Diamine Functionalized Cubic Mesoporous Silica for Ibuprofen Controlled Delivery.

A diamine functionalized cubic mesostructured KIT-6 (N-KIT-6) has been prepared by post-synthetic method using calcined mesoporous KIT-6 with a diamine source, i.e., N-'[3-(tri methoxysilyl)- propyl]'ethylenediamine. The KIT-6 mesoporous silica used for N-KIT-6 was synthesized under weak acidic hydrothermal method using bitemplates, viz., Pluronic P123 and 1-butanol. The synthesized mesoporous materials, KIT-6 and N-KIT-6, have been characterized by the relevant instrumental techniques such as SAXS, N2 sorption isotherm, FT-IR, SEM, TEM and TGA to prove the standard mesoporous materials with the identification of diamine groups. The characterized mesoporous materials, KIT-6 and N-KIT-6, have been extensively used in the potential application of controlled drug delivery, where ibuprofen (IBU) employed as a model drug. The rate of IBU adsorption and release was monitored by UV vis-spectrometer. On the basis of the experimental results of controlled drug delivery system, the results of IBU adsorption and releasing rate in N-KIT-6 are higher than those of KIT-6 because of the higher hydrophobic nature as well as rich basic sites on the surface of inner pore wall silica.

Development of inorganic and organic hybrid nanocoating based on carbon nanotubes for corrosion resistance.

In this study, we report the synthesis and characterization of novel hybrid nanocoating based on carbon nanotubes (CNTs) on anodized aluminum surfaces (AAO). The hybrid nanocoating was deposited by number of methods which include spray coating, spin coating and dip coating. The bonding of nanocoating with metal surface is an important parameter for successful modification of the metal surfaces. The improved adhesion of nanocoating on metal surfaces could be attributed to chemical bonding of sol-gel nanocoating with anodized surfaces. The nanocoated anodized aluminum surfaces showed superior adhesion and excellent anticorrosive properties. The nanocoated panels showed enhanced galvanic protection comparable to 80% of titanium metal as determined by galvanic corrosion measurements. It also showed higher thermal conductivities than stainless steel and bare anodized surfaces.

Ataxia-telangiectasia: identification and detection of founder-effect mutations in the ATM gene in ethnic populations.

To facilitate the evaluation of ATM heterozygotes for susceptibility to other diseases, such as breast cancer, we have attempted to define the most common mutations and their frequencies in ataxia-telangiectasia (A-T) homozygotes from 10 ethnic populations. Both genomic mutations and their effects on cDNA were characterized. Protein-truncation testing of the entire ATM cDNA detected 92 (66%) truncating mutations in 140 mutant alleles screened. The haplotyping of patients with identical mutations indicates that almost all of these represent common ancestry and that very few spontaneously recurring ATM mutations exist. Assays requiring minimal amounts of genomic DNA were designed to allow rapid screening for common ethnic mutations. These rapid assays detected mutations in 76% of Costa Rican patients (3), 50% of Norwegian patients (1), 25% of Polish patients (4), and 14% of Italian patients (1), as well as in patients of Amish/Mennonite and Irish English backgrounds. Additional mutations were observed in Japanese, Utah Mormon, and African American patients. These assays should facilitate screening for A-T heterozygotes in the populations studied.

Rapid identification of lectin receptors and their possible function in sea urchin cell systems.

An assay using lectin derivatized agarose beads to rapidly and inexpensively identify cell surface lectin receptors was recently described by Latham et al. (1995). In this earlier study, the assay was tested on large, early stage sea urchin embryo cells. In this study this assay was used to examine lectin receptors on small, later stage sea urchin embryo cells that are more typical of cells that most investigators deal with, to ascertain if cell size is a determining factor in the assay's validity. The results indicated that the assay is a valid method to identify lectin receptors on small as well as large cells. Twenty-three hour Strongylocentrotus purpuratus embryo cells strongly bound Triticum vulgaris, concanavalin A, Artocarpus integrifolia and Vicia villosa using both the agarose bead and fluorescence assays, while three other lectins, Ulex europaeus I, Lotus tetragonolobus and Lens culinaris did not strongly bind to the cells using these two assays. As in earlier studies agglutinability results did not correlate well with results using the two other assays. In all cases where lectin bead binding, fluorescent lectin binding or lectin-mediated agglutination occurred, specific sugars reduced the observed binding. The second part of this study examined the putative role of concanavilin A receptors in a specific cellular interaction: sperm-egg binding. Concanavalin A inhibited fertilization of dejellied sea urchin eggs when their vitelline layers were intact and to a lesser extent when their vitelline layers were removed. This effect was counteracted by alpha methyl glucose. The major differences between these studies and previous work is that here concanavalin A was washed out after incubation with eggs, making it more likely that results reflect binding to cell surface lectin receptors rather than toxicity. In addition, performing the experiments on eggs with or without vitelline layers provided information on the location of concanavalin A receptors that may function in sperm-egg interaction.

A rapid lectin receptor binding assay: comparative evaluation of sea urchin embryo cell surface lectin receptors.

Lectin receptor binding assays, such as those that utilize fluorescence, radioactivity or electron microscopy are not designed for rapidly screening hundreds of cell types for the presence or absence of specific lectin receptors. An assay is described here that is designated for this purpose. It utilizes lectins derivatized to agarose beads and can be used to screen many cell types in min. This assay was used to examine lectin receptors on the surfaces of 1-8 cell stage Strongylocentrotus purpuratus sea urchin embryos. The same cells were also assayed using standard fluorescence and agglutinability procedures to ascertain the type of information obtained by the new assay and how it correlates with results from the standard methods. The bead results correlated well with results using fluorescent lectin. Only wheat germ agglutinin bound very strongly in both bead and fluorescence assays, while concanavalin A, Dolichos biflorus, Lens culinaris and Tetragonolobus purpureas did not bind or bound weakly using both methods. Results using a third method, lectin mediated cell agglutination, did not correlate with the bead or fluorescence assays. Lectin receptors were also examined on embryos prepared by two different methods of preventing formation of fertilization membranes, so that coat-free cell surfaces could be studied, the standard dithiothreitol method and a new method using alpha-amylase. Lectin receptors on the cell surfaces of embryos prepared by both methods were nearly identical. The possible functions of WGA receptors, the most prevalent lectin receptors of those studied, that were uniformly present throughout early development of this sea urchin species, are considered.(ABSTRACT TRUNCATED AT 250 WORDS)