OBJECTIVE: To explore the preparation of nano-silver acupuncture needles and evaluate the appearance, structure and properties. METHODS: Stainless steel acupuncture needles were pretreated by polishing with sandpaper and cleaning with ultrapure water and absolute ethanol. As the working electrodes, the needles were placed in an electrolyte solution contained silver nitrate (AgNO₃), potassium nitrate (KNO₃), and polyvinylpyrrolidone (PVP); and the silver nanoparticles were deposited at a constant voltage of -0.2 V for 1 200 s. The heat-treatment was conducted at 600 ℃ for 15 min in an argon atmosphere to strengthen the adhesion between the nanoparticles and the substrate. The surface appearance and structure of nano-silver acupuncture needles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The electrical conductivity, thermal conductivity and biocompatibility of the needles were evaluated. The cytotoxicity and biocompatibility of the sample were assessed using the CCK-8 assay. According to the national standard, Acupuncture Needles (GB 2024-2016), the other physicochemical performances of nano-silver acupuncture needles were tested. RESULTS: ①By controlling the AgNO₃ concentration and the molar ratio of AgNO₃ to PVP, it was found that at an AgNO₃ concentration of 2 mmol/L and a molar ratio of 5∶1, silver nanoparticles with the diameter of 50-100 nm, regular appearance, and uniform distribution were obtained. At a lower concentration, the size of silver nanoparticles was smaller and unevenly distributed particles, whereas a higher concentration tended to produce a dendritic structure. ②By sandpaper polishing, acid etching pretreatment, and heat-treatment at 600 ℃ under argon for 15 min, the adhesion of silver nanoparticles on the surface of the needle body was strengthened, and the simulated pig skin puncture test showed the intact coating without shedding. ③SEM found that the silver nanoparticles were uniformly deposited, forming a nanofilm approximately 1.5 μm thick; XRD analysis showed the diffraction peaks corresponding to cubic crystal silver (111), (200), (220) and (311); and XPS detected characteristic peaks of Ag 3d3/2 and Ag 3d5/2, confirming the successful deposition and good crystallinity of the silver nanoparticles. ④Resistivity measurements indicated that the nano-silver acupuncture needles exhibited a resistivity of approximately 0.15 Ω·cm, about three times lower than that of unmodified stainless steel needles. The infrared thermography demonstrated that their thermal conductivity was superior to that of traditional acupuncture needles. In vitro CCK-8 cytotoxicity assay showed that the nano-silver acupuncture needles had no adverse effects on human skin fibroblasts and possessed good biocompatibility. ⑤ The key parameters such as needle tip performance, hardness, and the adhesion between the needle body and handle were in compliance with the requirements in Acupuncture Needles (GB 2024-2016), ensuring a quality guarantee provided for clinical applications. CONCLUSION The preparation of nano-silver acupuncture needles effectively overcomes the insufficient toughness of traditional silver needles and improves the electrical and thermal conductivity of stainless acupuncture needles.
Silver/chemistry* ; Needles ; Acupuncture Therapy/instrumentation* ; Metal Nanoparticles/chemistry* ; Humans ; Electric Conductivity ; Animals

OBJECTIVE: To characterize the silver in chitosan antibacterial gel, and to establish a method for the determination of silver content in samples. METHODS: The silver in the samples was analysed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and single particle inductively coupled plasma mass spectrometry (SP-ICP-MS). Microwave digestion was adopted to digest the chitosan antibacterial gel, and then the content of silver was determined by flame atomic absorption spectrometry. RESULTS: The analysises showed that the particle size of silver in chitosan antibacterial gel was about 150~ 200 nm. The silver showed good linearity in the concentration range of 25~250 μg/L (y=0.000 35x+0.001 7, r=0.999 9). The recovery rate (n=9) was 98.5%. CONCLUSIONS SEM, EDS and SP-ICP-MS can be used for the characterization of silver particles in chitosan antibacterial gel. Microwave digestion-flame atomic absorption spectrophotometry method is simple, practicable, high precision and high quantitative accuracy, which is suitable for the quantitative analysis of silver in chitosan antibacterial gel.
Anti-Bacterial Agents/pharmacology* ; Chitosan/chemistry* ; Microwaves ; Particle Size ; Silver

Using three-dimensional printing to produce antibacterial wound dressing is a new topic that will change the production style of wound dressing industry. Combining with post-3D-printed process, a desktop fused deposition molding equipment can be used to produce wound dressing containing polyvinyl alcohol, alginate and chitosan. The wound dressing produced by FDM has good aspects of absorbency, moisture vapour transmission rate and mechanical property. After loaded with antibacterial agent iodine and silver nano particle, the antibacterial activity rate increases to 99% and it is suitable to use as antibacterial wound dressing. This method affects the production of wound dressing to a more cost-effective way, and provides a possible individualized treatment for patient in the future.
Alginates ; chemistry ; Anti-Bacterial Agents ; administration & dosage ; Bacteria ; drug effects ; Bandages ; economics ; standards ; Chitosan ; chemistry ; Humans ; Iodine ; administration & dosage ; pharmacology ; Nanoparticles ; administration & dosage ; Polyvinyl Alcohol ; chemistry ; Printing, Three-Dimensional ; Silver ; administration & dosage ; pharmacology ; Wound Healing

Biosynthesis of silver and other metallic nanoparticles is one of the emerging research area in the field of science and technology due to their potentiality, especially in the field of nano-biotechnology and biomedical sciences in order to develop nanomedicine. In our present study, Penicillium decumbens (MTCC-2494) was brought from Institute of Microbial Technology (IMTECH) Chandigarh and employed for extracellular biological synthesis of silver nanoparticles. Ag-NPs formation was appeared with a dark brown color inside the conical flask. Characterization of Ag-NPs were done by UV-Spectrophotometric analysis which showed absorption peak at 430 nm determines the presence of nanoparticles, Fourier transform infrared (FT-IR) spectroscopic analysis, showed amines and amides are the possible proteins involved in the stabilization of nanoparticles as capping agent. Atomic force Microscopy (AFM) confirmed the particle are spherical, size was around 30 to 60 nm and also the roughness of nanoparticles. Field emission scanning electron microscopy (FE-SEM) showed the topology of the nanoparticles and were spherical in shape. The biosynthesis process was found fast, ecofriendly and cost effective. Nano-silver particle was found to have a broad antimicrobial activity and also it showed good enhancement of antimicrobial activity of Carbenicillin, Piperacillin, Cefixime, Amoxicillin, Ofloxacin and Sparfloxacin in a synergistic mode. These Ag-NPs showed good anti-cancer activity at 80 μg·mL(-1)upon 24 hours of incubation and toxicity increases upon 48 hours of incubation against A-549 human lung cancer cell line and the synergistic formulation of the antibiotic with the synthesized nanoparticles was found more effective against the pathogenic bacteria studied.
Anti-Bacterial Agents ; metabolism ; pharmacology ; Antineoplastic Agents ; metabolism ; pharmacology ; Bacteria ; drug effects ; Cell Line, Tumor ; Humans ; Lung Neoplasms ; drug therapy ; Metal Nanoparticles ; chemistry ; Microbial Sensitivity Tests ; Penicillium ; metabolism ; Silver ; metabolism ; pharmacology

Silver nanoparticles (AgNPs) have been widely used in industrial, household, and healthcare-related products due to their excellent antimicrobial activity. With increased exposure of AgNPs to human beings, the risk of safety has attracted much attention from the public and scientists. In review of recent studies, we discuss the potential impact of AgNPs on individuals at the cell level. In detail, we highlight the main effects mediated by AgNPs on the cell, such as cell uptake and intracellular distribution, cytotoxicity, genotoxicity, and immunological responses, as well as some of the major factors that influence these effects in vivo and in vivo, such as dose, time, size, shape, surface chemistry, and cell type. At the end, we summarize the main influences on the cell and indicate the challenges in this field, which may be helpful for assessing the risk of AgNPs in future.
Chemistry ; Family Characteristics ; Humans ; Nanoparticles* ; Risk Assessment ; Silver*

Silver nanoparticles were synthesized from the extract of Fagopyri Dibotryis Rhizoma and the optimization of synthesis was studied. The absorbance of UV-visible spectroscopy was determined under the different influencing factors such as extracting time of Fagopyri Dibotryis Rhizoma powder, reation temperature of synthesis, volume of Fagopyri Dibotryis Rhizoma extract and concentration of AgNO3 to seek the optimization conditions. By means of FT-IR, TEM, DLS and XRD, the silver nanoparticles were characterized. The results showed that when the boiling time of Fagopyri Dibotryis Rhizoma powder was 5 min, resultant temperature was 25 degrees C, the volume ratio of 0.1 g x mL(-1) Fagopyri Dibotryis Rhizoma extract and 1 mmol x L(-1) AgNO3 was 1 to 10, and the reaction time was 3.5 h, the obtained silver nanoparticles had mean size about 27 nm and Zeta potential about -34.3 mV with good uniformity and dispersivity. Therefore, the green synthesis method of silver nanoparticles using extract of traditional Chinese medicine is stable and feasible.
Fagopyrum ; chemistry ; Light ; Metal Nanoparticles ; chemistry ; ultrastructure ; Microscopy, Electron, Transmission ; Particle Size ; Plant Extracts ; chemistry ; Rhizome ; chemistry ; Scattering, Radiation ; Silver ; chemistry ; Silver Nitrate ; chemistry ; Spectroscopy, Fourier Transform Infrared ; Temperature ; X-Ray Diffraction

This research was aimed to find the skin irritation and burns treatment effect of wound dressing with mi- crospheres containing levofloxacin. We used reference GB/T16886. 10-2005 to evaluate the dressing skin irritation. We prepared rabbit models divided into three groups. The control group was rapped with Vaseline gauze bandage, while the positive control group was rapped with the wounds of nano-silver paste bandage. The experimental sample group was rapped with wound dressing with microspheres containing levofloxacin. We measured the wound without healing area and the hydroxyproline content at the ends of 3 d, 6 d, 9 d, 14 d, 21 d, 28 d. and meanwhile performed histopathological examination. The experimental results showed that the dressing primary irritation index was 0. The nonhealing wound area of theexperimental sample group and positive control group at the ends of 6 d, 9 d, 14 d, 21 d were less than that of the control group (P<0. 05). The nonhealing wound area of the experimental sample group at the ends of 9 d and 14 d was significantly lower than that of the positive control group (P < 0.05). The hydroxyproline content of the experimental sample group at the ends of 6 d, 9 d and 14 d was significantly higher than that of the positive control group and blank control group (P<0. 05). The pathology observed of the experimental sample group at 21 d were the earliest appendages. The wound dressing with microspheres containing levofloxacin has minimal skin irritation, effectively promote wound healing of burn.
Animals ; Bandages ; Burns ; therapy ; Hydroxyproline ; chemistry ; Levofloxacin ; therapeutic use ; Microspheres ; Rabbits ; Silver ; Wound Healing

We prepared silver nanoparticles/polyethyleneimine-reduction graphene oxide (AgNP/rGO-PEI) composite materials, and evaluated their quality performance in our center. Firstly, we prepared AgNP/rGO-PEI, and then analysed its stability, antibacterial activity, and cellular toxicity by comparing the AgNP/rGO-PEI with the silver nanoparticles (PVP/AgNP) modified by polyvinylpyrrolidone. We found in the study that silver nanoparticles (AgNP) distributed relatively uniformly in AgNP/rGO-PEI surface, silver nanoparticles mass fraction was 4.5%, and particle size was 6-13 nm. In dark or in low illumination light intensity of 3 000 lx meter environment (lux) for 10 days, PVP/AgNP aggregation was more obvious, but the AgNP/rGO-PEI had good dispersibility and its aggregation was not obvious; AgNP/rGO-PEI had a more excellent antibacterial activity, biological compatibility and relatively low biological toxicity. It was concluded that AgNP/rGO-PEI composite materials had reliable quality and good performance, and would have broad application prospects in the future.
Anti-Bacterial Agents ; chemistry ; Graphite ; chemistry ; Light ; Nanoparticles ; chemistry ; Oxides ; chemistry ; Particle Size ; Polyethyleneimine ; chemistry ; Silver Compounds ; chemistry

Silver nanoparticles are considered as good antimicrobial agent. AgNPs were synthesized by mixing silver nitrate solution with citrus sinesis extract for 2 h at 37 °C and analyzed by UV-visible spectra, SEM, XRD, and FTIR. AgNPs were tested against B. subtilis, Shigella, S. aureus, and E. coli. Minimum inhibitory concentration of AgNPs was 20 µg/mL for B. subtilis and Shigella and 30 µg/mL for S. aureus and E. coli. Antibiofilm activity (80% to 90%) was observed at 25 µg/mL. AgNPs were stable for five months with sustained antimicrobial activity. Biosynthesized AgNPs can be used to inhibit food poisoning microbial growth.
Anti-Bacterial Agents ; pharmacology ; Bacillus subtilis ; drug effects ; Bacteria ; drug effects ; Citrus sinensis ; chemistry ; Escherichia coli ; drug effects ; Foodborne Diseases ; prevention & control ; Metal Nanoparticles ; analysis ; Plant Extracts ; pharmacology ; Shigella ; drug effects ; Silver ; pharmacology ; Staphylococcus aureus ; drug effects

OBJECTIVES: In this study, we investigated the influence of ionic strength and natural organic matter (NOM) on aggregation and soil adsorption of citrate-coated silver nanoparticles (AgNPs). METHODS: Time-resolved dynamic light scattering measurements and batch adsorption experiments were used to study their aggregation and soil adsorption behaviors, respectively. RESULTS: The aggregation rate of AgNPs increased with increasing ionic strength and decreasing NOM concentration. At higher ionic strength, the AgNPs were unstable, and thus tended to be adsorbed to the soil, while increased NOM concentration hindered soil adsorption. To understand the varying behaviors of AgNPs depending on the environmental factors, particle zeta potentials were also measured as a function of ionic strength and NOM concentration. The magnitude of particle zeta potential became more negative with decreasing ionic strength and increasing NOM concentration. These results imply that the aggregation and soil adsorption behavior of AgNPs were mainly controlled by electrical double-layer repulsion consistent with the Derjaguin-Landau-Verwey-Overbeek theory. CONCLUSIONS: This study found that the aggregation and soil adsorption behavior of AgNPs are closely associated with environmental factors such as ionic strength and NOM and suggested that assessing the environmental fate and transport of nanoparticles requires a thorough understanding of particle-particle interaction mechanisms.
Adsorption* ; Chemistry* ; Nanoparticles* ; Osmolar Concentration ; Silver* ; Soil* ; Water*