Antibodies under pressure: A Small-Angle X-ray Scattering study of Immunoglobulin G under high hydrostatic pressure.

In the present work two subclasses of the human antibody Immunoglobulin G (IgG) have been investigated by Small-Angle X-ray Scattering under high hydrostatic pressures up to 5kbar. It is shown that IgG adopts a symmetric T-shape in solution which differs significantly from available crystal structures. Moreover, high-pressure experiments verify the high stability of the IgG molecule.

Interaction of differently functionalized fluorescent silica nanoparticles with neural stem- and tissue-type cells.

Engineered amorphous silica nanoparticles (SiO2 NPs), due to simple and low cost production, are increasingly used in commercial products and produced on an industrial scale. Despite the potential benefits, there is a concern that exposure to certain types of SiO2 NPs may lead to adverse health effects. As some NPs can cross the blood--brain barrier and may, in addition, reach the central nervous system through the nasal epithelium, this study addresses the responses of different neural tissue-type cells including neural stem cells, neurons, astrocytes and microglia cells to increasing doses of 50 nm fluorescent core/shell SiO2 NPs with different [-NH2, -SH and polyvinylpyrrolidone (PVP)] surface chemistry.

Altered characteristics of silica nanoparticles in bovine and human serum: the importance of nanomaterial characterization prior to its toxicological evaluation.

Background: Many toxicological studies on silica nanoparticles (NPs) have been reported, however, the literature often shows various conclusions concerning the same material. This is mainly due to a lack of sufficient NPs characterization as synthesized as well as in operando. Many characteristics of NPs may be affected by the chemistry of their surroundings and the presence of inorganic and biological moieties.

Toward advancing nano-object count metrology: a best practice framework.

Background: A movement among international agencies and policy makers to classify industrial materials by their number content of sub-100-nm particles could have broad implications for the development of sustainable nanotechnologies.

Objectives: Here we highlight current particle size metrology challenges faced by the chemical industry due to these emerging number percent content thresholds, provide a suggested best-practice framework for nano-object identification, and identify research needs as a path forward.

Discussion: Harmonized methods for identifying nanomaterials by size and count for many real-world samples do not currently exist.

Cytotoxicity screening of 23 engineered nanomaterials using a test matrix of ten cell lines and three different assays.

Background: Engineered nanomaterials display unique properties that may have impact on human health, and thus require a reliable evaluation of their potential toxicity. Here, we performed a standardized in vitro screening of 23 engineered nanomaterials. We thoroughly characterized the physicochemical properties of the nanomaterials and adapted three classical in vitro toxicity assays to eliminate nanomaterial interference.

A reversibly switching block copolymer surface.

We present linear (AB)(n)() multiblock copolymers that exhibit a thermally induced reversible alteration of the surface composition at a sharply defined transition temperature T(s) of 120-170 degrees C depending on the polymer structure. At temperatures below T(s) the surface consists of block A, a 4,4'-methylenediphenyl diisocyanate (4,4'-MDI) type polyurea, whereas above T(s) the hydrophobic block B, a poly(ricinoleic acid hexanediol ester) dominates the surface composition. The ratio of surface concentrations c(A)/c(B) changes by a factor of at least 1000 within an analyzed depth of approximately 10 A.