Fucoidan-coated cotton dressing functionalized with biomolecules capped silver nanoparticles (LB-Ag NPs-FN-OCG) for rapid healing therapy of infected wounds.

The colonization of pathogenic microbes poses a significant clinical barrier that hinders the physiological wound-healing process. Addressing this challenge, we developed a novel wound dressing using a modified cotton gauze dressing coated with fucoidan and functionalized with silver nanoparticles (LB-Ag NPs-FN-OCG) for the rapid treatment of infected wounds. Firstly, phytochemical-capped LB-Ag NPs were synthesized and characterized using high performance liquid chromatography (HPLC), transmission electron microscopy (TEM), and zeta potential analysis. Secondly, different concentrations of LB-Ag NPs (0.1%-1%) were functionalized into FN-OCG to identify appropriate concentrations that were non-toxic with superior antibacterial activities. Screening assays, including antibacterial, hemolysis, chick chorioallantoic membrane (CAM) assay, and cytotoxicity assay, revealed that LB-Ag NPs (0.5%)-FN-OCG were non-toxic and demonstrated greater efficiency in inhibiting bacterial pathogens (Escherichia coli, Salmonella enterica, Staphylococcus aureus, and Listeria monocytogenes) and promoting fibroblast cell (NIH3T3) migration. In vivo assays revealed that LB-Ag NPs (0.5%)-FN-OCG treatment exhibited excellent wound healing activity (99.73 ± 0.01%) compared to other treatments by inhibiting bacterial colonization, maintaining the blood parameters, developing granulation tissue, new blood vessels, and collagen deposition. Overall, this study highlights that LB-Ag NPs (0.5%)-FN-OCG serve as a antibacterial wound dressing for infected wound healing applications.

Environmental factors modify silver nanoparticles ecotoxicity in Chydorus eurynotus (Cladocera).

Silver nanoparticles (AgNPs) are among the most produced nanomaterials in the world and are incorporated into several products due to their biocide and physicochemical properties. Since freshwater bodies are AgNPs main final sink, several consequences for biota are expected to occur. With the hypothesis that AgNPs can interact with environmental factors, we analyzed their ecotoxicity in combination with humic acids and algae. In addition to the specific AgNPs behavior in the media, we analyzed the mortality, growth, and phototactic behavior of Chydorus eurynotus (Cladocera) as response variables. While algae promoted Ag+ release, humic acids reduced it by adsorption, and their combination resulted in an intermediated Ag+ release. AgNPs affected C. eurynotus survival and growth, but algae and humic acids reduced AgNPs lethality, especially when combined. The humic acids mitigated AgNP effects in C. eurynotus growth, and both factors improved its phototactic behavior. It is essential to deepen the study of the isolated and combined influences of environmental factors on the ecotoxicity of nanoparticles to achieve accurate predictions under realistic exposure scenarios.

Colloidal chitosan-silver nanoparticles-fluoride nanocomposite as an antibacterial mouthwash against salivary Streptococcus mutans in orthodontic patients (a randomized clinical trial).

OBJECTIVES: This study aimed to synthesize and characterize colloidal chitosan-silver nanoparticles-fluoride nanocomposite (CCAgNPF) and evaluate its efficacy compared to chlorhexidine on salivary Streptococcus mutans in orthodontic patients. MATERIALS AND METHODS: AgNPs stabilized with chitosan were synthesized by chemical reduction of AgNO3. The nanoparticles were characterized with SEM, FTIR, DLS and ICP-OES. The MIC and MBC against S. mutans and IC50 concentration of CCAgNPF were obtained for antibacterial and cytotoxicity evaluations, respectively. For the clinical study, a total of 45 orthodontic patients were divided into three groups of 15 and used the following mouthwashes twice a day for 1 month: CCAgNPF, chlorhexidine 0.2% and the combination of these mouthwashes. The colony count of salivary S. mutans was evaluated before and after using the mouthwashes. The data were analyzed using One-way ANOVA and Tukey's test. RESULTS: Stabilized AgNPs were spherical with a diameter of 25.3 ± 3.3 nm. The MIC, MBC and IC50 of CCAgNPF were 4.42, 8.85 and 18.89 µg/ml. All mouthwashes reduced the salivary S. mutans of the orthodontic patients, however, no significant difference was found between the efficacy of CCAgNPF and chlorhexidine (P-value > 0.05). The best results were achieved by the combination of CCAgNPF and chlorhexidine mouthwashes (P-value < 0.05). CONCLUSION: The CCAgNPF and its combination with chlorhexidine present potent bactericidal, biocompatible and effective anti-carious mouthwashes for orthodontic patients. CLINICAL RELEVANCE: This study proved CCAgNPF as an antibacterial mouthwash with lower cytotoxicity and side effects for patients undergoing orthodontic treatments to maintain oral hygiene and reduce salivary S. mutans.

The effect of nano silver fluoride, self-assembling peptide and sodium fluoride varnish on salivary cariogenic bacteria: a randomized controlled clinical trial.

OBJECTIVES: To compare the antibacterial effect of Nanosilver Fluoride varnish (NSF) varnish, P11-4 and Sodium Fluoride (NaF) varnish against salivary Streptococcus mutans (S. mutans) and Lactobacilli. METHODS: 66 patients aged 10-24 years old were randomly assigned to receive single application of NSF, P11-4 or NaF varnish. Baseline unstimulated saliva samples were collected before the agents were applied and S.mutans and Lactobacilli colony forming units (CFU) were counted. After one, three and six months, microbiological samples were re-assessed. Groups were compared at each time point and changes across time were assessed. Multivariable linear regression compared the effect of P11-4 and NSF to NaF on salivary S. mutans and Lactobacilli log count at various follow up periods. RESULTS: There was a significant difference in salivary S. mutans log count after 1 month between P11-4 (B= -1.29, p = 0.049) and NaF but not at other time points nor between NSF and NaF at any time point. The significant reduction in bacterial counts lasted up to one month in all groups, to three months after using P11-4 and NaF and returned to baseline values after six months. CONCLUSION: In general, the antimicrobial effect of P11-4 and NSF on salivary S. mutans and Lactobacilli was not significantly different from NaF varnish. P11-4 induced greater reduction more quickly than the two other agents and NSF antibacterial effect was lost after one month. CLINICAL RELEVANCE: NSF varnish and P11-4 have antimicrobial activity that does not significantly differ from NaF by 3 months. P11-4 has the greatest antibacterial effect after one month with sustained effect till 3 months. The antibacterial effect of NSF lasts for one month. NaF remains effective till 3 months. TRIAL REGISTRATION: This trial was prospectively registered on the clinicaltrials.gov registry with ID: NCT04929509 on 18/6/2021.

Green Method for the Preparation of Durable Superhydrophobic Antimicrobial Polyester Fabrics with Micro-Pleated Structures.

To produce functional protective textiles with minimal environmental footprints, we developed durable superhydrophobic antimicrobial textiles. These textiles are characterized by a micro-pleated structure on polyester fiber surfaces, achieved through a novel plasma impregnation crosslinking process. This process involved the use of water as the dispersion medium, water-soluble nanosilver monomers for antimicrobial efficacy, fluorine-free polydimethylsiloxane (PDMS) for hydrophobicity, and polyester (PET) fabric as the base material. The altered surface properties of these fabrics were extensively analyzed using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectrometry (XPS), thermogravimetric analysis (TGA), and water contact angle (WCA) measurements. The antimicrobial performance of the strains was evaluated using Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. After treatment, the fabrics exhibited enhanced hydrophobic and antimicrobial properties, which was attributed to the presence of a micro-pleated structure and nanosilver. The modified textiles demonstrated a static WCA of approximately 154° and an impressive 99.99% inhibition rate against both test microbes. Notably, the WCA remained above 140° even after 500 washing cycles or 3000 friction cycles.

Escherichia coli isolates from meat and abattoirs environment in Egypt: molecular characterization and control by nanosilver particles.

Three hundred samples, including meat from the slaughtered carcass and water, air samples, and swabs from the floor, wall, and employees' hands, were collected from five municipal abattoirs spread across several Egyptian provinces. The Escherichia coli was isolated from floor swabs, meat, air, wall, hand, and water samples. Serotyping of the recovered isolates clarified the presence of various serotypes, including enterohemorrhagic serotypes (O111: H4, O128: H2, and O127: H6) and enterotoxigenic serotypes (O44: H18 and O125: H21). The isolates were resistant to cefotaxime (100%), amoxiclav (80%), then rifampin (66.7%). The stx1 gene, stx2 gene, eaeA gene, blaCMY2 gene and iss gene were detected in 10-80 % of the isolates. Nanosilver (AgNPs) showed that 12.5 ppm was the lowest concentration that prevented bacterial growth. It was observed that 12% of workers wore a clean white coat, only 24% washed their hands between activities during work, only 14% used soap for hand washing, and 42% utilized the same knife for meat and its offal.

Evaluation of staining potential of Silver Diamine Fluoride, Potassium Iodide, Nanosilver Fluoride: an in vitro study.

BACKGROUND: The black staining effect of silver-containing solutions for use to arrest caries can have a negative aesthetic impact on children and parents. This study aims to assess the staining effects of Silver Diamine Fluoride/Potassium Iodide (SDF/KI), SDF and Nanosilver Fluoride (NSF). MATERIALS AND METHODS: Forty-four extracted carious primary molars were collected and randomly divided into four groups (n = 11). The carious tissue in all teeth was removed using a chemo-mechanical caries removal agent with an excavator. After caries removal in all groups, SDF, SDF/KI, and NSF were applied to the different groups, while no solution was applied to the control group. Subsequently, the teeth in all groups were restored with compomer. Color values L*, a* and b* were measured using a spectrophotometer at three time points: immediately after compomer restoration (T0), one week later (T1), and four week later (T2). Changes in brightness (ΔL) and color (ΔE) over time were calculated and comparisons among groups were made. RESULTS: The SDF solution induced statistically significant black staining (p = 0.013) and a decrease in L* value (p < 0.001) on the compomer material compared to the other groups over time. CONCLUSIONS: It was observed that SDF/KI has the potential to reduce the black staining effect of SDF, though not entirely. Novel experimental solutions like NSF may offer an alternative to counteract the staining effect of SDF.

Benefits and risks of using bacterial- and plant-produced nano-silver for Japanese quail hatching-egg sanitation.

This research compared how bacterial-, plant-produced silver nanoparticles (Ag-NPs) and TH4 affected the eggshells microbial load and quail chicks' liver structure, embryonic mortality, and features related to hatchability. Ag-NPs were sensitized by bacterial and plant methods, and then identified by UV-visible spectroscopy, TEM, and FTIR spectroscopy. B-Ag-NPs were found in spherical shapes in size ranging from 7.09 to 18.1 nm versus multi-shape with size range of 25.0-78.1 nm for P-Ag-NPs. A total number of 624 eggs (in three equal groups) of Japanese quail flock were sprayed with TH4 as control, B-Ag-NPs and P-Ag-NPs. Thereafter, three eggs were sampled randomly from each group for determining important microbial groups. The remaining eggs were incubated according to the recommended incubation conditions. On the day of hatching, the percentages of hatchability and embryonic mortality were measured. Besides, five chicks from each treatment were slaughtered and the livers were utilized for ICP and histological tests. The effects of all three treatments on the microbial count in eggshells were comparable, according to the results. In addition, there was no negative effect on either hatchability percentage or embryonic mortality rate. The liver structure from both B-Ag-NPs and P-Ag-NPs treatments exhibited severe and moderate degeneration of hepatocytes, which may indicate possible hazardous effects of using nanoparticles. Using TH4 did not cause liver structure abnormality. In conclusion, using Ag-NPs for sanitizing hatching eggs effectively reduces the eggshell microbial count without affecting the hatchability percentage. Nevertheless, histological changes are appropriate to be considered as a safety parameter in Ag-NPs applications.

Application of composite antibacterial nanoparticle non-woven fabric in sterilization of hospital infection.

The use of disinfection materials and instruments is an important part of surgical operation. Hospital environment and surgical equipment need comprehensive sterilization treatment. This process is the key to the success of the operation, and it is also one of the first ways to control the hospital to avoid infection during the operation. The selection of scientific and reasonable sterilization methods for infection will directly affect the safety of medical treatment. In order to improve the antibacterial properties of medical non-woven fabrics, this paper combines two antibacterial methods of sterilization and antibacterial adhesion, and uses the principle of nanotechnology to design that the non-woven fabrics have good blood compatibility in the sterilization process. Then, a new composite antibacterial nanoparticle antibacterial solution is prepared from the synthesized nano­silver solution, and the antibacterial solution is attached to the non-woven fabric, so that the nano­silver particles with antibacterial effect are fixed on the surface of the fabric, and its antibacterial effect is measured through the antibacterial test, and excellent hospital infection sterilization technology is prepared and applied to the non-woven fabric products. The fusion experiment of platelets and red blood cells shows that the prepared surface technology combined with antibacterial adhesion and sterilization can effectively fuse with platelets and red blood cells, and can also effectively prevent the adhesion of platelets and red blood cells, and shows good blood compatibility, which is applicable to the sterilization process of hospital infection.

Effect of nanoclay supported nanosilver on the growth inhibition of aquatic pathogens and immunomodulatory effect in Penaeusvannamei.

Hybrid of nanosilver and nanoscale silicate platelet (AgNSP) is a safe, non-toxic nanomaterial which has been applied in medical use due to its strong antibacterial activity. The application of AgNSP in aquaculture was first proposed in the present study by evaluating the in vitro antibacterial activities against four aquatic pathogens, in vitro effects toward shrimp haemocytes as well as the immune responses and disease resistance in Penaeus vannamei fed with AgNSP for 7 days. For evaluating the antibacterial activities of AgNSP in culture medium, the minimum bactericidal concentration (MBC) values against Aeromonas hydrophila, Edwardsiella tarda, Vibrio alginolyticus and Vibrio parahaemolyticus were 100, 15, 625 and 625 mg/L, respectively. Moreover, the inhibition of pathogen growth over a period of 48 h could be achieved by the appropriate treatment of AgNSP in culturing water. In freshwater containing bacterial size of 103 and 106 CFU/mL, the effective doses of AgNSP against A. hydrophila were 12.5 and 450 mg/L, respectively while the effective doses against E. tarda were 0.2 and 50 mg/L, respectively. In seawater with same bacterial size, the effective doses against V. alginolyticus were 150 and 2000 mg/L, respectively while the effective doses against V. parahaemolyticus were 40 and 1500 mg/L, respectively. For the in vitro immune tests, the superoxide anion production and phenoloxidase activity in haemocytes were elevated after in vitro incubation with 0.5-10 mg/L of AgNSP. In the assessment of dietary supplemental effects of AgNSP (2 g/kg), no negative effect on the survival was found at the end of 7 day feeding trail. In addition, the gene expression of superoxide dismutase, lysozyme and glutathione peroxidase were up-regulated in haemocytes taken from shrimps received AgNSP. The following challenge test against Vibrio alginolyticus showed that the survival of shrimp fed with AgNSP was higher than that of shrimp fed with control diet (p = 0.083). Dietary AgNSP improved the Vibrio resistance of shrimp by increasing 22.7% of survival rate. Therefore, AgNSP could potentially be used as a feed additive in shrimp culture.

Porosity effect on the mechanical properties of nano-silver solder.

Nano-silver has the characteristics of low-temperature sintering and high-temperature service, which can reduce the thermal stress in the packaging process. Because of the high melting point and good high-temperature mechanical properties, silver is widely used in high-temperature packaging and connection fields. Sintered nano-silver has a porous structure on the microscopic level, it is necessary to study the mechanical properties of nano-silver with porosity. In this paper, we proposed a method for finite element modeling of porous nano-silver. Finite element analysis and nanoindentation test were used to investigate the Young's modulus of nano-silver. At the same time, and the quadratic equation of porosity and Young's modulus was fitted, and it was verified by Ramakrishnan model and nanoindentation results. These results show that the Young's modulus of nano-silver decreases with the increase of internal porosity, and the Young's modulus and porosity show a quadratic function correlation. As the porosity increases, the Young's modulus of nano-silver decreases at a slower rate. The modeling method presented in this paper can well predict the Young's modulus of nano-silver.

Mechanism of wound repair in diabetic rats using nanosilver-free alginate dressing.

OBJECTIVE: Nanosilver-alginate dressing can effectively promote the healing of diabetic wounds in rats. However, due to the potential toxicity of nanosilver, its widespread application in hard-to-heal wound healing is limited. In the present study, the role and potential mechanism of nanosilver-free alginate gel (NSFAG) in the healing process of diabetic wounds were explored. METHOD: A diabetic rat skin wound model was established, and wounds were treated with saline (NC group), nanosilver gel (NSG group) or nanosilver-free alginate gel (NSFAG group) for seven consecutive days. RESULTS: NSFAG significantly promoted wound healing and increased the content of protein and hydroxyproline in granulation tissues, and was superior to NSG (p<0.05). Immunohistochemical analyses revealed that the skin wound tissue structure of the NSFAG group was intact, and the number of skin appendages in the dermis layer was significantly higher compared with the NC group and the NSG group (p<0.05). Western blot analysis found that the protein expression of the epidermal stem cell marker molecules CK19 and CK14 as well the proliferation marker of keratinocytes Ki67 in the NSFAG group was significantly higher compared with the NC group or NSG group (p<0.05). Additionally, the proliferation marker of keratinocytes Ki67 in the NSFAG group was significantly higher compared with the NC or NSG group (p<0.05). Immunofluorescence staining analyses indicated that the CK19- and CK14-positive cells were mainly distributed around the epidermis and the newly formed appendages in the NSFAG group, and this result was not observed in the NC or NSG groups. CONCLUSION: The present findings demonstrate that NSFAG can effectively accelerate wound healing in diabetic rats by promoting epidermal stem cell proliferation and differentiation into skin cells, as well as formation of granulation tissue, suggesting that it can be a potential dressing for diabetic wounds.

0.1% Nano-silver mediates PD-1/PD-L1 pathway and alleviates chronic apical periodontitis in rats.

This study was to investigate whether the programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) and T-helper 17 (Th17)/regulatory T (Treg) balance are associated with chronic apical periodontitis (CAP) relived by 0.1% nano-silver. CAP rat models were established by opening the first molars of the right and left mandible and exposing the pulp cavity to the oral cavity. CAP model was verified by cone-beam computed tomography, X-ray digital radiovisiography, and hematoxylin-eosin (H and E) staining. The rats were randomly divided into the sham, Ca(OH)2, and 0.1% nano-silver groups (n = 12 in each group) 2 weeks after surgery. The pathological changes in the apical area were detected by H and E staining. PD-1, PD-L1, RORγT, IL-17, and Foxp3 in periapical tissues were detected by qRT-PCR and immunohistochemistry. Th17/Treg and PD-1/PD-L1 were analyzed by flow cytometry. After 7, 14, and 21 days of 0.1% nano-silver treatment, inflammatory cells in the apical region were slightly reduced and inflammatory infiltration was relieved compared with the sham group. RORγT, IL-17, PD-1, and PD-L1 decreased and Foxp3 increased after 7, 14, and 21 days of 0.1% nano-silver treatment compared with the sham group (p < 0.05); however, there were no significant differences with Ca(OH)2 group (p > 0.05). Flow cytometry revealed that 0.1% nano-silver solution decreased Th17/Treg and PD-1/PD-L1 ratio. 0.1% Nano-silver significantly reduced the inflammation of CAP in rats. PD-1/PD-L1 was included in Th17/Treg balance restored by 0.1% nano-silver.

The Preparation of Silver and Gold Nanoparticles in Hyaluronic Acid and the Influence of Low-Pressure Plasma Treatment on Their Physicochemical and Microbiological Properties.

Nanometals constitute a rapidly growing area of research within nanotechnology. Nanosilver and nanogold exhibit significant antimicrobial, antifungal, antiviral, anti-inflammatory, anti-angiogenic, and anticancer properties. The size and shape of nanoparticles are critical for determining their antimicrobial activity. In this study, silver and gold nanoparticles were synthesized within a hyaluronic acid matrix utilizing distilled water and distilled water treated with low-pressure, low-temperature glow plasma in an environment of air and argon. Electron microscopy, UV-Vis and FTIR spectra, water, and mechanical measurements were conducted to investigate the properties of nanometallic composites. This study also examined their microbiological properties. This study demonstrated that the properties of the composites differed depending on the preparation conditions, encompassing physicochemical and microbiological properties. The application of plasma-treated water under both air and argon had a significant effect on the size and distribution of nanometals. Silver nanoparticles were obtained between the range of 5 to 25 nm, while gold nanoparticles varied between 10 to 35 nm. The results indicate that the conditions under which silver and gold nanoparticles are produced have a significant effect on their mechanical and antibacterial properties.

Nutritional and ameliorative effects of dietary curcumin and its nano-silica and nano-zeolite encapsulated forms on growth, biochemical and fatty acid profile of common carp (Cyprinus carpio).

The present study aimed to examine individual nutritional and ameliorative effects of silica nanoparticles (SiO2NPs) and natural zeolite nanoparticles (ZeNPs) and their potential role as carriers to alter the bioavailability of curcumin. Common carps (Cyprinus carpio) were fed during 60 days with a control diet, and curcumin, turmeric, SiO2NPs, curcumin-loaded SiO2NPs, ZeNPs, and curcumin-loaded ZeNPs each at 1, 50, 6.15, 7.15, 39, and 40 g/kg diet, respectively. The highest weight gain (WG) and specific growth rate (SGR) were observed in fish fed with turmeric (P < 0.05). Moreover, dietary curcumin and ZeNPs increased the content of monounsaturated fatty acids (P < 0.05). After exposure to silver nanoparticles (AgNPs), the lowest amount of aspartate aminotransferase (AST) was obtained in fish fed with curcumin (P < 0.05). In addition, alanine aminotransferase (ALT) decreased significantly in the negative control, curcumin, and curcumin-loaded SiO2NPs treatments in comparison to the positive control group (P < 0.05). The lowest silver accumulation was observed in the negative control and SiO2NPs groups (P < 0.05). This experiment demonstrated that while the nanoencapsulation of curcumin on SiO2NPs and ZeNPs did not enhanced the impact of curcumin on the growth and biochemical factors of carps, it can still be considered a potential dietary supplement for enhancing growth and antioxidant indices when added individually to the diet.

Effect of Nano-Silver on Formation of Marine Snow and the Underlying Microbial Mechanism.

Roller experiments were conducted to explore the effect of nano-silver on the formation of marine snow and the underlying microbial mechanism. With the increasing concentration of nano-Ag from 1 ng/L to 1 mg/L, the formation and aggregation of marine snow particles were solidly suppressed in a dose-dependent pattern. Moreover, the formed marine snows tended to be thinner fibrous particles with smaller size and increased edge smoothness and compactness in the presence of nano-Ag. The microbial analyses indicated that nano-Ag not only inhibited the development of biomass but also changed the species composition and functional profile of the microbial community. Nano-Ag obviously inhibited most of the abundant species, except for some myxobacteria, which is unfavorable for the microbial community stability. For the microbial functions, some major biological processes including the growth, metabolic, and cellular processes were also inhibited by the high dosage of nano-Ag. The strong microbial inhibition of nano-Ag would contribute to the suppression on the formation of marine snow. Specifically, the function genes of extracellular polymeric substance synthesis and secretion were significantly reduced by nano-Ag, which might be the key and straight microbial factor in suppressing the formation of marine snow.

Efficacy and safety of chitosan-based bio-compatible dressing versus nanosilver (ActicoatTM ) dressing in treatment of recalcitrant diabetic wounds: A randomized clinical trial.

Chitosan has a biocompatible, biodegradable, and nontoxic nature. The effectiveness of Nano-chitosan films in the field of wound healing has been confirmed previously. The aim of this study was to compare the clinical efficacy and safety of two dressings (chitosan and nanosilver dressings) in the treatment of refractory diabetic wounds. A total of 25 eligible patients with chronic diabetic wound were included and randomly assigned to receive chitosan (13 patients) or nanosilver (12 cases) dressing. The dressings were applied on the wounds based on their protocols and patients were visited and examined by an experienced dermatologist every week. The clinical assessments and healing rates were recorded using diabetic-foot-infection (DFI) score at the 2nd, 4th, and 6th weeks during treatment. The study endpoint, safety and tolerability profile were also documented. The patterns of change in total 10-item-DFI wound scores did not differ significantly over time between the two groups. In both groups, the total 10-item-DFI wound score reduced continuously through the course of study. The mean percentage reduction of this score from baseline was 78.1% and 74.1% in the chitosan and nanosilver dressing groups, respectively. Both dressings were well tolerated and there were no adverse events. The relatively small sample size in both groups was the main limitation of the study. Our findings confirmed that chitosan may be safely and effectively used for the treatment of diabetic wounds just like the nanosilver (ActicoatTM ) dressing. Further studies are recommended with more volunteers and a longer follow-up period.

Effect of Nanosulfur Against Multidrug-Resistant Staphylococcus pseudintermedius and Pseudomonas aeruginosa.

Multidrug resistance (MDR) has significantly increased in the past decades and the use of nanotechnology has opened new venues for novel treatments. Nanosulfur is a potent antimicrobial agent and a cheaper alternative to other nanomaterials. However, very few studies have been published on its activity against MDR organisms. Therefore, the goal of this in vitro study was to assess cytotoxicity, antimicrobial, and anti-biofilm activity of nanosulfur (47 nm, orthorhombic) against clinical isolates of MDR Staphylococcus pseudintermedius (SP) and Pseudomonas aeruginosa (PA) in planktonic and biofilm state using canine skin explants. Nanosilver (50 nm, spherical) was tested as a comparative control. Concentrations between 1866.7 and 0.11 µg/mL of both nanoparticles were tested. The ultrastructure of nanosulfur was assessed via electron microscopy. Both types of nanoparticles showed no direct cytotoxicity on a canine keratinocyte cell line. In the planktonic phase, nanosulfur was able to inhibit or kill (6-log10 reduction of CFU) 7 of 10 MDR-SP isolates at 233.3 µg/mL, whereas, when in biofilm state, 6 of 10 isolates were killed at different concentrations (233.33 to 1866.7 µg/mL). Nanosilver did not show any antimicrobial or anti-biofilm activity at any concentrations tested. Both types of nanoparticles were ineffective against MDR-PA in either state. Ultrastructurally, nanosulfur was present in individual nanoparticles as well as forming larger nanoclusters. This is the first study showing an antimicrobial and anti-biofilm activity of nanosulfur for MDR-SP in absence of cytotoxicity. Nanosulfur has the potential to be used in veterinary and human medicine as effective, safe, and cheap alternative to antimicrobials and anti-biofilm agents currently available. KEY POINTS: • Nanosulfur is a better alternative than nanosilver to treat MDR-Staphylococci. • Nanosulfur is an effective agent against MDR-Staphyloccocal biofilm. • Canine skin explant model is reliable for testing anti-biofilm agents.

SERS- and absorbance-based catalytic assay for determination of isocarbophos using aptamer-modified FeMOF nanozyme and in situ generated silver nanoparticles.

A new Fe metal-organic framework-loaded liquid crystal 4-octoxybenzoic acid (FeMOF@OCTB) nanosol was synthesized using 1,3,5-phthalic acid, ferrous sulfate, and OCTB as precursors. The FeMOF@OCTB exhibits good stability and strong catalytic effect for the polyethylene glycol 400-Ag (I) indicator reaction, which was evaluated rapidly by the slope procedure. The generated silver nanoparticles have a strong surface-enhanced Raman scattering (SERS) effect and a surface plasmon resonance absorption (Abs) peak at 420 nm. This new bimodal nanosilver indicator reaction was coupled with the isocarbophos (IPS)-aptamer (Apt) reaction. A FeMOF@OCTB nanocatalytic amplified-SERS/Abs bimodal Apt assay for IPS was established. The SERS assay can detect IPS in the concentration range 0.02-1.2 nM, with a detection limit of 0.010 nM. It has been applied to the determination of IPS in rice samples. The relative standard deviation was 4.4-5.8%, and the recovery was 97.7-104%. An Ag nanosol plasmon SERS/Abs dimode aptamer assay was fabricated for trace isocarbophos, based on highly catalysis MOF@OCTB nanoenzyme.

The antibacterial effect and the incidence of post-operative pain after the application of nano-based intracanal medications during endodontic retreatment: a randomized controlled clinical trial.

OBJECTIVE: This clinical trial aimed to evaluate the effect of nano-silver and nano-calcium hydroxide intracanal medicaments (ICM) during retreatment regarding their antibacterial effect and their effect on post-operative pain and flare-ups. MATERIALS AND METHODS: Sixty-nine patients scheduled for endodontic retreatment were included in this randomized clinical trial and randomly allocated to 3 equal groups (n = 23) according to the type of ICM used. The first microbial sampling (S1) representing the original microbiota was obtained after the removal of the old canal filling. After chemo-mechanical debridement, another sample (S2) was obtained representing the microbial state before ICM application. Patients were randomly allocated to receive either nano-silver (nano-Ag), nano-calcium hydroxide (nano-CH), or calcium hydroxide (CH) as ICM. Patients rated their pain pre-operatively and then after 6, 12, 24, 48, and 72 h. During the second visit (7 days later), the last microbial sample (S3) was obtained after removal of the ICM. Reduction of total bacterial and total E. faecalis counts and the biofilm-forming capability of the existing microbiota were determined. RESULTS: Results showed reduction in total bacterial count, total E. faecalis count and the biofilm-forming,capability of the existing microbiota after chemo-mechanical debridement (S1-S2) and after the application of ICM (S3-S2). However, the reduction after cleaning and shaping was significantly more pronounced (p < 0.001) compared to the effect of ICM application, with no difference between the 3 ICM (p > 0.05). Post-operative pain was significantly reduced at the 48- and 72-h intervals after the application of nano-Ag and nano-CH only (p < 0.001), with no significant difference between these two ICM (p > 0.05). The incidence of flare-ups in all groups was similar (p > 0.05). CONCLUSIONS: The antibacterial effect of the nano-Ag and nano-CH was equivalent to that of CH, but they contributed to better pain control. CLINICAL RELEVANCE: Nanoparticles may have a positive impact on post-endodontic pain.