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1
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The UV-C Induced Cell Death in Human Malignant Melanoma and Normal Fibroblasts

100%
Panek A., Wiecheć A.
Acta Physica Polonica A
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2016
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vol. 129
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issue 2
172-173
EN
Differences in cellular death between melanoma (Me45) cells and fibroblasts (CCL-110) were investigated after irradiation with UV-C (1.5-15 J/m²) and incubation for up to 48 h. The role of DNA double strand breaks in this process was assessed. Decrease of the Me45 cells viability began about 6 h after irradiation. The fibroblasts viability negatively correlated with the dose applied, since necrosis within this cell population began immediately after irradiation. The enhanced apoptosis of fibroblasts was observed between 6 and 24 h, while for melanoma cells, high level of apoptotic cells was still detected after 48 h. Statistically significant correlation between the percentage of apoptotic cells and DSBs was estimated for both cell lines. The melanoma cells responded differently to the UV-C radiation than did the fibroblasts. These differences were explained by deficiency of the necrotic processes as well as the delay of apoptotic melanoma response to UV-C damage.
2
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Nanocomposite Polymer Scaffolds for Bone Tissue Regeneration

81%
Stodolak-Zych E., Frączek-Szczypta A., Wiecheć A., Błażewicz M.
Acta Physica Polonica A
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2012
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vol. 121
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issue 2
518-521
EN
Nanocomposite polymer scaffolds for tissue engineering were prepared using leaching method. As a porogen there were used phosphate salts with different grain size (100-400 μm). Nanocomposite materials based on polylactide (PL/DLA) containing 2 wt% of ceramic bioactive nanoadditives (SiO_2) were prepared. The nanoadditive was characterized by dynamic light scatering (DLS) (size) and the Brunauer-Emmett-Teller (specific surface area) methods. Morphology of the nanoparticles was observed using the transmission electron microscopy. The optimal concentration of the nanofiller in the polymer matrix was evaluated on the basis of in vitro tests of the nanocomposite foils contacted with osteoblast-like human cells of MG63 line. The morphology and porosity of the scaffold after leaching was evaluated using scanning electron microscopy and hydrostatic weighing. The bioactivity test made on the scaffolds demonstrated ability to nucleation of apatite structure on the material.
3
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Effect of Magnetite Composite on the Amount of Double Strand Breaks Induced with X-Rays

81%
Wiecheć A., Nowicka K., Błażewicz M., Kwiatek W.
Acta Physica Polonica A
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2016
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vol. 129
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issue 2
174-175
EN
The aim of this study was to find out if polylactide (PLA) modified with magnetite might affect the amount of DNA double strand breaks induced with X-rays. The human osteosarcoma cells (MG63) were seeded on the polystyrene cell culture dishes (PS), PLA and PLA modified with magnetite substrates. The double strand breaks were analyzed after X-ray irradiation (dose rate 2 Gy/min), in the first day of culturing. The number of double strand breaks increased in the PLA modified with magnetite, for example after 1 Gy of X-rays irradiation, double strand breaks/cell equaled: 24.5 vs. 17.5 and 17.3, for PLA modified with magnetite vs. PLA and PS, p < 0.0003. We conclude that PLA modified with magnetite changed the number of double strand breaks induced with X-rays. However, more research is needed to confirm that such composite might be considered as radiosensitizer in radiotherapy.
4
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The Study of Human Osteoblast-Like MG 63 Cells Proliferation on Resorbable Polymer-Based Nanocomposites Modified with Ceramic and Carbon Nanoparticles

71%
Wiecheć A., Stodolak-Zych E., Frączek-Szczypta A., Błażewicz M., Kwiatek W.
Acta Physica Polonica A
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2012
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vol. 121
|
issue 2
546-550
EN
Polymer-based nanocomposites containing biocompatible and bioactive nanocomponents seem to be excellent materials that could be used in many biomedical applications. The aim of this study was biological evaluation of resorbable polymer-based nanocomposites (PLA, PCL) and their modifications with ceramic nanoparticles (silica - SiO_2, montmorillonite - MMT) or carbon nanotubes. The nanocomposites were seeded with the human osteoblast-like MG 63 cells. After 1, 3 and 7 days of incubation, Trypan blue exclusion test was used to determine the viability and number of cells. The cell population density depending on incubation time and cell population doubling time was calculated. The cell proliferation abilities on the all applied nanocomposites and on control material (polystyrene cell culture plate) were also compared. The number of cells growing on the nanocomposite surfaces increased with the incubation time. The cell viability was not decreased for all applied materials during the entire study (97-100%). The ceramic nanoparticles and carbon nanotubes modified the bone cell growth and proliferation rate. Results of this study confirm that all types of the nanocomposites are appropriate to the growing and proliferation of human osteoblast-like cells.
5
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FTIR Microspectroscopy in Studies of DNA Damage Induced by Proton Microbeam in Single PC-3 Cells

71%
Lipiec E., Kowalska J., Lekki J., Wiecheć A., Kwiatek W.
Acta Physica Polonica A
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2012
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vol. 121
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issue 2
506-509
EN
In recent years, the Fourier transformed infrared spectroscopy is often applied in studies of biological materials on cellular level. Undoubted advantage of this method is high sensitivity. In presented research the FTIR microspectroscopy was used to analyse the DNA damage in single PC-3 cells (prostate cancer cell line derived from bone metastases) irradiated by counted number of protons. Focused proton microbeam 2 MeV from the Van de Graaff accelerator at the Institute of Nuclear Physics, Polish Academy of Sciences, was used as an irradiation source. Four groups of single cells were irradiated with 1000, 2000, 4000, and 8000 protons per cell, respectively. Following irradiation cells were fixed in 70% ethanol and then analyzed by IR microspectroscopy. Bond analysis of IR spectra served as a base for result analysis. This research has focused on the detection of changes in DNA backbone spectral range (950-1240 cm^{-1}), which could be related to damages such as single and double strand breaks, DNA-DNA, and DNA-protein cross links. Switches and differences in intensity of DNA backbone bands (980-1149 cm^{-1}, 1151-1350 cm^{-1} - symmetric and asymmetric PO^{2-} stretching vibrations, as well as in 1110 cm^{-1} - symmetric stretching of P-O-C band) were observed. Experimental spectra of irradiated and control cells were compared with simulated spectra generated by HyperChem software. The multivariate statistical methods of principal component analysis and hierarchical cluster analysis (Ward's method) were also performed and are discussed.
6
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Titanium Surface Modification with Carbon Nanotubes. Towards Improved Biocompatibility

71%
Benko A., Wiecheć A., Rajchel B., Długoń E., Błażewicz M.
Acta Physica Polonica A
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2016
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vol. 129
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issue 2
176-178
EN
Subject of this study is surface modification of titanium with thin layers of carbon nanotubes, obtained via an electrophoretic deposition, as a means to improve metal's biocompatibility and provide a suitable matrix for very facile further modifications, if needed. Article presents a preliminary evaluation of the material, using goniometer, scanning electron microscopy and the Raman spectroscopy. The layer is found to be composed of randomly distributed, strongly adhered carbon nanotubes, introducing nanotopography to the surface of titanium. Biological studies were conducted with the human osteoblast-like cell line MG63. Biocompatibility of materials was evaluated using: (a) lactate dehydrogenase cytotoxicity test (LDH) and (b) γ -H2AX genotoxicity test (presence of DNA double strand breaks). Results confirmed non-toxic character of the tested materials. Moreover, carbon nanotubes layers enhanced the biocompatibility properties of titanium substrate - material with carbon nanotubes possessed lower cellular toxic properties even than pure titanium. The result of this preliminary study are very promising and may serve as a starting point for further studies, including further chemical or biological modification of the obtained materials.
7
Content available remote

Infrared Spectroscopy in Molecular Study of the Piezoelectric Effect in Pig's Shin Bone

61%
Lipiec E., Kowalska J., Wiecheć A., Zieliński P., Kwiatek W., Iwaniec M.
Acta Physica Polonica A
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2012
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vol. 121
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issue 2
539-542
EN
Despite growing number of literature demonstrating the piezoelectric effect in bones at macro level there's still a lack of papers describing this effect at molecular level. In order to examine this effect more specifically, a study has been conducted to show the possibility of using infrared spectroscopy on samples contained in the electric field. This is the first known research on applying infrared spectroscopy to study the influence of electric field and compressive stress on bones' structure represented by the molecular IR spectrum. The samples used in this experiment as a model were prepared in pellet form, made from powdered pig's shin bone mixed with KBr (mass ratio of about 1:100). The spectra were obtained in transmission mode. Three different types of experiments were performed at each sample, which were subjected to: (a) fixed electric field (E < 40 kV/m), (b) variable electric field (0-40 kV/m), (c) compressive stress (P < 100 MPa). The obtained data have shown that the electric field and compressive stress on sample modified infrared spectra of the bone. Qualitative as well as quantitative changes in the spectral range between 900 cm^{-1} and 1200 cm^{-1} and the band at 562 cm^{-1} (PO_4^{3-} asymmetric and symmetric stretching, respectively) were observed. The relative area obtained by decomposition of the PO_4^{3-} band reaches an extreme value in the external compressive stress (10 MPa), that occur under physiological conditions. Based on presented data, it was proved that the applied factors (electric field, compressive stress) can change the oscillation energy and the number of molecule's degrees of freedom.
8
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Content available

Studies of the Verwey Transition in Magnetite

52%
Tarnawski Z., Wiecheć A., Madej M., Nowak D., Owoc D., Król G., Kąkol Z., Kolwicz-Chodak L., KozŁowski A., Dawid T.
Acta Physica Polonica A
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2004
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vol. 106
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issue 5
771-775
EN
Studies of the specific heat and simultaneous AC magnetic susceptibility (ρ') and electric resistance of stoichiometric magnetite single crystal are presented. The temperature hysteresis of the Verwey transition is of 0.03 K found from the specific heat data confirming its first-order character. The continuous temporal change of ρ' at T_V can be switched off by an external magnetic field without affecting the transition. The electrical resistance decreases continuously with increasing temperature with a rapid change of slope at the point when the phase transition is completed. It was concluded that the magnetic degrees of freedom do not actively participate in the transition and that the entropy released at T_V may come from ordering electrons.
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