Three dimensional cellular microarray platform for human neural stem cell differentiation and toxicology.

We developed a three-dimensional (3D) cellular microarray platform for the high-throughput (HT) analysis of human neural stem cell (hNSC) growth and differentiation. The growth of an immortalized hNSC line, ReNcell VM, was evaluated on a miniaturized cell culture chip consisting of 60nl spots of cells encapsulated in alginate, and compared to standard 2D well plate culture conditions. Using a live/dead cell viability assay, we demonstrated that the hNSCs are able to expand on-chip, albeit with lower proliferation rates and viabilities than in conventional 2D culture platforms.

FGF-FGFR signaling mediated through glycosaminoglycans in microtiter plate and cell-based microarray platforms.

Fibroblast growth factor (FGF) signals cell growth through its interaction with a fibroblast growth factor receptor (FGFR) and a glycosaminoglycn (GAG) coreceptor. Here, we examine the signaling of five different FGFs (1, 2, 6, 8, and 8b) through FGFR3c. A small library of GAG and GAG-derivative coreceptors are screened to understand better the structure-activity relationship of these coreceptors on signaling.

Microarray platform affords improved product analysis in mammalian cell growth studies.

High throughput (HT) platforms serve as a cost-efficient and rapid screening method for evaluating the effect of cell-culture conditions and screening of chemicals. We report the development of a HT cell-based microarray platform to assess the effect of culture conditions on Chinese hamster ovary (CHO) cells. Specifically, growth, transgene expression and metabolism of a GS/methionine sulphoximine (MSX) CHO cell line, which produces a therapeutic monoclonal antibody, was examined using a microarray system in conjunction with a conventional shake flask platform in a non-proprietary medium.

Influence of a three-dimensional, microarray environment on human cell culture in drug screening systems.

We have used a modified 3D cellular microarray platform for the high-throughput analysis of growth, cytotoxicity, and protein expression profile of a human hepatocellular carcinoma cell line, HepG2, in alginate. The results obtained were compared to analogous studies in 2D and 3D environments at the microtiter scale. The antiproliferative effects of four drugs, tamoxifen, 5-fluorouracil, doxorubicin, and amitriptyline, were studied as a function of seeding density in the three different culture platforms.

Room temperature ionic liquids as emerging solvents for the pretreatment of lignocellulosic biomass.

Room temperature ionic liquids (RTILs) are emerging as attractive and green solvents for lignocellulosic biomass pretreatment. The unique solvating properties of RTILs foster the disruption of the 3D network structure of lignin, cellulose, and hemicellulose, which allows high yields of fermentable sugars to be produced in subsequent enzymatic hydrolysis. In the current review, we summarize the physicochemical properties of RTILs that make them effective solvents for lignocellulose pretreatment including mechanisms of interaction between lignocellulosic biomass subcomponents and RTILs.

Aggregation and coarsening of ligand-stabilized gold nanoparticles in poly(methyl methacrylate) thin films.

Dodecanethiol-stabilized gold nanoparticles (5 nm diameter) are shown to self-organize to form a two-dimensional hexagonal structure in poly(methyl methacrylate) films upon spin-casting from solution onto a substrate, using high-angle annular dark-field scanning transmission electron microscopy. Through use of the distribution functions describing particle distributions, we show that the particle coarsening dynamics is self-similar, characterized by two distinct growth stages. During the initial stage, coarsening occurs via simultaneous Ostwald ripening and coalescence mechanisms, whereas during the second stage, the dominant coarsening mechanism is coalescence.

Glass transition of polymer-nanocrystal thin film mixtures: role of entropically directed forces on nanocrystal distribution.

The connection between the average properties of a polymer/nanocrystal hybrid material and the nanocrystal spatial distribution is shown. Specifically, a property such as the glass transition temperature, Tg, is shown to vary by as much as 65 degrees C through only changes in the spatial distribution of the nanocrystals. Considerable control can be exercised over the nanoparticle spatial distribution.

Polystyrene thin films in CO(2).

In air, or vacuum environments, liquid polystyrene (PS) thin films (thickness, h<100 nm ) supported by SiOx /Si substrates are structurally metastable or unstable, depending on film thickness. They rupture and eventually form droplets on the SiOx /Si substrates (dewet) due to the influence of destabilizing long-ranged van der Waals dispersion forces. We used scanning force microscopy to examine the structural stability of liquid PS films in the thickness range 5 nm View Article and Find Full Text PDF