Infrared Nanospectroscopy Reveals DNA Structural Modifications upon Immobilization onto Clay Nanotubes.

The growing demand for innovative means in biomedical, therapeutic and diagnostic sciences has led to the development of nanomedicine. In this context, naturally occurring tubular nanostructures composed of rolled sheets of alumino-silicates, known as halloysite nanotubes, have found wide application. Halloysite nanotubes indeed have surface properties that favor the selective loading of biomolecules.

Experimental Evidence of Single-Stranded DNA Adsorption on Multiwalled Carbon Nanotubes.

Noncovalent DNA functionalization is one of the most used routes for the easy dispersion of carbon nanotubes (CNTs) yielding DNA-CNTs complexes with promising applications. Definition of the structure of adsorbed DNA is crucial, but the organization of polymer at the carbon interface is far from being understood. In comparison to single-walled nanotubes, not much effort has been devoted to assessing the structure of the adsorbed DNA on multiwalled carbon nanotubes (MWCNTs), where their metallic nature, large size, and polydispersity represent serious obstacles for both experimental and theoretical studies.

Deoxycholic acid and l-Phenylalanine enrich their hydrogel properties when combined in a zwitterionic derivative.

Hypothesis: Sodium Deoxycholate (NaDC) and Phenylalanine (Phe) are important biological hydrogelators. NaDC hydrogels form by lowering the pH or by increasing the ionic strength. Phe gels form from saturated solution by thermal induction and slow kinetics.

Shear Rheology Control of Wrinkles and Patterns in Graphene Oxide Films.

Drying graphene oxide (GO) films are subject to extensive wrinkling, which largely affects their final properties. Wrinkles were shown to be suitable in biotechnological applications; however, they negatively affect the electronic properties of the films. Here, we report on wrinkle tuning and patterning of GO films under stress-controlled conditions during drying.

Interactions and effects of BSA-functionalized single-walled carbon nanotubes on different cell lines.

Functionalized carbon nanotubes (CNTs) have shown great promise in several biomedical contexts, spanning from drug delivery to tissue regeneration. Thanks to their unique size-related properties, single-walled CNTs (SWCNTs) are particularly interesting in these fields. However, their use in nanomedicine requires a clear demonstration of their safety in terms of tissue damage, toxicity and pro-inflammatory response.

Titration of DNA/Carbon Nanotube Complexes with Double-Chained Oppositely Charged Surfactants.

1/1 dispersions of ss-DNA/CNT complexes in mass ratios were investigated in a mixture with didodecyldimethylammonium bromide, DDAB. Depending on the amounts of the surface-active agent and of the complexes, solutions, precipitates, or re-dissolution occur. DDAB titrates the phosphate groups on the outer surface of the complex and controls the phase sequence in these systems.

Effects of single-walled carbon nanotubes on lysozyme gelation.

The possibility to disperse carbon nanotubes in biocompatible matrices has got substantial interest from the scientific community. Along this research line, the inclusion of single walled carbon nanotubes in lysozyme-based hydrogels was investigated. Experiments were performed at different nanotube/lysozyme weight ratios.

Formation and properties of gels based on lipo-plexes.

Aqueous systems containing sodium taurodeoxycholate and, eventually, soybean lecithin were investigated. Depending on the relative amounts of two such species, molecular, micellar, vesicular, liquid crystalline, and solid phases were formed. In the presence of bovine serum albumin, micellar and vesicular systems form lipo-plexes.

Ion distribution around synthetic vesicles of the cat-anionic type.

Aqueous alkyltrimethylammonium bromides, or dialkyldimethylammonium ones, were mixed with sodium alkyl sulfates and dialkanesulfonates. Depending on the overall surfactant concentration, charge and/or mole ratios, cat-anionic vesicles were formed by mixing nonstoichiometric amounts of oppositely charged species. The resulting vesicles are thermodynamically and kinetically stable.

Delivery of RNA and its intracellular translation into protein mediated by SDS-CTAB vesicles: potential use in nanobiotechnology.

Catanionic vesicles are supramolecular aggregates spontaneously forming in water by electrostatic attraction between two surfactants mixed in nonstoichiometric ratios. The outer surface charges allow adsorption to the biomembrane by electrostatic interactions. The lipoplex thus obtained penetrates the cell by endocytosis or membrane fusion.

Lysozyme binds onto functionalized carbon nanotubes.

Single walled carbon nanotubes have singular physicochemical properties making them attractive in a wide range of applications. Studies on carbon nanotubes and biological macromolecules exist in literature. However, ad hoc investigations are helpful to better understand the interaction mechanisms.

Size and charge modulation of surfactant-based vesicles.

Nonstoichimetric mixtures of two oppositely charged surfactants, such as sodium dodecylsulfate and hexadecyltrimethylammonium bromide or tetradecyltrimethylammonium bromide and tetraethylammonium perfluorooctanesulfonate, a fluorinated species, form vesicles in dilute concentration regimes of the corresponding phase diagrams. Vesicles size and charge density are tuned by changing the mole ratio between oppositely charged species, at fixed overall surfactant content. They are also modulated by adding neutral electrolytes, or raising T.