DOX-DNA interactions on the nanoscale : in situ studies using tip-enhanced Raman scattering

Chemotherapeutic anthracyclines, like doxorubicin (DOX), are drugs endowed with cytostatic activity and are widely used in antitumor therapy. Their molecular mechanism of action involves the formation of a stable anthracycline-DNA complex, which prevents cell division and results in cell death. It is known that elevated DOX concentrations induce DNA chain loops and overlaps. Here, for the first time, tip-enhanced Raman scattering was used to identify and localize intercalated DOX in isolated double-stranded calf thymus DNA, and the correlated near-field spectroscopic and morphologic experiments locate the DOX molecules in the DNA and provide further information regarding specific DOX-nucleobase interactions. Thus, the study provides a tool specifically for identifying intercalation markers and generally analyzing drug–DNA interactions. The structure of such complexes down to the molecular level provides mechanistic information about cytotoxicity and the development of potential anticancer drugs

Different route of hydroxide incorporation and thermal stability of new type of water clathrate : X-ray single crystal and Raman investigation

Chlormayenite Ca12Al14O32[♦4Cl2] (♦-vacancy) is partially hydrated micro porouss mineral with hydroxide groups situated at various crystallographic sites. There are few mechanisms describing its hydration. The first one assumes Cl- substitution by OH- at the center of the structural cages (W-site). The second one determines the converting a T1O4 tetrahedron to a T1O3(OH)3 octahedron due to the replacement of oxygen at the O2 site by three OH-groups according to the scheme: (O2O2- + W Cl-) → 3 × O2aOH. The third mechanism, not considered so far in the case of zeolite-like minerals, includes the hydroxide incorporation in form of hydrogarnet defect due to the arrangement of tetrahedral (OH)4 in vacant cages. This yields a strong hydrated phase containing even up to 35% of water more than in any currently known mineral applicable to Portland cement. Moreover, water molecules present in different structural cages are stable up to 355 K while dehydroxylation linked to the gradual loss of only 8% of OH- groups according to 3 O2aOH- → O2O2- + W OH- + gH2O occurs at temperature range from 355 K to 598 K

Application of infrared absorption microspectroscopy and linear regression model to ex vivo analysis of secondary structures of proteins in animal tissues

FT-IR microspectroscopy in combination with chemometrisc is one of the most important modern analytical techniques used in studying biological materials, such as tissues or cells. It allows for identification and studying the spatial distribution of biochemical components in the sample while providing a high level of selectivity and resolution. Chemometrics, which is based on computational, statistical and mathematical methods to analyze chemical data, is a powerful tool in the study of animal tissues and observing the lesions. This paper presents an application of a linear regression model and infrared absorption spectroscopy (FT-IR) to analyze of changes in the biochemical profile of tissue caused by diabetic disease.Mikrospektroskopia FT-IR w połączeniu z chemometrią jest jedną z najważniejszych współczesnych technik analitycznych wykorzystywanych w badaniach materiałów biologicznych, takich jak tkanki czy komórki. Pozwala ona na identyfikację oraz badanie przestrzennej dystrybucji składników biochemicznych w badanym materiale, zapewniając jednocześnie wysoki poziom selektywności i rozdzielczości. Chemometria, wykorzystująca metody komputerowe, statystyczne oraz matematyczne w analizowaniu danych chemicznych, stanowi potężne narzędzie w badaniu tkanek zwierzęcych w celu obserwowania zmian chorobowych. W niniejszej pracy przedstawiono zastosowanie modelu regresji liniowej oraz spektroskopii absorpcyjnej w podczerwieni (FT-IR) do analizy zmian w profilu biochemicznym tkanki wywołanych przez chorobę cukrzycową.

Zastosowanie mikrospektroskopii absorpcyjnej w podczerwieni oraz modelu regresji liniowej do analizy ex vivo struktur drugorzędowych białek w tkankach zwierzęcych

Abstarct: FT-IR microspectroscopy in combination with chemometrisc is one of the most important modern analytical techniques used in studying biological materials, such as tissues or cells. It allows for identification and studying the spatial distribution of biochemical components in the sample while providing a high level of selectivity and resolution. Chemometrics, which is based on computational, statistical and mathematical methods to analyze chemical data, is a powerful tool in the study of animal tissues and observing the lesions. This paper presents an application of a linear regression model and infrared absorption spectroscopy (FT-IR) to analyze ofchanges in the biochemical profile of tissue caused by diabetic disease.Mikrospektroskopia FT-IR w połączeniu z chemometrią jest jedną z najważniejszych współczesnych technik analitycznych wykorzystywanych w badaniach materiałów biologicznych, takich jak tkanki czy komórki. Pozwala ona na identyfikację oraz badanie przestrzennej dystrybucji składników biochemicznych w badanym materiale, zapewniając jednocześnie wysoki poziom selektywności irozdzielczości. Chemometria, wykorzystująca metody komputerowe, statystyczne oraz matematyczne w analizowaniu danych chemicznych, stanowi potężne narzędzie w badaniu tkanek zwierzęcych w celu obserwowania zmian chorobowych. W niniejszej pracy przedstawiono zastosowanie modelu regresji liniowej oraz spektroskopii absorpcyjnej w podczerwieni (FT-IR) do analizy zmian w profilu biochemicznym tkanki wywołanych przez chorobę cukrzycową.

Chloroquine-Induced Accumulation of Autophagosomes and Lipids in the Endothelium

Chloroquine (CQ) is an antimalarial drug known to inhibit autophagy flux by impairing autophagosome–lysosome fusion. We hypothesized that autophagy flux altered by CQ has a considerable influence on the lipid composition of endothelial cells. Thus, we investigated endothelial responses induced by CQ on human microvascular endothelial cells (HMEC-1). HMEC-1 cells after CQ exposure were measured using a combined methodology based on label-free Raman and fluorescence imaging. Raman spectroscopy was applied to characterize subtle chemical changes in lipid contents and their distribution in the cells, while the fluorescence staining (LipidTox, LysoTracker and LC3) was used as a reference method. The results showed that CQ was not toxic to endothelial cells and did not result in the endothelial inflammation at concentrations of 1–30 µM. Notwithstanding, it yielded an increased intensity of LipidTox, LysoTracker, and LC3 staining, suggesting changes in the content of neutral lipids, lysosomotropism, and autophagy inhibition, respectively. The CQ-induced endothelial response was associated with lipid accumulation and was characterized by Raman spectroscopy. CQ-induced autophagosome accumulation in the endothelium is featured by a pronounced alteration in the lipid profile, but not in the endothelial inflammation. Raman-based assessment of CQ-induced biochemical changes offers a better understanding of the autophagy mechanism in the endothelial cells

Unsaturated lipid bodies as a hallmark of inflammation studied by Raman 2D and 3D microscopy

Endothelial HMEC-1 cells incubated with pro-inflammatory cytokine TNF-α for 6 and 24 hours were studied as a model of inflammation using Raman imaging. Striking changes in distribution, composition and concentration of cellular lipids were observed after exposure to TNF-α compared to the control. In particular, 3D Raman imaging revealed a significant increase in the amount of lipid entities formed under inflammation. Lipid bodies were randomly distributed in the cytoplasm and two types of droplets were assembled: more saturated one, in spectral characteristics resembling phosphatidylcholine and saturated cholesteryl esters, observed also in the control, and highly unsaturated one, containing also cholesterols, being a hallmark of inflamed cells. The statistical analysis showed that the number of lipid bodies was significantly dependent on the exposure time to TNF-α. Overall, observed formation of unsaturated lipid droplets can be directly correlated with the increase in production of prostacyclins - endogenous inflammation mediators

Apatite from NWA 10153 and NWA 10645 : the key to deciphering magmatic and fluid evolution history in Nakhlites

Apatites from Martian nakhlites NWA 10153 and NWA 10645 were used to obtain insight into their crystallization environment and the subsequent postcrystallization evolution path. The research results acquired using multi-tool analyses show distinctive transformation processes that were not fully completed. The crystallization history of three apatite generations (OH-bearing, Cl-rich fluorapatite as well as OH-poor, F-rich chlorapatite and fluorapatite) were reconstructed using transmission electron microscopy and geochemical analyses. Magmatic OH-bearing, Cl-rich fluorapatite changed its primary composition and evolved toward OH-poor, F-rich chlorapatite because of its interaction with fluids. Degassing of restitic magma causes fluorapatite crystallization, which shows a strong structural affinity for the last episode of system evolution. In addition to the three apatite generations, a fourth amorphous phase of calcium phosphate has been identified with Raman spectroscopy. This amorphous phase may be considered a transition phase between magmatic and hydrothermal phases. It may give insight into the dissolution process of magmatic phosphates, help in processing reconstruction, and allow to decipher mineral interactions with hydrothermal fluids