Langmuir–Blodgett Films of Diketopyrrolopyrroles with Tunable Amphiphilicity

Maximilian L. Hupfer, Beata Koszarna, Soumik Ghosh, Daniel T. Gryko, and Martin Presselt

Langmuir 2021

In this work, we present the formation of H- and J-aggregates of amphiphilic centrosymmetric diketopyrrolopyrroles containing aliphatic or aromatic amino groups. The inherent amphiphilicity of these dyes predestines their assembly at interfaces to form ordered supramolecular structures. We employed the Langmuir–Blodgett (LB) technique to generate, manipulate, and deposit such supramolecular structures. The aforementioned amines provide an additional means to control the formation of the supramolecular assemblies. In the resulting LB films, both H- and J-aggregates of the dyes can be realized, leading to very broad absorption spectra. In contrast to many reports on H- and J-aggregates, the interactions between the symmetric diketopyrrolopyrroles are controlled via interface assembly and π-stacking and not by dipolar interactions.

Toward Raman Subcellular Imaging of Endothelial Dysfunction

Adriana Adamczyk, Ewelina Matuszyk, Basseem Radwan, Stefano Rocchetti, Stefan Chlopicki, and Malgorzata Baranska

Journal of Medicinal Chemistry 2021

Multiple diseases are at some point associated with altered endothelial function, and endothelial dysfunction (ED) contributes to their pathophysiology. Biochemical changes of the dysfunctional endothelium are linked to various cellular organelles, including the mitochondria, endoplasmic reticulum, and nucleus, so organelle-specific insight is needed for better understanding of endothelial pathobiology. Raman imaging, which combines chemical specificity with microscopic resolution, has proved to be useful in detecting biochemical changes in ED at the cellular level. However, the detection of spectroscopic markers associated with specific cell organelles, while desirable, cannot easily be achieved by Raman imaging without labeling. This critical review summarizes the current advances in Raman-based analysis of ED, with a focus on a new approach involving molecular Raman reporters that could facilitate the study of biochemical changes in cellular organelles. Finally, imaging techniques based on both conventional spontaneous Raman scattering and the emerging technique of stimulated Raman scattering are discussed.

Multiplex Raman imaging of organelles in endothelial cells

Ewelina Matuszy, Adriana Adamczyk, Basseem Radwan, Anna Pieczara, Piotr Szcześniak, Jacek Mlynarski, Katarzyna Kamińska, Malgorzata Baranska 

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2021

The aim of this work is to visualize the main cell organelles in endothelial cells (HMEC-1) using established reporters (EdU and MitoBADY), but also to test a new Raman reporter, namely falcarinol, which exhibits lipophilic properties. Moreover, we tested the possibility to use Raman reporters as a probe to detect changes in distribution of certain organelles after induced endothelial dysfunction (ED) in in vitro models. In both cases, induced ED is characterized by the formation of lipid droplets in the cells, which is why a good tool for the detection of lipid-rich organelles is so important in these studies.

Astaxanthin as a new Raman probe for biosensing of specific subcellular lipidic structures: can we detect lipids in cells under resonance conditions?

Krzysztof Czamara, Adriana Adamczyk, Marta Stojak, Basseem Radwan, Malgorzata Baranska 

Cellular and Molecular Life Sciences 2020

Here we report a new Raman probe for cellular studies on lipids detection and distribution. It is (3S, 3’S)-astaxanthin (AXT), a natural xanthophyll of hydrophobic properties and high solubility in lipids. We showed that AXT accumulates in lipidic structures of endothelial cells in time-dependent manner that provides possibility to visualize e.g. endoplasmic reticulum, as well as nuclear envelope. As a non-toxic reporter, it has a potential in the future studies on e.g. nucleus membranes damage in live cells in a very short measuring time.

Labeled vs. Label-Free Raman Imaging of Lipids in Endothelial Cells of Various Origins

Basseem Radwan, Adriana Adamczyk, Szymon Tott, Krzysztof Czamara, Katarzyna Kaminska, Ewelina Matuszyk, Malgorzata Baranska

Molecules 2020

Endothelial dysfunction has been recognized as a primary or secondary cause of many diseases and it manifests itself, among others, by increased lipid content or a change in the lipid composition in the EC. Therefore, the analysis of cellular lipids is crucial to understand the mechanisms of disease development. Tumor necrosis factor alpha (TNF-α)-induced inflammation of EC alters the lipid content of cells, which can be detected by Raman spectroscopy. We consider (3S,3′S)-astaxanthin (AXT), a natural dye with a characteristic resonance spectrum, as a new Raman probe for the detection of lipids in the EC of various vascular beds, i.e., the aorta, brain and heart. AXT colocalizes with lipids in cells, enabling imaging of lipid-rich cellular components in a time-dependent manner using laser power 10 times lower than that commonly used to measure biological samples.

Interaction of Miltefosine with Microcavity Supported Lipid Membrane: Biophysical Insights from Electrochemical Impedance Spectroscopy

Nirod Kumar Sarangi, Amrutha Prabhakaran, Tia E. Keyes

Electroanalysis 2020

Miltefosine an alkylphosphocholine analogue, is the only drug taken orally for the treatment of leishmaniasis‐a parasitic disease caused by sandflies. Although it is believed that Miltefosine exerts its activity by acting at the lipid membrane, detailed understanding of the interaction of this drug with eukaryotic membranes is still lacking. Herein, we exploit microcavity pore suspended lipid bilayers (MSLBs) as a biomimetic platform in combination with a highly sensitive label‐free electrochemical impedance spectroscopy (EIS) technique to gain biophysical insight into the interaction of Miltefosine with host cell membrane as a function of lipid membranes composition.