimazole international normative were respected to guarantee reproducible and comparable results.