Fabrication and Physicochemical Investigation of Ancient Iranian and Pakistani Treated Silver Particles and their Comparison with Silver Nanoparticles.

Silver compounds are known to be both toxic and carcinogenic. However, silver nanoparticles have been showed diagnostic and therapeutic value. They can be used as biological tags for a quantitative detection and/or be incorporated into wound dressings and cosmetics due to their antibacterial properties. Pakistani and Iranian traditional physicians still take the advantage of silver compounds, called silver Kushta, to treat dementia, leprosy, and skin cancers. The present study compared the physicochemical properties of silver nanoparticles (AgNPs) and silver Kushtas (Pakistani silver Kushta (PKAg) and Iranian silver) in terms of the morphology, silver content, chemical composition, and suspension stability. AgNPs were produced through a chemical reduction method using AgNO3 and NaBH4 at 4 °C. PKAg powder was purchased from Hamdard pharmaceutical company (Pakistan). IKAg powder was produced, using closed reactor (Aghili method). Physicochemical properties of all three compounds were examined by scanning electron microscopy, dynamic light scattering, Fourier transform infrared, UV spectra Analysis, Energy Dispersive X-ray analysis, and X-ray diffraction. AgNPs were spherical-shaped and uniform in size. However, PKAg and IKAg particles show different sizes. Not only AgNPs but also IKAg & PKAg Particle sizes were less than 200 nm. According to EDX analysis, the silver contents of PKAg, IKAg, and were 66.24%, 50.43%, respectively. AgNPs, IKAg, and PKAg showed zeta potential values equal to -18.5 and -2.27, and -12 mV, successively. AgNPs, IKAg and PKAg sizes were 64.08, 190.4 and 51.72 nm, respectively. Moreover, XRD results indicated that the composition of IKAg and PKAg are completely different.

Biological Synthesis of Selenium Nanoparticles and Evaluation of their Bioavailability

ABSTRACT Nanoparticles due to their unique properties have attracted more attention and their bacterial biosynthesis is more favorable because is environmental friendly and the size and yield of nanoparticles can be optimized. The aim of the present study was biosynthesis of Selenium nanoparticles using Bacillus cereus. For this purpose, bacterial culture was prepared in the presence of sodium selenate solution and incubated (30°C, 24 h). The produced nanoparticles were purified through consequent centrifugation, washing with 0.9% NaCl, sonication, washing with Tris- HCl containing Sodium dodecyl sulfate (SDS) and finally isolation with water- octanol two phase systems. Then using Ultraviolet-Visible spectroscopy, dynamic light scattering (DLS), scaning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, nanoparticle production was confirmed. The bioavailability of nanoparticles was also investigated in rat. As a result of this study spherical selenium nanoparticles with a mean diameter of 170 nm were biosynthesized. MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) of selenium for Bacillus cereus were same and equal to 75mM. Absorption and secretion of nanoselenium was significantly higher than bulk Selenium (P<0.05). In conclusion in the present study without any chemical substance, spherical Selenium nanoparticles were produced that do not have any environmental contamination. Furthermore, the metabolism of these particles suggests higher absorption rate of them that facilitates its application in medicine and also veterinary medicine.

Optimization of particle size and encapsulation efficiency of vancomycin nanoparticles by response surface methodology.

CONTEXT: Treating vancomycin-resistant Staphylococcus aureus strains requires high doses of vancomycin, which might lead to adverse reactions such as nephrotoxicity and "red neck syndrome". Use of nanotechnology for antibiotic delivery is a promising approach to overcome antibiotic-resistance. OBJECTIVE: The objective of this study was optimizing the particle size and encapsulation efficiency (EE) of vancomycin nanoparticles prepared from chitosan. MATERIALS AND METHODS: The nanoparticles were prepared by ionotropic gelation method, at different combinations of chitosan concentration, chitosan/tripolyphosphate mass and vancomycin/chitosan mass, using Box-Behnken experimental design. Dynamic light scattering and ultracentrifugation were used to measure the nanoparticle size and EE, respectively. Vancomycin was quantified in samples by spectrophotometery. The optimum conditions were determined by subsequent regression analysis and multicriteria decision analysis of the output data. RESULTS: The nanoparticle size and EE were greatly influenced by the independent variables, which had interactive effects on both responses. The optimum conditions for production of nanoparticles were chitosan concentration of 0.5-1.2 mg/ml, chitosan/tripolyphosphate mass ratio of 3-3.5 and vancomycin/chitosan mass ratio of 1, which yielded nanoparticles between 130 and 150 nm with encapsulation efficiencies of 60-69%. CONCLUSIONS: The size and EE of vancomycin nanoparticles were optimized by the proposed procedure.

Optimization of size and encapsulation efficiency of 5-FU loaded chitosan nanoparticles by response surface methodology.

The objective of this study was to optimize the particle size and encapsulation efficiency of chitosan nanoparticles loaded with 5-Fluorouracil (5-FU) by response surface methodology. Nanoparticles were prepared by ionic gelation method from chitosan and penta sodium triphosphate (TPP) at different combinations of chitosan viscosity, chitosan concentration and chitosan/TPP mass ratio according to the Box-Behnken experimental design. The particle size and encapsulation efficiency of prepared particles were measured by dynamic light scattering and UV spectroscopy, respectively, and the obtained data were subjected to multiple linear regression analysis followed by multi-attribute utility analysis to obtain a model for prediction of the optimum response. The optimum conditions for the production of 5-FU loaded chitosan nanoparticles were found to be low viscosity chitosan 0.5-1 mg/mL, middle viscosity chitosan 0.5-0.8 mg/mL and high viscosity chitosan 0.5-0.75 mg/mL and chitosan/TPP mass ratio of 4 or 6, yielding nanoparticles at the average diameter range of 114-188 nm and encapsulation efficiencies between 42-55%.

Fungus-mediated synthesis of gold nanoparticles: a novel biological approach to nanoparticle synthesis.

The biological effects of nanoparticles and their uses as molecular probes are research areas of growing interest. The present study demonstrates an eco-friendly biosynthesis of gold nanoparticles. The pure colonies of penicillium aurantiogriseum, penicillium citrinum, and penicillium waksmanii were cultured in fluid czapek dox broth. Then, their supernatants were examined for the ability to produce gold nanoparticles. In this step, 1 mM solution of AuCl added to the reaction matrixes separately. The reactions were performed in a dark environment at 28 degrees C. After 24 hours, it was observed that the color of the solutions turned to dark purple from light yellow. Synthesized gold nanoparticles were characterized by using UV-Visible Spectroscopy, Nano Zeta Sizer, Scanning Electron Microscopy and Fourier transformed infrared spectroscopy. The results showed that the gold nanoparticles were formed fairly uniform with spherical shape with the Z-average diameter of 153.3 nm, 172 nm and 160.1 nm for penicillium aurantiogriseum, penicillium citrinum, and penicillium waksmanii, respectively. The Fourier transformed infrared spectra revealed the presence of different functional groups to gold nanoparticles which were present in the fungal extract. The current approach suggests that the rapid synthesis of nanoparticles would be proper for developing a biological process for mass scale production.