pH-dependent disintegration of insulin amyloid fibrils monitored with atomic force microscopy and surface-enhanced Raman spectroscopy.

Aggregation of insulin into amyloid fibrils is characterized by the conversion of the native secondary structure of the peptide into an enriched ß-sheet conformation. In vitro, the growth or disintegration of amyloid fibrils can be influenced by various external factors such as pH, temperature etc. While current studies mainly focus on the influence of environmental conditions on the growth process of insulin fibrils, the present study investigates the effect of pH changes on the morphology and secondary structure of mature fibrils.

Uptake of fatty acids by a single endothelial cell investigated by Raman spectroscopy supported by AFM.

In this work, confocal Raman imaging was used to study the formation of lipid droplets (LDs) in vitro in a single endothelial cell upon incubation with polyunsaturated fatty acids (10 or 25 μM) including arachidonic acid (AA) and its deuterated analog (AA-d), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Based on the Raman spectra obtained from a single endothelial cell, it was possible to investigate biochemical changes induced by addition of polyunsaturated fatty acids. In particular, the content of lipids in the formed LDs and the unsaturation degree were identified by Raman spectroscopy by marker bands at 1660 cm due to the C[double bond, length as m-dash]C stretching and at ∼3015 cm due to the stretching mode of [double bond, length as m-dash]C-H associated with C[double bond, length as m-dash]C double bonds (except for a deuterated form where these bands are shifted respectively).

On the Control of Chromophore Orientation, Supramolecular Structure, and Thermodynamic Stability of an Amphiphilic Pyridyl-Thiazol upon Lateral Compression and Spacer Length Variation.

The supramolecular structure essentially determines the properties of organic thin films. Therefore, it is of utmost importance to understand the influence of molecular structure modifications on supramolecular structure formation. In this article, we demonstrate how to tune molecular orientations of amphiphilic 4-hydroxy thiazole derivatives by means of the Langmuir-Blodgett (LB) technique and how this depends on the length of an alkylic spacer between the thiazole chromophore and the polar anchor group.