Papers by Wojciech Kwiatek
Nucleic Acids Research, 2019
The integrity of the chromatin structure is essential to every process occurring within eukaryoti... more The integrity of the chromatin structure is essential to every process occurring within eukaryotic nuclei. However, there are no reliable tools to decipher the molecular composition of metaphase chromosomes. Here, we have applied infrared nanospectroscopy (AFM-IR) to demonstrate molecular difference between eu- and heterochromatin and generate infrared maps of single metaphase chromosomes revealing detailed information on their molecular composition, with nanometric lateral spatial resolution. AFM-IR coupled with principal component analysis has confirmed that chromosome areas containing euchromatin and heterochromatin are distinguishable based on differences in the degree of methylation. AFM-IR distribution of eu- and heterochromatin was compared to standard fluorescent staining. We demonstrate the ability of our methodology to locate spatially the presence of anticancer drug sites in metaphase chromosomes and cellular nuclei. We show that the anticancer 'rule breaker' plat...
Scientific Reports, 2019
Understanding the response of cancer cells to ionising radiation is a crucial step in modern radi... more Understanding the response of cancer cells to ionising radiation is a crucial step in modern radiotherapy. Raman microspectroscopy, together with Partial Least Squares Regression (PLSR) analysis has been shown to be a powerful tool for monitoring biochemical changes of irradiated cells on the subcellular level. However, to date, the majority of Raman studies have been performed using a single spectrum per cell, giving a limited view of the total biochemical response of the cell. In the current study, Raman mapping of the whole cell area was undertaken to ensure a more comprehensive understanding of the changes induced by X-ray radiation. On the basis of the collected Raman spectral maps, PLSR models were constructed to elucidate the time-dependent evolution of chemical changes induced in cells by irradiation, and the performance of PLSR models based on whole cell averages as compared to those based on average Raman spectra of cytoplasm and nuclear region. On the other hand, predicti...
Physical Review A, 2019
For incident x-ray energies below the core level ionization threshold, one-photon absorption (OPA... more For incident x-ray energies below the core level ionization threshold, one-photon absorption (OPA) leads to off-resonant x-ray excitations that are mediated by a virtual intermediate electronic state. In the linear regime of x-ray interaction, this intermediate state may decay radiatively and the maximum energy of the emitted photon is given by the initial and final atomic state as well as the energy of the incident photon. In the nonlinear excitation regime, however, this intermediate state may be depleted by a second x-ray absorption process as described in the sequential two-photon absorption (TPA) mechanism. Since the same intermediate state is involved in the OPA and TPA processes, the cross-section values for OPA and TPA are interconnected. We report on the determination of cross-section values for off-resonant excitation conditions, and show how the data can be used for estimating the TPA cross section in the sequential absorption mechanism. The determined off-resonant cross sections for cobalt exhibit a Lorentz-like energy-dependent behavior allowing for an energy-dependent description of the OPA and TPA cross sections with semiempirical models. The dependence of TPA cross sections on atomic number is discussed and different scaling laws are investigated. The effect of the lifetimes of a virtual intermediate state is also studied in relation to the incidence x-ray energy.
Folia medica Cracoviensia, 2011
Augmented reality for image guided therapy (ARIGT) of kidney tumor during nephron sparing surgery... more Augmented reality for image guided therapy (ARIGT) of kidney tumor during nephron sparing surgery (NSS): animal model and clinical approach brought to you by CORE View metadata, citation and similar papers at core.ac.uk
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, Nov 1, 2017
Aortic valve is a part of the heart most frequently affected by pathological processes in humans ... more Aortic valve is a part of the heart most frequently affected by pathological processes in humans what constitute a very serious health problem. Therefore, studies of morphology and molecular microstructure of the AV are needed. mSR-FTIR spectroscopy and microscopy represent unique tools to study chemical composition of the tissue and to identify spectroscopic markers characteristic for structural and functional features. Normal AV reveals a multi-layered structure and the compositional and structural changes within particular layers may trigger degenerative processes within the valve. Thus, deep insight into the structure of the valve to understand pathological processes occurring in AV is needed. In order to identify differences between three layers of human AV, tissue sections of macroscopically normal AV were studied using mSR-FTIR spectroscopy in combination with histological and histochemical stainings. Tissue sections deposited onto CaF 2 substrates were mapped and representative set of IR spectra collected from fibrosa, spongiosa and ventricularis were analysed by Principal Component Analysis (PCA) in the spectral range between 1850-1000 cm À1 and 3050-2750 cm À1. PCA revealed a layered molecular structure of the valve and it was possible to identify IR bands associated to different tissue parts. Spongiosa layer was well differentiated from other two layers mainly based on IR bands characteristic for the distribution of glycosaminoglycans (GAGs) in the tissue-like 1170 cm À1 (t as (C-O-S)) and 1380 cm À1 (acetyl amino group). Additionally, it was distinguished from fibrosa and ventricularis based on 1085 cm À1 and 1240 cm À1 bands characteristic for GAGs and for carbohydrates-m(C-O) and m(C-O-C) respectively and nucleic acids-m sym (PO 2 À) and m asym (PO 2 À) respectively, which were less specific for this layer. The use of mSR-FTIR spectroscopy demonstrated co-localization of GAGs and lipids in spongiosa layer what may indicate their contribution in the very early phase of aortic valve calcific degeneration.
Angewandte Chemie, Nov 15, 2013
Individual Double Strand Breaks (DSBs) were first detected and located by AFM and then the molecu... more Individual Double Strand Breaks (DSBs) were first detected and located by AFM and then the molecular structure of this damage was characterized with Tip Enhanced Raman Scattering (TERS) using a topdown configuration and reflective substrate. Here we report the first experimental evidence proving that individual DSBs result from cleavage at the 3'-and 5'-bonds of deoxyribose upon exposure to UVC radiation based on the observation of P-O-H and methyl/methylene deformation modes enhanced in the TERS spectra. We hypothesise that strand fragments are hydrogen-terminated at the lesion, indicating the action of free radicals during photon exposure.
Polish Journal of Environmental Studies, 2007
This paper presents the results of determination of artificial 137 cs and natural 40 k activity c... more This paper presents the results of determination of artificial 137 cs and natural 40 k activity concentrations and some heavy metals in soil samples from the region of one of the main valleys of Tatra national Park (Chochołowska). our investigation concentrated on 137 Cs and heavy metal levels in mountain soil taken from Chochołowska Valley, which revealed great variability in their concentration. The results show considerably small amounts of radionuclides 137 cs and 40 k in the soils. larger amounts of those elements can be found in the organic surface horizons of the soils. The evaluation of the content of those elements must be based on the bulk density analysis of the soil.
International Journal of Molecular Sciences
The uptake and distribution of doxorubicin in the MCF7 line of breast-cancer cells were monitored... more The uptake and distribution of doxorubicin in the MCF7 line of breast-cancer cells were monitored by Raman measurements. It was demonstrated that bioavailability of doxorubicin can be significantly enhanced by applying Congo red. To understand the mechanism of doxorubicin delivery by Congo red supramolecular carriers, additional monolayer measurements and molecular dynamics simulations on model membranes were undertaken. Acting as molecular scissors, Congo red particles cut doxorubicin aggregates and incorporated them into small-sized Congo red clusters. The mixed doxorubicin/Congo red clusters were adsorbed to the hydrophilic part of the model membrane. Such behavior promoted transfer through the membrane.
Acta Biochimica Polonica
The proper diagnosis is a critical factor to reduce further disturbances at the early stage of th... more The proper diagnosis is a critical factor to reduce further disturbances at the early stage of the disease and plays an important role in increasing the success rate of the therapy. The traditional diagnostic tools such as biopsy or blood collection are always associated with patient’s discomfort, the possibility of infections and time-consuming procedures. This article describes the non-invasive and easily accessible saliva as a source of numerous molecular biomarkers. The salivary fluid can provide information about the pathological changes not only in the oral area but also in other parts of the body, therefore salivary tests may be promising tools for risk prediction and treatment monitoring of many disorders.
Biophysical Journal, 2018
Scientific Reports, 2021
Head and neck tumors can be very challenging to treat because of the risk of problems or complica... more Head and neck tumors can be very challenging to treat because of the risk of problems or complications after surgery. Therefore, prompt and accurate diagnosis is extremely important to drive appropriate treatment decisions, which may reduce the chance of recurrence. This paper presents the original research exploring the feasibility of Fourier transform infrared (FT-IR) and Raman spectroscopy (RS) methods to investigate biochemical alterations upon the development of the pleomorphic adenoma. Principal component analysis (PCA) was used for a detailed assessment of the observed changes and to determine the spectroscopic basis for salivary gland neoplastic pathogenesis. It is implied that within the healthy margin, as opposed to the tumoral tissue, there are parts that differ significantly in lipid content. This observation shed new light on the crucial role of lipids in tissue physiology and tumorigenesis. Thus, a novel approach that eliminates the influence of lipids on the elucidati...
Acta Physica Polonica A, 2018
Preliminary studies on the sediments collected from water meters of Krakow water supply system we... more Preliminary studies on the sediments collected from water meters of Krakow water supply system were performed in the cooperation with the Municipal Water Supply and Sewage. Creation and deposition of sediments on the measuring devices installed in the water supply system is a serious technological and economical problem for water companies, defectively operating for this reason water meters must be replaced. It is evident that knowledge of the chemical and phase composition of sediments is an important step towards resolving the problem of impurities in water supply systems. Four different samples of sediments, coming from water meters, were investigated using the proton-induced X-ray emission, the X-ray diffraction, the Fourier transform infrared and Raman spectroscopy. The X-ray methods revealed presence of amorphous and fine-crystalline phases as well as high content of iron-based compounds. As a crystalline phase, the most frequently appeared: goethite, lepidocrocite, iron oxides (hematite, maghemite, magnetite), calcium carbonate, and quartz. In one of the samples, the nanocrystalline phase was found and identified as hydrous iron oxyhydroxide ferrihydrite. Vibrational spectroscopy methods confirmed the composition of crystalline phases as well as enabled to estimate the abundance of amorphous phase in samples.
Nature Communications, 2020
OLED technology beyond small or expensive devices requires light-emitters, luminophores, based on... more OLED technology beyond small or expensive devices requires light-emitters, luminophores, based on earth-abundant elements. Understanding and experimental verification of charge transfer in luminophores are needed for this development. An organometallic multicore Cu complex comprising Cu–C and Cu–P bonds represents an underexplored type of luminophore. To investigate the charge transfer and structural rearrangements in this material, we apply complementary pump-probe X-ray techniques: absorption, emission, and scattering including pump-probe measurements at the X-ray free-electron laser SwissFEL. We find that the excitation leads to charge movement from C- and P- coordinated Cu sites and from the phosphorus atoms to phenyl rings; the Cu core slightly rearranges with 0.05 Å increase of the shortest Cu–Cu distance. The use of a Cu cluster bonded to the ligands through C and P atoms is an efficient way to keep structural rigidity of luminophores. Obtained data can be used to verify comp...
Journal of Biophotonics, 2020
The family of vibrational spectroscopic imaging techniques grows every few years and there is a n... more The family of vibrational spectroscopic imaging techniques grows every few years and there is a need to compare and contrast new modalities with the better understood ones. Three vibrational spectroscopy techniques (High Definition FT‐IR, Raman and AFM‐IR) were applied for subcellular chemical imaging of cholesteryl esters in PC‐3 prostate cancer cells. The techniques were compared and contrasted in terms of image quality, spectral pattern, and chemical information.Further details can be found in the article by Maciej Roman, Tomasz P. Wrobel, Czeslawa Paluszkiewicz, and Wojciech M. Kwiatek (e201960094). image
Scientific Reports, 2020
An amendment to this paper has been published and can be accessed via a link at the top of the pa... more An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RSC Advances, 2019
Correction for ‘Mid-infrared spectroscopy and microscopy of subcellular structures in eukaryotic ... more Correction for ‘Mid-infrared spectroscopy and microscopy of subcellular structures in eukaryotic cells with atomic force microscopy – infrared spectroscopy’ by Luca Quaroni et al., RSC Adv., 2018, 8, 2786–2794.
Journal of Spectroscopy, 2019
In this study, we provide the first Fourier-transform infrared absorption spectroscopy (FTIR) and... more In this study, we provide the first Fourier-transform infrared absorption spectroscopy (FTIR) and Raman spectroscopy (RS) analysis of a vibrational fingerprint of erlotinib, a drug which is applied in non-small cell lung cancer therapy, in solid state and solution in different pH conditions. Additionally, the performed DFT theoretical calculations in vacuum and PCM models support the interpretation of vibrational spectra and give insight into an optimized spatial configuration of the investigated drug. The present considerations show vibrational structure of erlotinib and details of its molecular geometry. Furthermore, we discuss the pH condition where the protonated –NH+ and C=N+ forms occur and indicate the spectral changes characteristic for the erlotinib protonation. It is of great of importance to better understand biological activity of the drug and to develop new tyrosine kinase inhibitors.
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Papers by Wojciech Kwiatek