The UV-C induced cell death in human malignant melanoma and normal fibroblasts

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

Preliminary investigations of polylactide-based nanocomposites as potential materials for bone cells proliferation

Nanocomposite materials can be used in many application. In this study polymer–based nanocomposites modified with carbon nanotubes (CNTs) and ceramic silica nanoparticles (nSiO2) were used. Size and shape of nanoparticles were observed using transmission electron microscope (TEM). It was shown that, this parameter changes during mixing of nanoparticles with solvent or polymer solution. Dispersion of nanoparticles depends on their chemical composition. The CNTs are more compatible with polymer (PLDL) than nSiO2. Nanoparticles influence rheological parameters of the polymer solution (increase of viscosity). Distribution of nanoparticles within the polymer matrix was determined using DLS method. Nanocomposites in the form of thin foils were used for mechanical tests which show that small amount of nanoparticles increases tensile strength (Rm) and Young’s modulus (E) of the material. The biological properties of the polymer-based nanocomposite materials like viability and proliferation were measured using osteoblast-like human cells MG63. Results of these investigations show that both types of the nanocomposites are suitable for promoting bone tissue for faster regeneration process

Nanocomposite Polymer Scaffolds for Bone Tissue Regeneration

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

Effect of magnetite composite on the amount of double strand breaks induced with X-rays

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

Nanocomposite Polymer Scaffolds for Bone Tissue Regeneration

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

Titanium Surface Modification with Carbon Nanotubes. Towards Improved Biocompatibility

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

FTIR Microspectroscopy in Studies of DNA Damage Induced by Proton Microbeam in Single PC-3 Cells

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

FTIR Microspectroscopy in Studies of DNA Damage Induced by Proton Microbeam in Single PC-3 Cells

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