Monosaccharide-Directed Selective Internalization of Gold and Silver Nanoparticles in Hepatic Cancer Cells

The therapeutic success of nanomedicines requires nanomaterials to either adhere to the surface or internalize within the cytoplasm. The endocytosis phenomenon is controlled by the nanomaterial's shape, size, composition, charge, and capping molecules. The membrane potential-based non-specific internalization of therapeutic nanomedicines offers limited benefits than receptor-based specific delivery. Glut receptor-based internalization of glucose molecules is a well-known process in cancerous cells, which is one of the most exploited strategies to target cancer cells using nanoparticles. However, the internalization process of other structurally similar monosaccharides (D-Galactose, Mannose, and D-Fructose) conjugated nanoparticles remains to be unexplored. Herein, D-Glucose, D-Galactose, Mannose, and D-Fructose-coated AuNPs and AgNPs have been synthesized and studied the role of Glut receptors in their internalization in liver cancer cells, and compared them with non-cancerous cells. Results revealed that almost all monosaccharide-coated NPs exhibited high uptake in liver cancer cells than non-cancerous cells. Glut-1 receptor is observed to play a key role in the uptake and inhibition of Glut-1 receptors by genistein lead to a significant decrease in nanoparticle uptake. In conclusion, monosaccharide-conjugated nanoparticles can be used to direct the selective internalization of AuNPs and AgNPs in hepatic cancer cells to realize therapeutic and imaging applications.     

One-dimensional colloidal gold and silver nanostructures

One-dimensional (1-D) metallic nanoscale materials have long been of interest to many groups of scientists. Within the last 2 decades, great advances in the synthesis of metallic nanorods and nanowires have been made, with a variety of templating methods. More recently, bottom-up chemical syntheses of these materials have become increasingly reported in the literature. This Forum Article describes the synthesis, physical properties, and potential applications of 1-D metals, with an emphasis on silver and gold derived from studies in the authors' laboratories.     

Particle Formation from Single Droplets of Aqueous Solutions of Lead Nitrate

The thermal evolution of droplets of aqueous solution of lead nitrate was studied in a drop-tube furnace, which simulates typical conditions for material synthesis, through spray pyrolysis, and for the thermal destruction of liquid-containing waste. The processes of droplet evaporation, precursor precipitation within the droplet and thermolysis of the precipitated particles were followed by means of the spectral analysis of the ultraviolet light scattered by the aerosol produced during the heating of aqueous droplets (100 μm) of lead nitrate, with different salt concentrations, from ambient temperature up to 1200 K. Dimensions and physico-chemical properties of the droplets/particles were obtained in situ by means of ultraviolet spectra of light scattering (UVSLS) and compared with scanning electron microscopy (SEM) of the sampled material. A plasma generated in the air by an optical breakdown induced by a Nd:YAG laser was employed as the light source in the wavelength range 200–400 nm, thus allowing an exceptionally high photon flux in the ultraviolet region where intense and species-specific interactions with metal species take place. The spray drying process was followed by measuring the light transmitted by the droplets in the backward region. As the drying process progresses, the surface concentration reaches a saturation value and solute is deposited as a solid phase forming a surface crust, which grows steadily. At this point in the process of droplet drying, information was retrieved from the light reflected by the particle interface. Two spectral scattering behaviors were detected at temperatures above the salt precipitation within the droplet. On the basis of Mie calculations and SEM measurements, these behaviors were attributed to lead nitrate particles with typical diameters of the residual droplets (about 50 μm) and to micrometer-sized lead oxide particles. The effect of salt concentration on the drying process and the thermolysis of lead nitrate to oxide was investigated by changing the salt concentration from very dilute conditions up to almost the saturation concentration.     

Controlled dynamics at an avoided crossing interpreted in terms of dynamically fluctuating potential energy curves

The nonadiabatic nuclear wavepacket dynamics on the coupled two lowest (1)Σ(+) states of the LiF molecule under the action of a control pulse is investigated. The control is achieved by a modulation of the characteristics of the potential energy curves using an infrared field with a cycle duration comparable to the time scale of nuclear dynamics. The transition of population between the states is interpreted on the basis of the coupled nuclear wavepacket dynamics on the effective potential curves, which are transformed from the adiabatic potential curves with use of a diabatic representation that diagonalizes the dipole-moment matrix of the relevant electronic states. The basic feature of the transition dynamics is characterized in terms of the notion of the collision between the dynamical crossing point and nuclear wavepackets running on such modulated potential curves, and the transition amplitude is mainly dominated by the off-diagonal matrix element of the time-independent electronic Hamiltonian in the present diabatic representation. The importance of the geometry dependence of the intrinsic dipole moments as well as of the diabatic coupling potential is illustrated both theoretically and numerically.     

Low Temperature Sol-Gel Preparation of Nanocrystalline TiO2 Thin Films

TiO₂ nanocrystalline thin films with varying degree of porosity have been prepared using a low temperature method. TiO₂ films of the anatase form have been obtained by using a polyethylene glycol (PEG) modified sol-gel method. Densification and crystallization of the films was found to result from the thermal treatment of the dip coated films in boiling water. The films have been characterized by Raman, XRD, FTIR, AFM and optical methods. Highly transparent films with transmission in excess of 85% and porosity as high as 58% are formed predominantly of anatase crystallites of dimensions of the order of 5 nm. Initial results on lithium intercalation into these films resulting in an efficient optical modulation in the visible and near infrared regions demonstrate a good potential of these films for electrochromic applications.     

Jaspamides M-P: new tryptophan modified jaspamide derivatives from the sponge Jaspis splendans

Four new jaspamide derivatives with antimicrofilament activity were isolated from the marine sponge Jaspis splendans. Their structures were elucidated by NMR and MS analysis. A structure-activity relationship analysis on all natural jaspamides is also reported here.     

Study of latent fingermarks by matrix‐assisted laser desorption/ionisation mass spectrometry imaging of endogenous lipids

Identification of suspects via fingermark analysis is one of the mainstays of forensic science. The success in matching fingermarks, using conventional fingermark scanning and database searching, strongly relies on the enhancement method adopted for fingermark recovery; this in turn depends on the components present in the fingermarks, which will change over time. This work aims to develop a robust methodology for improved analytical detection of the fingermark components. For the first time, matrix‐assisted laser desorption/ionisation mass spectrometry imaging (MALDI‐MSI) has been used to image endogenous lipids from fresh and aged, groomed and ungroomed fingermarks. The methodology was initially developed using oleic acid which was detected along with its degradation products over a 7‐day period, at three different temperatures in a time‐course experiment. The optimised methodology was then transferred to the imaging analysis of real fingermark samples. Fingermark patterns were reconstructed by retrieving the m/z values of oleic acid and its degradation products. This allowed the three aged fingermarks to be distinguished. In order to prove that MALDI‐MSI can be used in a non‐destructive way, a simple washing protocol was adopted which returned a fingermark that could be further investigated with classical forensic approaches. The work reported here proves the potential and the feasibility of MALDI‐MSI for the forensic analysis of fingermarks, thus making it competitive with other MSI techniques such as desorption electrospray ionisation (DESI)‐MS. The feasibility of using MALDI‐MSI in fingermark ageing studies is also demonstrated along with the potential to be integrated into routine fingermark forensic analysis. Copyright © 2009 John Wiley & Sons, Ltd.     

Poly(dimethylaminoethylmethacrylate) hydrochloride (PDMAEM-HCl) a well behaving polycation for multilayer formation on planar surfaces

The polycation preparation of poly(dimethylaminoethylmethacrylate) hydrochloride and the multilayer formation in combination with poly(sodium 4-styrenesulphonate) as polyanion studies onto different substrates, as followed by streaming potential measurements, in situ surface plasmon resonance spectroscopy, and multi-wavelength ellipsometry, are reported. Furthermore, we studied the resulting multilayer buildup of dry surfaces by UV-Vis spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy measurements. Thereby, the layer built up at the solid/liquid-interface could be followed and quantified at the molecular level.This revised version was published online in April 2005 with corrections to the article category.