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Silver nanoparticles were successfully synthesized from AgNO3through a reliable, eco-friendly and simple green route usingPaederia foetida L.leaf extract as a reducing cum stabilizing agent. UV-Visible Spectroscopy, dynamic light scattering, atomic force microscopy, transmission electron microscopy, and X-ray diffraction analysis were used for characterization of silver nanoparticles. The synthesized silver nanoparticles were spherical in shape with size range of 4–15 nm. The nanoparticles were face-centered cubic crystal structure. The adopted technique for silver nanoparticle synthesis is suitable for large-scale production. The as-prepared silver nanoparticles revealed excellent antibacterial activity against different gram classes of bacteria and would be a promising candidate for various pharmaceutical, biomedical, and environmental applications. [ABSTRACT FROM PUBLISHER]

Spherical, triangular (prismatic) and square plate shaped gold nanoparticles have been synthesised from HAuCl4 · 3H2O solution using the aqueous leaf extract of Cocculus hirsutus. Nanoparticles are characterised using higher resolution transmission electron microscope, X-ray diffraction and UV–Vis absorption spectroscopic study. FT-IR analysis reveals that the gold nanostructures are mostly stabilised by the carbonyl and amide groups present in the active component of C. hirsutus leaf extract. Formation of gold nanostructures of variable morphologies has been explained due to slow reduction of gold ions by the mild reducing ascorbic acid present within the extract and this controlled reduction assists the preferential deposition of Au atom on different lesser-protected faces of initially grown gold nanostructure. [ABSTRACT FROM PUBLISHER]

The poor bioavailability and therapeutic response exhibited by conventional ophthalmic solutions may be overcome by the use of thermo-reversible in situ gel. The purpose of this study was to examine the influence of different salts on the gelation, rheology and drug release of in situ gel based on methylcellulose. The gel temperature of 1% w/v methylcellulose (MC) was 60°°C. It was found that 5--7% w/v sodium chloride (NaCl), 8--9% w/v potassium chloride (KCl), or 5% w/v sodium bicarbonate (NaHCO3) was capable of decreasing the gel temperature below physiological temperature, i.e. 37°°C. Rheological studies indicated a large increase in viscosity at 37°°C with the addition of salts in MC solutions. The duration of drug release from MC solution was 1.5 h. The significant observation was that the duration of drug release increased from 1.5 h to 3--5 h from salted MC solutions depending on the concentration and the type of salt. So, it can be concluded that the salted MC solutions were a better alternative than the MC solution to enhance the ocular bioavailability of the drug. [ABSTRACT FROM AUTHOR]

While the terminally protected tripeptide Boc-Phe-Gly-m-ABA-OMe I (m-ABA, meta-amino benzoic acid) is an excellent gelator of aromatic organic solvents, another similar tripeptide Boc-Leu-Gly-m-ABA-OMe II, where the Phe residue of peptide I is replaced by Leu, cannot form gels with the same solvents. The morphology of the gels of peptide I, characterised by the field-emission scanning electron microscopy and high-resolution transmission electron microscopy, reveals the formation of nanofibrous networks which are known to encapsulate solvent molecules to form gels. The wide-angle X-ray scattering studies of the gels suggest the β-sheet-mediated self-assembly of peptide I in the formation of a nanofibrous network, where π-stacking interactions of Phe play an important role in the self-assembly and gel formation. The dried gel of peptide I observed between crossed polarisers after binding with a physiological dye, Congo red, shows a bluish-green birefringence, a characteristic of amyloid fibrils. [ABSTRACT FROM AUTHOR]