AgNPs Group Research Articles

Raptinal silver nanoparticles: new therapeutic advances in hepatocellular carcinoma mouse model.

Raptinal is a novel antineoplastic agent that induces an expeditious intrinsic apoptotic pathway, in addition to the shutdown of mitochondrial function for cancerous cells, because of silver nanoparticles (AgNPs) that have been shown to provide a worthy approach to overcome tumors. In this study, Both Raptinal and Raptinal-loaded silver nanoparticles (AgNPs) were tested as the first time in hepatocellular carcinoma-induced mice to evaluate its efficacy and targeting to HCC. Seventy-two albino male mice of comparable age were classified into six groups; early stage of HCC was induced using diethyl nitrosamine (DEN)/carbon tetrachloride (CCL4). Liver function was assessed in all groups using ALT, AST, total bilirubin, and alpha-fetoprotein (AFP) as well as histopathological examination. Quantitative gene expression of key apoptotic gene markers p53, cytochrome c, and caspase 3 was assessed in all liver homogenates. The results showed that Raptinal-loaded AgNPs group had significant increase in both apoptotic genes of cytochrome c and Caspase 3 at P = 0.0001 compared with Raptinal-free drug group. AFP levels were significantly decreased in Raptinal-loaded AgNPs group compared with both Raptinal-free drug and HCC groups at P = 0.0001. Degenerative changes in the hepatocytes with focal necrosis and inflammatory cell infiltration in histopathology confirm the biochemical analysis. Our study is considered one of the first studies using Raptinal in vivo. Moreover, it showed that Raptinal and/or the combination between Raptinal and AgNPs showed a promising therapeutic agent in treating early HCC.

Synthesis of green nanobiofertilizer using silver nanoparticles of Allium cepa extract Short title: Green nanofertilizer from Allium cepa

The present study involved the green synthesis of onion silver nanoparticles (AgNPs) from the onion extract as a reducing agent to develop nanobiofertilizer. Characterization of AgNPs was done by Fourier transform infrared (FTIR) spectroscopy, UV-Visible spectrophotometer and Scanning Electron Microscopy (SEM). UV–vis spectroscopy confirmed the formation of AgNPs by observing the typical surface plasmon resonance peak at 470 nm. The possible functional groups of AgNPs were identified by FTIR analysis. SEM studies revealed that AgNPs were cubical shaped with an average particle size range from 10 to 30 nm. The both the fresh weight and vigor were higher in plants treated with 15 ml/l synthesized nanobiofertilizer compared to control. The synthesized nanobiofertilizer from onion extract is an effective fertilizer for brinjal and tomato plants. The use of such types of nanobiofertilizer can reduce the excessive use of chemical fertilizers, environmental pollution and helps in reduction of farm management costs.

Evaluation of the toxic effect of silver nanoparticles and the possible protective effect of ascorbic acid on the parotid glands of albino rats: An in vivo study

This study aimed to evaluate the toxic effect of silver nanoparticles (AgNPs) on the parotid glands (PGs) of albino rats histologically and ultrastructurally and assess the possible protective effect of ascorbic acid as an antioxidant. Thirty male albino rats weighing between 150 mg and 200 mg were divided into three groups: the control group (C1) contained 10 rats that received 2 mg/kg (body weight (bw)) of aqueous nitrate buffer by intraperitoneal (IP) injection daily for 28 days; the AgNPs group contained 10 rats that received 2 mg/kg (bw) IP AgNPs daily for 28 days; and the AgNPs-vitamin C group contained 10 albino rats that received 2 mg/kg (bw) AgNPs IP daily for 28 days with oral administration of 100 mg/kg (bw) vitamin C in drinking water daily for 28 days. The PG acinar and ductal cells of the AgNPs group showed signs of toxicity and degeneration characterized as pleomorphic nuclei, binucleation, cytoplasmic vacuolations, and stagnated secretion in the ductal lumen. In addition to degenerated mitochondria, dilated rough endoplasmic reticulum and lysosomes were filled with AgNPs (p < 0.001). The AgNPs-vitamin C group showed significantly less degenerative changes histologically and ultrastructurally compared to the AgNPs group (p = 0.002). AgNPs produced significant toxic effects on the PG of albino rats, presumably through the generation of reactive oxygen species and toxic ion release, and administration of vitamin C was shown effective in decreasing these toxic effects.

The Effect of Silver Nanoparticles on the Healing Process of Excisional Skin Wounds in Adult Albino Rats: Histological and Immunohistochemical Study

Abstract Background The ultimate goal for wound healing is a speedy recovery with minimal scarring. Different approaches have been used for achieving this goal such as antimicrobials and cell growth promoting agents. Recently, silver nanoparticles (AgNps) have become of interest in biomedical applications, because of their antibacterial, antifungal, antiviral and anti-inflammatory activity. Aim was to investigate the role of AgNps on the healing process of excisional skin wounds in adult male albino rats. Material &amp; Methods 72 male albino rats weighing 200 g were obtained from research center, Ain Shams Faculty of Medicine and subjected to excisional skin wounds 1.5 cm in diameter on their mid-backs. Then rats were divided into 4 groups 18 rats each; control (group I) skin wounds were left to heal naturally. Other wounds were topically treated once daily with methylcellulose hydrogel (group II), silver sulphadiazine (group III), and AgNps in methylcellulose hydrogel (group IV). For each group 6 rats were sacrificed on each of the following days post-wounding; 3rd, 7th and 14th. Skin specimens from all groups were fixed in 10% neutral formalin &amp; processed for paraffin sections which were stained with Hx &amp; E, Mallory’s Trichrome and vascular endothelial growth factor (VEGF). Using image analysis software, number of (macrophages, newly formed blood vessels &amp; fibroblasts) and area % of collagen fibers deposition were assessed and statistically analyzed. Results Control and methylcellulose hydrogel groups revealed almost similar results. Re-epithelialization started on day 3 post-wounding only in AgNps treated group and on day 7 in all other groups. Epithelialization was complete on day 14 only in AgNps treated group and the dermis was mostly regenerated with the appearance of skin appendages. Components of the granulation tissue varied considerably among the studied groups and across the three time points. In Hx &amp; E stained sections the number of macrophages was highest in AgNps treated group on day 3 post-wounding then was the lowest on days 7 and 14 compared with other groups as confirmed by image analysis. Neovascularization started on day 3 in all groups but was prominent on AgNps treated group which showed high density on day 7 as proved statistically and by results of VEGF immune staining. The number of the newly formed blood vessels declined on day 14 in AgNps treated group and remained high in silver sulphadiazine group and showed maximum density in control groups. Statistical analysis proved that the number of fibroblasts in AgNps group was maximum on day 7 &amp; decreased to minimum on day 14 compared with all other groups. In Mallory’s trichrome stained sections the area percent of collagen fibers deposition in the granulation tissue was maximum in AgNps treated group across all periods of the study compared to other studied groups. Conclusion AgNps showed advantage of rapid healing of excisional skin wounds in rats compared with traditional methods of treatment. It might be the treatment of choice particularly for high risk patients.

The effect of Silver Nanoparticle Induced Diabetic on Wound Healing Full Thickness Pseudomonas aeruginosa Contaminated Mouse Skin Wound Models

This research was considered to evaluate the antidiabetic effect of silver nanoparticle (AgNps)and following experimental diabetic. In the present study. Thirty healthy swiss mice aged between 7-8 weeks, old male mice and divided into six groups of five animals. Diabetic induced mice by using intraperitoneal (IP) injection of alloxan (180 mg lkg). Group 1 included non diabetic control, Group 2 Diabetic, Group 3 Diabetic +0.01 mg AgNps Group 4 Diabetic +0.05 AgNps, Group 5 Diabetic+ wound contaminated with Pseudomonas aeruginosa. Group 6 ( diabetic +contaminated wound + silver nanoparticle (Ag Nps). Silver nanoparticle show ample antibacterial activities. The result of the current study introduced an invivo silvernanoparticle accelerate by effects on the treatment of Pseudomonas aeruginosa infected skin wound. The present study was conducted to synthesis the AgNps biologically and evaluate its antibacterial activity against Pseudomonas aeruginosa diabetes induced by Alloxan in mice. Adminstration of silver nanoparticle resulted in significance antidiabetic effects that is is improved glucose tolerance higher source. The current study results are presented for the first time which suggest for the development of AgNps as anantdiabetic factor in future. The broad spectrum of bioactivity of AgNPs makes them promising agent not only to fight infection, but to sterile the wound and accelerate wound healing. There were significant higher wound healing scores in Nanoparticle treated group. Compared with control group. These result suggest that nanoparticle may be useful in diabetic wound healing. Treatment with asingle dose of AGNPs produced amild reduction in blood glucose and some reduction in plasma insulin at 2 h.The present results revealed the potential of the synthesized Ag-NPs as safer bactericidal agents for the treatment of diabetes induced wound contaminated with P.aeruginosa.

Stretchable multifunctional dielectric nanocomposites based on polydimethylsiloxane mixed with metal nanoparticles

Next generation wearable electronics require stretchable dielectrics. There has been significant effort to characterize and improve the components of dielectric composites for use in these devices. In this work, a new stretchable dielectric material, composited by silver nanoparticles (Ag NPs), nickel nanoparticles (Ni NPs), and polydimethylsiloxane (PDMS), is prepared and characterized. The alternating arrays of Ag NPs groups and Ni NPs groups in the three-dimensional matrix of PDMS function as micro capacitors and prevent current percolation. Compared with PDMS alone, the alternating arrays exhibit a dielectric constant (k) that is increased by 1146% and can reach 35.13, with dielectric loss as low as 0.009. Slightly lower k and larger dielectric loss appear at high frequencies. The material exhibits negative temperature dependence, and the composition ratio affects the dielectric properties. The strain at break is 139.68% and the elastic modulus is as low as 3.57 kPa. By controlling the type, size and dispersion of metal nanoparticles in PDMS matrix, a parallel-plate capacitor with constant capacitance is achieved, demonstrating the dependence of the dielectric constant on the applied strain. Moreover, by replacing the parallel plates with cylindrical fibers, a capacitive strain sensor was demonstrated. After hundreds of stretching-releasing cycles, the dielectrics work normally. The excellent properties of this material suggest its significant potential for use in wearable electronics.

Assessment of cytotoxicity and antibacterial effects of silver nanoparticle-doped titanium alloy surfaces

ObjectivesThis study aimed to develop silver nanoparticle (AgNP)-doped Ti6Al4V alloy surfaces and investigate their antibacterial properties against representative periopathogens and potential cytotoxicity on osteoblastic cells. MethodsAgNPs of different size distributions (5 and 30nm) were incorporated onto the Ti6Al4V surfaces by electrochemical deposition, using colloid silver dispersions with increasing AgNP concentrations (100, 200 and 300ppm). The time-course silver release from the specimen surfaces to cell culture media was assessed by Atomic Absorption Spectroscopy (AAS). Cell attachment, viability and proliferation were investigated by SEM, live/dead staining MTT and BrdU assays. The antibacterial effects were assessed against P. gingivalis and P. intermedia by serial dilution spotting assays. ResultsA time- and concentration-dependent silver release from the experimental surfaces was observed. Overall, cell viability and attachment on the AgNP-doped surfaces, suggested adequate cytocompatibility at all concentrations. A transient cytotoxic effect was detected at 24h for the 5nm-sized groups that fully recovered at later time-points, while no cytotoxicity was observed for the 30nm-sized groups. A statistically significant, concentration-dependent decrease in cell proliferation rates was induced at 48h in all AgNP groups, followed by recovery at 72h in the groups coated with 5nm-sized AgNPs. A statistically significant, concentration-dependent antibacterial effect up to 30% was confirmed against both periopathogens. SignificanceThis study sheds light to the optimal size-related concentrations of AgNP-doped Ti6Al4V surfaces to achieve antibacterial effects, without subsequent cytotoxicity. These results significantly contribute to the development of antibacterial surfaces for application in oral implantology.

Developing biocompatible silver nanoparticles using epigallocatechin gallate for dental use

ObjectiveTo develop silver nanoparticles (AgNPs) using epigallocatechin gallate (EGCG) and evaluate its biocompatibility and inhibition effect on Streptococcus mutans biofilm growth. DesignAgNPs were synthesized using EGCG as a reducing agent. Cytotoxicity was assessed using half-maximal inhibitory concentration (IC50) against human gingival fibroblast (HGF-1) and stem cells from human exfoliated deciduous teeth (SHED). Antibacterial properties were evaluated with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against S. mutans. Dentine blocks were treated with AgNPs, silver nitrate (AgNO3), or water before being incubated with S. mutans. The kinetics, morphology and viability of the biofilm at different time points were assessed by colony-forming units (CFUs), scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM), respectively. Lactic acid and polysaccharide production of the biofilm were also investigated. ResultsSpherical AgNPs with diameter 17 ± 7 nm were developed. The IC50 of AgNPs and AgNO3 against HGF-1 were 44.88 ± 11.39 μg/mL and 11.53 ± 6.96 μg/mL, respectively (p < 0.001), whereas those against SHED were 68.02 ± 24.48 μg/mL and 9.54 ± 6.63 μg/mL, respectively (p = 0.02). The MIC of AgNPs and AgNO3 were 32.22 ± 7.34 μg/mL and 48.89 ± 15.11 μg/mL, respectively (p = 0.01), whereas their MBC was 63.33 ± 11.73 μg/mL and 85.00 ± 20.77 μg/mL, respectively (p = 0.02). Log CFUs of the AgNPs group were the lowest among the groups (p < 0.001). SEM and CLSM found a confluent biofilm in AgNO3 and water groups but not in AgNPs group. Biofilms in AgNPs group was revealed with lowest level of acidic acid and polysaccharides production (p < 0.001). ConclusionThis study developed biocompatible AgNPs which inhibited the growth of a cariogenic biofilm.

Intra-canal medication containing silver nanoparticle versus calcium hydroxide in reducing postoperative pain: A randomized clinical trial

Background: Pain of endodontic origin can be annoying for patients and endodontist. Pain relief is more important to the patient than treatment success. Numerous factors such as over instrumentation, over filling, debris extrusion can cause postoperative pain. However, bacteria found in the root canal space is the most important factor. Therefore mechanical preparation is an important step in elimination of micro-organisms from the root canal. It has been reported that micro-organisms can still survive inside the root canal even after mechanical preparation. Hence, the use of intra-canal medicaments in between visits for reduction of bacteria inside the root canal space has been recommended. The aim of this study was to assess the ability of silver nanoparticles versus calcium hydroxide used as intra-canal medication in reducing pain in necrotic teeth with apical periodontitis. Methods: Thirty-four participants were randomly divided into 2 groups, 17 in each group according to intra-canal medication used silver nanoparticles and calcium hydroxide (AgNPs and Ca(OH)2). Each patient was given pain scale chart numerical rating scale (NRS) in order to record his/her pain level before any intervention followed by placement of intra-canal medicament for 1 week. Postoperative pain was recorded at 4, 12, 24, 48 hours. Results: Pre-operatively; there was no statistically significant difference between mean pain scores in the two groups. After 4, 12 as well as 24 hours, Ca(OH)2 group showed statistically significantly higher mean pain score than AgNPs group. After 48 hours; there was no statistically significant difference between mean pain scores in the two groups. Conclusions: There was a statistically significant difference in postoperative pain following 4, 12, and 24 hours where AgNPs group resulted in reduction of pain more than Ca(OH)2 group. At 48 hours, there was no statistically significant difference. Trial registration: PACTR PACTR201602001444180 26/01/2016

Influence of Silver Nanoparticles on the Specific Properties of Acrylic Resin for Ocular Prosthesis

Scleral acrylic resin is widely used to synthesize ocular prosthesis. However, the properties of this material change over time, thus requiring the prosthesis to be refabricated. Many studies were conducted to improve these properties by reinforcing this material with nanoparticles. This study aims to evaluate the effect of silver nanoparticle powder on the mechanical properties (transverse flexural strength, impact strength, shear bond strength, surface microhardness, and surface roughness) of scleral acrylic resin used for ocular prostheses. Two concentrations were selected from the pilot study and evaluated for their effects on scleral acrylic resin properties. According to the pilot study, 0.01 and 0.02wt% AgNPs powder improved the transverse flexural strength, microhardness, and surface roughness compared with other percentages. The specimens in the main study were divided into (3) main groups, (50) specimens without additives (control group A), (50) experimental specimens (with 0.01wt% AgNPs group B), and (50) experimental specimens (with 0.02 wt% AgNPs group C). Each group was subdivided into (5) equal subgroups depending on the tests used. The data were studied using one way ANOVA and post hoc LSD test. At 0.01 wt% AgNPs addition, the mean values of transverse flexural strength insignificantly increased (p&gt; 0.05), and those of impact strength and shear bond strength significantly increased (p&lt; 0.05) compared with those of the control group. At 0.02 wt% AgNPs addition (group C), the mean value of transverse flexural strength significantly increased (p&lt; 0.05), that of impact strength insignificantly increased (p&gt; 0.05), and that of shear bond strength increased with high significance (p&lt; 0.01) compared with those of the control group. Group C showed insignificant increase in the mean values of transverse flexural strength, impact strength, and shear bond strength (p. 0.05) compared with group B. The scleral acrylic resin added with 0.01 and 0.02 wt% AgNPs showed insignificant increase in microhardness and insignificant decrease in surface roughness. The addition of AgNPs powder in both concentrations improved the mechanical properties of scleral acrylic resin used for ocular prostheses.

Combined effect of silver nanoparticles and honey in experimental wound healing process in rats

Background: Wounds are still major problem in developing countries, and may impose severe complications and high cost for therapy. Hence, wound management still remains an important focus of researches. Plastic catheters coated with SNPs prevent biofilm formation. Papaya possesses antibacterial activity which might prevent the multiplication of wound infection causing bacteria. The objective of this study was to combined effect of honey and silver nanoparticles increases the rate of healing in wounds infected by Pseudomonas aeruginosa. Material and Methods: Eighteen healthy adult male Wistar albino rats weighing 250-300 g were used in this study. Excision wound model was used for this study. A wound of 500 mm2 was created using a sterile scalpel by removing the skin on the dorsum of the abdomen of the all group. Clinical assessments included observations concerning the appearance, and the wound size was measured. Results: The wound in all the three groups were almost same in the beginning. The percentage of wound closure on the fifth day was 0.86 ± 0.11, 0.91 ± 0.18 and 0.95 ± 0.07, On d 10 still better wound closure was observed with a percentage there was a significant increase in healing and the percentage closure was 0.76 ± 0.20, 70.2 ± 0.19 and 71.15 ± 0.18 (P<0.001), on d 15 the wound closure percentage was 20.18 ± 0.18, 89.21 ± 0.18 and 94. 31 ± 0.20 (P<0.001), for control, honey treated and honey ± Ag Nps groups respectively with a high significance from control. Conclusion: This study demonstrated the efficacy of multifloral honey mixed with silver nanoparticles in wound healing. Topical application of multifloral honey with silver nanoparticles accelerated the rate of wound healing by increasing the wound contraction compared with honey. The acceleration of wound healing rate and wound contraction through macroscopic and histological evolution on d 1, 5, 10 and 15. Hence, honey mixed with silver nanoparticles is potentially useful in dressing wounds.

Comparative evaluation of antibacterial effect of nanoparticles and lasers against Endodontic Microbiota: An in vitro study.

BackgroundPresent study was conducted with the aim of evaluating antimicrobial efficacy of silver (AgNP) and gold nanoparticles (AuNP) with and without Nd: YAG laser (L) irradiation against experimentally inoculated Enterococcus faecalis in infected human root dentin.Material and Methods120 extracted single rooted human teeth were prepared and inoculated with E. faecalis for 24 hrs. The teeth were then randomly divided into 4 experimental group: AgNPs group: irrigation for 3minutes with 50 μl of 100 ppm, the AuNPs group: irrigation with 50 μl of 100 ppm, the AgNPs & Nd: YAG lasers group: irrigation with 50 μl of 100 ppm + irradiation with 1.5W laser for 60 seconds, the AuNPs & Nd: YAG lasers group: irrigation with 50 μl of 100 ppm + irradiation with 1.5W laser for 60 seconds. One control group consisting of 2% CHX irrigation for 3 minutes was also there (n = 20). The specimens were collected from the canal before and after irrigation, and colony forming units were observed.ResultsSignificant difference was found among all the groups in comparison to the control group (p<0.05). The greatest reduction in CFU’s was observed with combination of AgNPs & Nd: YAG lasers group.Conclusions AgNPs in combination with Nd: YAG laser irradiation has the potential to be used as root canal disinfectant. Key words:Antibacterial efficacy, gold, silver, nanoparticles, lasers, solid-state.

Extracorporeal magnetic approach to reduce the unwanted side-effects and improve antibacterial activity of Ag/Fe3 O4 nanocomposites in rat.

While Ag nanoparticles hold great promise for broad spectrum antibacterial activity, the potential risks of Ag nanoparticles (NPs) on human health remain a challenge. In this study, Ag/Fe3 O4 composites have been successfully prepared and characterized by transmission electron microscopy, X-ray powder diffraction, and Fourier-transform infrared spectroscopy, and their magnetic and antibacterial properties have been assessed. In vivo results show that the antibacterial effect of 500 μg/mL Ag/Fe3 O4 nanocomposites was significantly higher than that of 1000 μg/mL AgNPs after 72 h of treatment (p < 0.01). Hematoxylin and eosin (HE) staining showed that squamous epithelium and dermis collagen fibers formed in the Ag/Fe3 O4 group after 8 days treatment. Wound closure was significantly better for the Ag/Fe3 O4 group than for the AgNPs group. On the other hand, there was less Ag in blood, liver, and kidney in the Ag/Fe3 O4 group, as more Ag was retained in the wound. According to lactate dehydrogenase, γ-glutamyl transpeptidase, and reactive oxygen species results, Ag/Fe3 O4 nanocomposites caused less unwanted side-effects. This work presents a new paradigm to reduce the unwanted side-effects of AgNPs and improve their antibacterial activity, providing a new avenue for wound healing. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2029-2036, 2018.

The interactive effects of diclofop-methyl and silver nanoparticles on Arabidopsis thaliana: Growth, photosynthesis and antioxidant system

Diclofop-methyl (DM), a common post-emergence herbicide, is frequently used in agricultural production. Silver nanoparticles (AgNPs) are one of the most widely used nanoparticles, and as such, have been detected and monitored in several environmental systems. Here we investigated the interactive effects of DM and AgNPs on the physiological morphology, photosynthesis and antioxidant system of Arabidopsis thaliana. Our results demonstrated that a 1.0 mg/L DM treatment had no significant effect on the fresh weight of plant shoots and the content of total chlorophyll and anthocyanin. However, a 0.5 mg/L AgNPs treatment was found to significantly inhibit plant growth and chlorophyll synthesis, and was found to cause more severe oxidative damage in plants compared to the effects observed in a hydroponic suspension in which DM and AgNPs were jointly present. Meanwhile, the relative transcript levels of photosynthesis related genes (psbA, rbcL, pgrl1A and pgrl1B) in the combined group were found to be slightly increased compared to transcript levels in the AgNPs group, in order to maintain ATP generation at relatively normal levels in order to repair light damage. One explanation for these observed antagonistic effects was that the existence of DM affects the stability of AgNPs and reduced Ag+ release from AgNPs in the mixed solution. Thereupon, the Ag+-content was found to decrease in shoots and roots in the combined group by 15.2% and 9.4% respectively, compared to the AgNPs group. The coexistence of herbicides and nanomaterials in aquatic environments or soil systems will continue to exist due to their wide usages. Our current study highlights that the antagonistic effects between DM and AgNPs exerted a positive impact on A. thaliana growth.

The Effect of Silver Nanoparticles on Wounds Contaminated with Pseudomonas aeruginosa in Mice: An Experimental Study.

The microorganisms have been usually noted as the major cause of delayed wound healing. Pseudomonas aeruginosa is the most common pathogen causing these infections. Silver nanoparticles (AgNPs) show ample antibacterial activities. In present study, the effect of AgNPs alone and in combination with tetracycline investigated on inoculated wounds with Pseudomonas aeruginosa in mice. Twenty mice anesthetized and full-thickness skin wounds created on back of them and the bacterial suspension added to each wound bed. Wound infection assessed using total count of bacterial load and also wound healing monitored, macroscopically. In all groups treatments applied topically in the wound bed: AgNPs, tetracycline, AgNPs along with tetracycline and normal saline in control group. The tetracycline along with AgNPs achieved 100% wound closure on day 12. In the AgNPs group, the percentage of wound contraction has close figures compared to tetracycline and normal saline as 98, 99 and 79 percent, respectively. By day 12, all of the treated groups with AgNPs, tetracycline and AgNPs along with tetracycline showed decreases in surface bacterial concentration compared with control group. Also, significant decrease (P < 0.001) in deep skin bacterial counts in the AgNPs, tetracycline and AgNPs along with tetracycline compared with control group at any time point. Application of AgNPs along with tetracycline is more effective than AgNPs and tetracycline alone to reduce the bacterial load whilst wound macroscopic contraction increased. These findings support use of the AgNPs in combination with antibacterial medicine for the treatment of infectious skin wounds.

Antimicrobial, antioxidant and antitumor activities of silver nanoparticles synthesized by Allium cepa extract: A green approach.

An economic and efficient method for the synthesis of silver nanoparticles (AgNPs) was performed using onion (Allium cepa) extract as reducing and capping agent. UV–vis spectroscopy confirmed the formation of silver nanoparticles by observing the typical surface plasmon resonance peak at 420 nm. Transmission electron microscopy studies revealed that AgNPs were spherical in shape with a size range of 10–23 nm. AgNPs were further demonstrated by the characteristic peaks observed in the XRD image. The possible functional groups of AgNPs were identified by FTIR analysis. AgNPs exhibited potential antimicrobial activity against all the microbial strains tested. Antioxidant activity of AgNPs revealed that they can be used as potential radical scavenger against deleterious damages caused by the free radicals. Additionally, AgNPs had antitumor activities against human breast (MCF-7), hepatocellular (HepG-2) and colon (HCT-116) carcinoma cell lines in a dose-dependent manner with IC50 of 1.6, 2.3 and 2.2 μg/ml, respectively. The overall results indicate promising baseline information for the potential uses of AgNPs in the treatment of infectious diseases and tumors.

TOXICOLOGICAL AND HISTOLOGICAL EFFECTS OF SILVER NANOPARTICLES ON THE LUNG OF ADULT MALE ALBINO RAT AND PROTECTIVE ROLE OF GREEN TEA EXTRACT

Silver nanoparticles (AgNPs) are incorporated into a large number of consumer and medical products. AgNPs has been reported as the materials with high toxicity especially after the systemic uses. The present work aimed to evaluate the toxic effects of two different doses 0.5, 10 mg/kg of AgNPs (35±8.5nm) on the lung of adult male albino rat following 30 days oral administration and also to assess the protective role of green tea extract (GT). Sixty rats were classified into six groups (ten rats/ group); Group1:(control group) allowed distillate water, Group2: Rats were given GT at a concentration of 1.5%, Group3: AgNPs treated rats (0.5mg/kg/day), Group4: AgNPs treated rats (0.5mg/kg/day)–co administered GT, Group5: AgNPs treated rats (10mg/kg/day), and Group6: AgNPs (10mg/kg/ day)–co administered GT. This aim was undertaken through adopting certain parameters including, animal observation, changes in body weight, and biochemical studies for antioxidant enzymes {super oxide dismutase (SOD) and catalase (CAT)}. Absolute and relative lung weights have been carried as well. Histological examination of lung tissue using different stains; HE whereas a nonsignificant increase in GT group and groups treated with GT+ AgNPs at the end of experiment as compared to the initial value. AgNPs significantly decreased (CAT) while, increased SOD level. GT significantly increased relative lung weight while, a nonsignificant increase in AgNPs groups as compared to control. Histological examination of lung tissue revealed histological alterations in groups treated with AgNPs which were more pronounced in high dose (10mg) including; thickening of the alveolar wall, destruction of the alveoli, dilated alveoli, mononuclear cellular infiltration associated with marked collagen deposition and weak immunoexpression for surfactant protein B. Coadministration of GT with AgNPs caused significant amelioration of biochemical, histological and immunohistochemical changes induced by AgNPs. Conclusion: Silver nanoparticles caused oxidative damage, biochemical changes and histological alterations in the lung of male rat. This study demonstrates the benefits of green tea as it reduces oxidative damage by virtue of its antioxidant properties thus improving the structural integrity of lung tissue and eventually alleviates the histological changes as well as the biochemical perturbations.

Vitis vinifera Assisted Silver Nanoparticles with Antibacterial and Antiproliferative Activity against Ehrlich Ascites Carcinoma Cells

Vitis vinifera extract assisted silver nanoparticles (AgNPs) were biosynthesized that was confirmed primarily by color change and a sharp plasmon absorption band was found at 449 nm. Biosynthesized AgNPs shape was spherical and the particle size of 17 nm in average was confirmed by transmission electron microscopy (TEM) images. Functional groups of AgNPs were identified by Fourier transform infrared spectroscopy (FTIR). Streptococcus aureus was the most sensitive bacteria towards the assisted V. vinifera AgNPs as their growth was 90% inhibited at 100 μg/mL concentration. That was also confirmed by the zone of inhibition study. Up to 96 h, no biofilm was observed for K. pneumoniae at 40 μg/mL of AgNPs. Although AgNPs showed a mild toxicity against brine shrimp nauplii, it showed a remarkable level of antiproliferative activity against Ehrlich ascites carcinoma (EAC) cells.

Silver and titanium dioxide nanoparticles alter oxidative/inflammatory response and renin–angiotensin system in brain

The study was designed to examine the effects of silver AgNPs, 20 nm) and titanium dioxide (Aeroxide® P25 TiO2NPs, 21 nm) nanoparticles on brain oxidative stress parameters, its antioxidant potential and brain renin–angiotensin system (RAS) in vivo. The analysis was performed 28 days after single dose injection of TiO2NPs and AgNPs (10 or 5 mg/kg body weight, respectively). The AgNPs, but not TiO2NPs, administration resulted in decreased lipid and cholesterol peroxidation. Antioxidant enzymes gene expression and/or activity were changed differently for TiO2NPs and AgNPs group. The TiO2NPs decreased aromatase gene expression, and glutathione peroxidase and reductase activities. In AgNPs group the sodium dismutase 1 and glutathione reductase mRNA levels were decreased as opposed to their activities. Both NPs altered the expression of brain RAS genes (angiotensinogen, renin, angiotensin I converting enzyme 1 and 2), but only TiO2NPs caused similar changes on protein level. The expression of amyloid beta precursor protein gene was not altered by any kind of injected NPs. The TiO2NPs were more potent modulator of gene expression in the brain than AgNPs, despite the two times lower dosage. These results suggest that AgNPs and TiO2NPs exposure may modulate the brain function, but with different strength.

The effect of silver nanoparticles on apoptosis and dark neuron production in rat hippocampus.

Silver nanoparticles (Ag-NPs) are used widely in bedding, water purification, tooth paste and toys. These nanoparticles can enter into the body and move into the hippocampus. The aim of this study was to investigate the neurotoxicity of silver nanoparticles in the adult rat hippocampus. 12 male Wistar rats were randomly divided into two experimental and control groups (6 rats in each group). Animals in the experimental group received Ag-NPs (30 mg/kg) orally (gavage) for 28 consecutive days. Control group in the same period was treated with distilled water via gavage. At the end of experiment, animals were deeply anesthetized, sacrificed, and their brains were collected from each group. Finally the brain sections were stained using toluidine blue and TUNEL. Then to compare the groups, dark neurons (DNs) and apoptotic neurons were counted by morphometric method. Results showed that the numbers of DNs and apoptotic cells in the CA1, CA2, CA3, and dentate gyrus (DG) of hippocampus significantly increased in the Ag-NPs group in comparison to the control group (P<0.05). Exposure to Ag-NPs can induce dark neuron and apoptotic cells in the hippocampus.