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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.
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.
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Magnetic Polymer Nanocomposite for Medical Application

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EN
Magnetic sponges derived from biocompatible and resorbable polymers are promising materials for medical applications. These materials have been utilised extensively in research applications for the capture of biomolecules and cells, the construction of tissue scaffolds and in regenerative medicine. The object of this study was a polymer scaffold made of polycaprolactone (PCL) containing a 10 wt% amount of nanomagnetite, manufactured in a two-step method. The porosity and morphological parameters were characterised with the use of μ-computer-aided tomography and scanning electron microscopy. Furthermore, the magnetic properties were evaluated. The obtained results confirmed high porosity and the appearance of randomly oriented pores. Moreover, evaluations of the magnetic properties, of both the magnetite nanopowder and the prepared magnetic nanocomposite, were performed. The tests verified the ferromagnetic character of the materials under investigation.
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.
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.
EN
The single cell gel electrophoresis method, known as comet assay, is a rapid and sensitive technique for testing novel chemicals and nanoparticles for genotoxicity, monitoring environmental contamination with genotoxins and human biomonitoring. In our studies we check the applicability of this method for the evaluation of biocompatibility of modified (MWNF) and non-modified multi-walled carbon nanotubes (MWNT) as well as potential genotoxicity of mercury(II) nitrate. The obtained results enabled us to conclude that the presence of Hg(NO₃)₂ (p<0.001) and MWNT (p<0.04) cause a significantly higher level of DNA damage in comparison to functionalised nanomaterials MWNF. It was implied that for the three investigated agents only mercury significantly enhanced genotoxic effect of X-ray exposure (p<0.001) and inhibition of radio-induced DNA damage repair. On the contrary, the presence of MWNF have no influence on cellular repair efficiencies, while incubation with MWNT causes apoptosis and consequently results in lack of attached cells. In conclusion, our results confirmed the genotoxicity of mercury and non-modified carbon nanotubes as well as the biocompatibility of modified nanotubes. Additionally, we proved the usefulness of comet method for the evaluation of genotoxicity and DNA repair under the influence of different compounds and nanomaterials.
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EN
Carbon nanoforms due to their unique properties can be applied in many areas also in medicine. This article presents preliminary genotoxicity studies of electrospun carbon nanofibers (ECNF). This material, apart from its numerous applications, may also be a candidate for use in medical therapy and diagnostics. Polyacrylonitrile (PAN) nanofibers received in the electrospinning process were carbonized and thereafter subjected to oxidation treatment (ECNF-F). Both types of fibres were analyzed with regard to genotoxic influence on the fibroblast line cells using comet assay. Additionally, comet assay experiments were conducted on biocompatible carbon nanotubes with a hydrophilic surface. The results indicate the key role of the oxidation process in the functionalization of carbon nanoparticles intended for medical purposes.
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