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Background Silver nanoparticles (AgNPs) are an important class of nanomaterials used as antimicrobial agents for a wide range of medical and industrial applications. However toxicity of AgNPs and impact of their physicochemical characteristics in in vivo models still need to be comprehensively characterized. The aim of this study was to investigate the effect of size and coating on tissue distribution and toxicity of AgNPs after intravenous administration in mice, and compare the results with those obtained after silver acetate administration. Methods Male CD-1(ICR) mice were intravenously injected with AgNPs of different sizes (10 nm, 40 nm, 100 nm), citrate-or polyvinylpyrrolidone-coated, at a single dose of 10 mg/kg bw. An equivalent dose of silver ions was administered as silver acetate. Mice were euthanized 24 h after the treatment, and silver quantification by ICP-MS and histopathology were performed on spleen, liver, lungs, kidneys, brain, and blood. Results For all particle sizes, regardless of their coating, the highest silver concentrations were found in the spleen and liver, followed by lung, kidney, and brain. Silver concentrations were significantly higher in the spleen, lung, kidney, brain, and blood of mice treated with 10 nm AgNPs than those treated with larger particles. Relevant toxic effects (midzonal hepatocellular necrosis, gall bladder hemorrhage) were found in mice treated with 10 nm AgNPs, while in mice treated with 40 nm and 100 nm AgNPs lesions were milder or negligible, respectively. In mice treated with silver acetate, silver concentrations were significantly lower in the spleen and lung, and higher in the kidney than in mice treated with 10 nm AgNPs, and a different target organ of toxicity was identified (kidney). Conclusions Administration of the smallest (10 nm) nanoparticles resulted in enhanced silver tissue distribution and overt hepatobiliary toxicity compared to larger ones (40 and 100 nm), while coating had no relevant impact. Distinct patterns of tissue distribution and toxicity were observed after silver acetate administration. It is concluded that if AgNPs become systemically available, they behave differently from ionic silver, exerting distinct and size-dependent effects, strictly related to the nanoparticulate form.

Background The study investigated the distribution of silver after 28 days repeated oral administration of silver nanoparticles (AgNPs) and silver acetate (AgAc) to rats. Oral administration is a relevant route of exposure because of the use of silver nanoparticles in products related to food and food contact materials. Results AgNPs were synthesized with a size distribution of 14 ± 4 nm in diameter (90% of the nanoparticle volume) and stabilized in aqueous suspension by the polymer polyvinylpyrrolidone (PVP). The AgNPs remained stable throughout the duration of the 28-day oral toxicity study in rats. The organ distribution pattern of silver following administration of AgNPs and AgAc was similar. However the absolute silver concentrations in tissues were lower following oral exposure to AgNPs. This was in agreement with an indication of a higher fecal excretion following administration of AgNPs. Besides the intestinal system, the largest silver concentrations were detected in the liver and kidneys. Silver was also found in the lungs and brain. Autometallographic (AMG) staining revealed a similar cellular localization of silver in ileum, liver, and kidney tissue in rats exposed to AgNPs or AgAc. Using transmission electron microscopy (TEM), nanosized granules were detected in the ileum of animals exposed to AgNPs or AgAc and were mainly located in the basal lamina of the ileal epithelium and in lysosomes of macrophages within the lamina propria. Using energy dispersive x-ray spectroscopy it was shown that the granules in lysosomes consisted of silver, selenium, and sulfur for both AgNP and AgAc exposed rats. The diameter of the deposited granules was in the same size range as that of the administered AgNPs. No silver granules were detected by TEM in the liver. Conclusions The results of the present study demonstrate that the organ distribution of silver was similar when AgNPs or AgAc were administered orally to rats. The presence of silver granules containing selenium and sulfur in the intestinal wall of rats exposed to either of the silver forms suggests a common mechanism of their formation. Additional studies however, are needed to gain further insight into the underlying mechanisms of the granule formation, and to clarify whether AgNPs dissolve in the gastrointestinal system and/or become absorbed and translocate as intact nanoparticles to organs and tissues.

Introduction Mechanical ventilation is a significant risk factor for developing ventilator‐associated pneumonia. Although silver‐coated endotracheal tubes have been shown to reduce the bacterial burden, the efficacy of silver‐based ion additive ventilator circuits in reducing bacterial colonization remains unclear. Methods This single‐site, randomized controlled trial compared the incidence of bacterial contamination between a silver‐additive ventilator circuit and a ventilator circuit that did not have a silver additive. Bacterial samples were collected from the inspiratory limb and Y‐adaptor of the circuit and analyzed using culture and identification methods. Results Bacterial growth was observed in all samples from the control group and in 93.7% and 81.2% of inspiratory limb and Y‐adaptor samples, respectively, from the study group. The colony counts in the inspiratory limb samples were significantly different between the groups, with a higher proportion of undesirable colony counts in the control group compared with the study group. No significant difference between the groups was observed in the colony counts in the Y‐adaptor samples. Conclusion The use of a silver‐additive ventilator circuit may reduce bacterial circuit colonization. However, further research with larger sample sizes and more diverse patient populations is necessary to confirm these findings. Trial Registration: ClinicalTrial.gov: NCT04927806 Configuration of ventilator system and sampling site. (A) Inlet tube of heated humidifier. (B) Inspiratory limb. (C) Y‐adaptor. HEPA: high‐efficiency particulate air.

Background Intertrigo is often underdiagnosed in obesity. Objectives To investigate the incidence of intertrigo in obesity and assess the efficacy of a moisture‐wicking fabric (MWF) with antimicrobial silver. Methods Intertrigo symptoms were evaluated in patients with severe obesity, and the effect of MWF application was assessed in a subset of these patients after 5 or 10 days of use. Results In inpatients with obesity (n = 2.778, mean age 63.9 ± 13.3 years, BMI 43.4 ± 6.8 kg/m2), intertrigo lesions were found in 15.9% under the breast (37.4%), abdomen (19.0%), and inguinal area (9.6%). It was more prevalent in women (12.3%), especially among patients older than 65 years (50.9%), with a mean BMI of 46.4 ± 7.3 kg/m2, waist circumference of 129.6 ± 15.2 cm, and mean fat mass of 51.1% ± 6.2%. A subset of 40 patients with intertrigo was randomly divided into two groups: one treated with MWF (mean age 57.0 ± 14.2 years, BMI 46.4 ± 8.2 kg/m2) and the other with traditional treatment (mean age 62.0 ± 14.1 years, BMI 49.9 ± 7.5 kg/m2). The MWF treatment resulted in significantly faster symptom resolution (6.0 ± 2.4 days for MWF vs. 11.0 ± 3.9 days in control group; p < 0.001). Conclusions We underline the need for intertrigo screening in patients with obesity, especially in those with risk factors, such as female, older, and higher BMI. The use of a novel MWF effectively alleviates symptoms within a short treatment period and should be considered as an optional intertrigo treatment.

Silver nanoparticles (AgNPs) have recently emerged as a powerful agents for disinfection in the poultry industry. AgNPs are capable of epithelial barriers passing from the route of exposure to the vital organs and cells. This study evaluated the effects of AgNPs on organs weights, blood biochemical, hematological, and coagulation parameters, antioxidant enzyme activities, and histopathological changes and silver concentrations of liver and kidney tissues in laying Japanese quails after exposure to the nanoparticles. The layer quails were randomly assigned to 4 groups, consisting of six replicates, three quails each. The treatments included 0, 4, 8, and 12 mg/L of AgNPs in daily drinking water for 30 weeks. AgNPs decreased the relative weight of liver, ileum and large intestine (P < 0.05). Administration of AgNPs elevated plasma fibrinogen while decreased serum aspartate aminotransferase activity (P < 0.05). The antioxidant status of the liver showed that malondialdehyde level, an end product of lipid peroxidation, was higher (P < 0.05) and catalase activity was lower (P < 0.05) in the quails exposed to AgNPs. The accumulation of silver in the liver and kidney tissues were increased in a dose-dependent manner after exposure to AgNPs (P < 0.05). Histopathological findings showed reduced lipid vacuolization of hepatocytes in the 12 mg/L AgNPs treatment. In conclusion, the results indicated that AgNPs administration to drinking water can lead to oxidative stress and liver damage in laying quails which may be a predisposing for liver dysfunction.

The aim of this study was to evaluate the abatement power of oral microbial loading of a new gel formulation based on the complex silver-2-mercaptobenzoate, chlorhexidine digluconate and didecyldimethylammonium chloride (named ADC) through polymerase chain reaction (PCR). The study sample consists of a group of 20 patients with chronic periodontal disease. Patients were over 25 years of age and did not undergo surgical or non-surgical periodontal treatment in the previous 6 months. The study sample was allotted into two groups of 10 patients each, homogeneous by age and sex. The test group received a bottle containing ADC gel, while the control group received an identical one containing placebo, similar to ADC in consistence, colour, taste and odour. Sub-gingival samples of four sites, one in each quadrant, of greatest probing depth in each patient were used. Microbiological analyses were performed at baseline and at day 15. Paired t test was performed to detect statistical significant reduction in total bacterial loading and oral pathogens in the study groups. The analysis showed a statistically significant reduction in the total bacterial loading evaluated pre- and post-treatment (P = 0.029) in the study groups. In the control group, the decrease in total bacterial loading was not significant (P = 0.279). Clinically, ADC gel does not have any side effects and discomfort such as pain, burning, tingling sensation or numbness and produces no adverse reactions in time. Our study aimed to evaluate the efficacy of a new chemical formulation with antibacterial properties to use for daily oral hygiene with a preliminary study. Our results showed a statistically significant reduction in total bacterial loading after treatment, but the limitations of our study do not allow us to demonstrate the clinical efficacy of the ADC gel.

The aim of the study was to examine the mean mineral density (MD) change in early proximal enamel caries lesions after applying silver diamine fluoride (SDF) using digital subtraction radiographic analysis at 6 and 12 months. A split-mouth, triple-blind, randomized controlled trial was conducted with thirty healthy participants aged 13–30 years old. Two active non-cavitated proximal caries lesions in different quadrants of each participant were randomly sampled and allocated to a test (38% SDF) and a control group (deionized water). Digital radiographs at baseline, 6 and 12 months were taken, and digital subtraction radiographic analysis was performed. The SDF group demonstrated a significantly higher mean MD on subtraction radiographs compared with the control group, after adjusting for baseline lesion depth and time, and for clustering within participants over time. The adjusted mean difference was 1.0 [95% CI 0.2, 1.9]. Therefore, applying SDF at baseline and 6 months resulted in significant remineralization compared with the control group over the 12-month period. These findings suggested that applying SDF can serve as an effective alternative treatment option for remineralizing early caries lesions on proximal surfaces.

Background Silver diamine fluoride (SDF) is a simple and non-invasive agent used to arrest early childhood caries (ECC). This study aimed to investigate potential changes to the oral microbiome in children with ECC who were treated with SDF and sodium fluoride (NaF) varnish at three different frequency regimens. Methods Forty-five children ( n  = 15 per group) with ECC were recruited from community-based dental clinics in Winnipeg, Canada into an open-label, parallel-group, randomized clinical trial testing three different treatment frequency regimens of SDF. A total of 195 carious lesions were treated with two applications of 38% SDF and 5% NaF varnish (and assessed over three study visits one month, four months, or six months apart. Dental plaque samples were collected at each visit. Sequencing of the V4-16 S rRNA and ITS1 rRNA genes were used to study the supragingival plaque microbiome. Results Microbial diversity analyses showed no significant differences in the overall microbiome after SDF treatment. However, significant changes in the abundance of specific bacteria and fungi, particularly Lactobacillus spp., Bifidobacterium spp., and Candida spp., were observed after treatment. Furthermore, overabundance of Streptococcus mutans and Candida dubliniensis at baseline was observed in children who had at least one caries lesion not arrested after one SDF application, compared to those who had 100% arrest rates. The overall arrest rates for treated carious lesions were 75.9% at the second visit and 92.8% at the third visit. Arrest rates were higher for all lesions after two applications of SDF with NaF varnish, and applications one month and four months apart had higher arrest rates (95.9% and 98.5%) than six months (81.1%) apart. Conclusions Applications of SDF with NaF varnish were an effective modality for arresting ECC, with higher arrest rates after two SDF applications. No loss of diversity but changes in the abundance of specific bacteria and fungi were observed after SDF treatment. Trial registration ClinicalTrials.gove NCT04054635 (first registered 13/08/2019).

The indications for collagenase ointment (CO) and its efficacy are not clearly established in the treatment of second-degree burn wounds. To evaluate the efficacy of CO versus silver sulfadiazine ointment (SSD) in the treatment of second-degree burn wounds. A total of 170 eligible patients with deep second-degree burns, aged 18–65 years, with injuries occurring within 48–96 h, and having a total wound area of less than 30% of the total body surface area were included from 5 centers in China. The primary outcome was the wound healing time, and the secondary outcomes were the clearance time of wound necrotic tissues, wound healing rate, and wound inflammation. The study included 85 patients in SSD group and 84 in CO group in the modified intention-to-treat (mITT) population. The median time of wound healing was comparable in both groups (10 days vs. 10.5 days P  = 0.16). The time for wound necrotic tissue removal was significantly shortened by CO compared with SSD (5 vs. 10 days P  < 0.01). Wound inflammation, pain, wound healing rate, and scar were compared with SSD (all P-values > 0.05). No adverse events, such as infection or allergic reactions to the drugs and materials used, were reported. Both CO and SSD could heal the burn wounds at 10 days of treatment. However, CO significantly shortened the time of wound necrotic tissue removal by 5 days. Trial Registration: ChiCTR2100046971.

The aim of this prospective multicenter randomized controlled trial was to compare the efficacy of silver nitrate cauterization against that of topical steroid ointment in the treatment of neonatal umbilical granuloma. An open-label, non-inferiority randomized controlled trial was conducted from January 2013 to January 2016. The primary endpoint for the silver nitrate cauterization and topical steroid ointment groups was the healing rate after 2 weeks of treatment, applying a non-inferiority margin of 10%. The healing rate was evaluated until completion of 3 weeks of treatment. Participants comprised 207 neonates with newly diagnosed umbilical granuloma, randomized to receive silver nitrate cauterization (n = 104) or topical steroid ointment (n = 103). Healing rates after 2 weeks of treatment were 87.5% (91/104) in the silver nitrate cauterization and 82% (82/100) in the topical steroid ointment group group. The difference between groups was -5.5% (95% confidence interval, -19.1%, 8.4%), indicating that the non-inferiority criterion was not met. After 3 weeks of treatment, the healing rate with topical steroid ointment treatment was almost identical to that of silver nitrate cauterization (94/104 [90.4%] vs. 91/100 [91.0%]; 0.6% [-13.2 to 14.3]). No major complications occurred in either group. This study did not establish non-inferiority of topical steroid ointment treatment relative to silver nitrate cauterization, presumably due to lower healing rates than expected leading to an underpowered trial. However, considering that silver nitrate cauterization carries a distinct risk of chemical burns and that the overall efficacy of topical steroid ointment treatment is similar to that of silver nitrate cauterization, topical steroid ointment might be considered as a good alternative in the treatment of neonatal umbilical granuloma due to its safety and simplicity. To clarify non-inferiority, a larger study is needed.