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A nanoformulation composed of a ribosome inactivating protein-curcin and a hybrid solid lipid nanovector has been devised against glioblastoma. The structurally distinct nanoparticles were highly compatible to human endothelial and neuronal cells. A sturdy drug release from the particles, recorded upto 72 h, was reflected in the time-dependent toxicity. Folate-targeted nanoparticles were specifically internalized by glioma, imparting superior toxicity and curbed an aggressively proliferating in vitro 3D cancer mass in addition to suppressing the anti-apoptotic survivin and cell matrix protein vinculin. Combined with the imaging potential of the encapsulated dye, the nanovector emanates as a multifunctional anti-cancer system.

Extremophiles are the group of organisms that are far overlooked for exploring novel biomaterials in the field of material science and bionanotechnology. Extremophilic bacterial-sulfated exopolysaccharide, mauran (MR), is employed for the bioreduction and passivation of gold nanoparticles (AuNps) to enhance the biocompatibility of AuNps and used for photothermal ablation of cancer cells. Here, various concentrations of MR solution are tested for the reduction of HAuCl4 solution in the presence as well as in the absence of an external reducing agent, to produce mauran-gold nanoparticles (MRAu Nps). These biocompatible nanocomposites are treated with cancer cell lines under in vitro conditions and NIR irradiated for complete ablation. MRAu Nps-treated cancer cells on immediate exposure to infrared radiation from a femtosecond pulse laser of operating wavelength 800 nm are subjected to hyperthermia causing cell death. Biocompatible MR stabilization could fairly reduce the cytotoxicity caused by bare AuNps during biomedical applications. Application of a biocompatible polysaccharide from extremophilic bacterial origin for reduction and passivation of AuNps and used for a biomedical purpose is known to be first of its kind in bionanofusion studies.

Highly conductive biocompatible graphene is synthesized using ecofriendly reduction of graphene oxide (GO). Two strains of non-pathogenic extremophilic bacteria are used for reducing GO under both aerobic and anaerobic conditions. Degree of reduction and quality of bacterially reduced graphene oxide (BRGO) are monitored using UV–vis spectroscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. Structural morphology and variation in thickness are characterized using electron microscopy and atomic force microscopy, respectively. Electrical measurements by three-probe method reveal that the conductivity has increased by 104–105 fold from GO to BRGO. Biocompatibility assay using mouse fibroblast cell line shows that BRGO is non-cytotoxic and has a tendency to support as well as enhance the cell growth under laboratory conditions. Hereby, a cost effective, non-toxic bulk reduction of GO to biocompatible graphene for green electronics and bioscience application is achieved using halophilic extremophiles for the first time.

Liposomes and polymers are widely used drug carriers for controlled release since they offer many advantages like increased treatment effectiveness, reduced toxicity and are of biodegradable nature. In this work, anticancer drug-loaded PLGA-lecithin-PEG nanoparticles (NPs) were synthesized and were functionalized with AS1411 anti-nucleolin aptamers for site-specific targeting against tumor cells which over expresses nucleolin receptors. The particles were characterized by transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The drug-loading efficiency, encapsulation efficiency and in vitro drug release studies were conducted using UV spectroscopy. Cytotoxicity studies were carried out in two different cancer cell lines, MCF-7 and GI-1 cells and two different normal cells, L929 cells and HMEC cells. Confocal microscopy and flowcytometry confirmed the cellular uptake of particles and targeted drug delivery. The morphology analysis of the NPs proved that the particles were smooth and spherical in shape with a size ranging from 60 to 110 nm. Drug-loading studies indicated that under the same drug loading, the aptamer-targeted NPs show enhanced cancer killing effect compared to the corresponding non-targeted NPs. In addition, the PLGA-lecithin-PEG NPs exhibited high encapsulation efficiency and superior sustained drug release than the drug loaded in plain PLGA NPs. The results confirmed that AS1411 aptamer-PLGA-lecithin-PEG NPs are potential carrier candidates for differential targeted drug delivery. Biotechnol. Bioeng. 2012; 109: 2920–2931. © 2012 Wiley Periodicals, Inc.

In situ atom transfer radical polymerization techniques have been used to produce polymer-grafted carbon spheres (CSs). The surfaces of as-prepared CSs were functionalized in the presence of CS-supported macroinitiators. The resulting materials were characterized by FTIR and NMR spectroscopy, TGA, SEM, TEM, and HRTEM. The amount of polymer grafted onto the surfaces of the spheres can be controlled by varying the monomer/initiator feed ratio. The wetting ability and dispersibility of the polymer-grafted CSs were improved significantly, compared with crude CSs, enabling stable dispersions in organic solvents to be produced. SEM and TEM studies indicate that a uniform distribution of the carbon spheres in the continuous polymer phase can be produced.

An anti-ulcer drug, geranylgeranylacetone (GGA), stimulates hexosamine production in a rat gastric mucosal cell line (RGM-1). The aim of this study was to elucidate the mechanism of this action. The role of protein kinase A, inositol phospholipid turnover and tyrosine kinase in the stimulatory action of GGA on hexosamine production in RGM-1 was determined by observing cAMP production, [3H]-inositol phosphate turnover and western blotting of tyrosine phosphorylation, respectively. Any trophic effect of GGA on RGM-1 was also checked by [3H]-thymidine incorporation. Our experiments showed that GGA has no effect on cAMP production, inositol phospholipid turnover, tyrosine phosphorylation or DNA synthesis in RGM-1. Finally, a [14C]-GGA competitive receptor binding assay was performed on RGM-1 and we found that [14C]-GGA specifically bound to RGM-1 cytosolic protein. Although retinoic acid (RA), another polyisoprenoid compound significantly stimulated hexosamine production in RGM-1, we confirmed that the [14C]-GGA binding site in RGM-1 is different from the RA binding site. In summary, GGA stimulates hexosamine production in RGM-1 and this action is probably mediated through its binding to a specific cytosolic protein in RGM-1.

Precise control of the placement and patterning of graphene on various substrates has tremendous impact in many fields, such as nanoscale electronics, multifunctional optoelectronic devices, and molecular sensing. A one-step facile technique involving N2-plasma promotes surface modification and enhances the surface wettability of the substrate. The technique is employed to create partially hydrophilic surfaces on SiO2/Si substrate with the aid of various templates, enabling the selective deposition, alignment, and formation of patterns comprising monolayer graphene oxide (GO) sheets; it successfully uses the Langmuir–Blodgett (LB) deposition technique over a large area without the need of any sophisticated equipment. Various characterization techniques are carried out in order to understand the possible mechanism behind the pinning of the GO on the partially treated areas. It is a relatively easy and swift process that can reliably accomplish specific surface modification with high bonding strength between GO and the substrate. This technique allows the creation of patterns with controllable dimensions. For example, the thickness of the GO sheets can be controlled; this is particularly important in creating arrays and devices at wafer-scale. Being simple yet effective and inexpensive, this technique holds tremendous potential that can be exploited for numerous applications in the field of bio-nanoelectronics.