Fulin P.,I. ortopedicka klinika 1 |
Pokorny D.,I. ortopedicka klinika 1 |
Slouf M.,Ustav makromolekularni chemie AV CR |
Lapcikova M.,Ustav makromolekularni chemie AV CR |
And 2 more authors.
Acta Chirurgiae Orthopaedicae et Traumatologiae Cechoslovaca | Year: 2011
PURPOSE OF STUDY Aseptic loosening of total joint replacement (TJR) due to wear of ultra-high molecular weight polyethylene (UHMWPE) is regarded as one of the major problems in the field of arthroplasty. This work describes a newly developed method, called MORF, which completely describes the morphology of UHMWPE wear particles. The differences in wear particle morphology may help to elucidate individual differences in TJR failures. MATERIAL AND METHODS During the years 2002-2010, a set of 47 typical damaged periprosthetic tissues, coming from 16 TJR revisions, was collected. Isolated on polycarbonate (PC) filters were quantified. Quantification of the particles consisted in determination of their concentration and description of their morphology by means of the newly developed MORF method. Firstly, the micrographs of isolated UHMWPE particles were obtained with a scanning electron microscope (Quanta 200 FEG; FEI) at two magnifications: x1200 and x6000. Secondly, both high- and low-magnification micrographs were processed by a standard image analysis software (program NIS Elements; Laboratory Imaging) in order to obtain basic morphological descriptors. Finally, the results from image analysis of high- and low- magnification micrographs were combined by means of our own program MDISTR in order to obtain correct particle sizes and shapes. RESULTS In the first stage, the method was applied to 25 samples and yielded an average particle size of 0.51 μm. In the second stage, the method was further improved in order to calculate not only the size of particles but also the shape of descriptors. The improved method was applied to eight samples and gave an average size of particles (equivalent diameter, D) in the range of 0.27 - 0.60 μm, circularity (C) of 0.66-0.85 and elongation (E) of 1.75-1.79, suggesting that the great majority of particles were approximately spherical. Finally, in the third stage, the MORF method was applied to two exceptional samples which contained extremely small wear particles (D = 18.5 nm and 21.2 nm). The shape of these small wear nanoparticles (C = 0.97 and 0.93; E = 1.29 and 1.35) was even more spherical than that of wear microparticles described above. This was one of the first two studies which proved the presence of UHMWPE wear nanoparticles in vivo. DISCUSSION Our newly developed MORF method described in this contribution yields both size and shape descriptors of UHMWPE wear particles, with sizes from 0.1 to 10 μm, which are regarded as most biologically active. The main objective of the method is to yield the highest accuracy. This is achieved by parallel analyses of high- and low-magnification micrographs taken of the same sample. In the end, the two analyses are combined together in order to obtain the correct and complete size and shape description of all particles in the sample. The morphology of UHMWPE wear particles influences TJR lifetime both directly (size and shape of the particles is related to their biological activity) and indirectly (for the given total volumetric wear, size and shape of the particles influence their concentration, which is associated with the biological response of the organism). CONCLUSION The authors have developed a new method which yields a complete description of the size and shape of UHMWPE wear particles in periprosthetic tissues. The method, which was called MORF, can be applied to studies of TJR failures and also used to evaluate the quality of different UHMWPE components of TJR. The method is quite universal and therefore can be used not only for analyses of wear particles, but also for other types of particles, such as microparticles in polymer blends or inorganic/metallic nanoparticles.
Blazkova I.,Mendel University in Brno |
Ryvolova M.,Mendel University in Brno |
Ryvolova M.,Stredoevropsky Technologicky Institute |
Krizkova S.,Mendel University in Brno |
And 10 more authors.
Klinicka Onkologie | Year: 2013
Anthracycline cytostatics can be observed at the level or organelles, cells and whole organisms due to their fluorescent properties. Imaging techniques based on detection of fluorescence can be used not only for observation of drug interaction with tumor cells, but also for targeting therapy of tumors with nanoparticles containing anthracycline cytostatics. Doxorubicin and daunorubicin, enclosed in liposomes, as representatives of nanoparticles suitable for targeted therapy, are used in clinical practice. The main advantage of liposomal drugs is to reduce the side effects due to differences in pharmacokinetics and distribution of the drug in the body. Due to the fact that all biological mechanisms of action of anthracycline drugs are not still fully understood, modern imaging techniques offer tool for in vivo studies of these mechanisms.
Heger Z.,Mendel University in Brno |
Eckschlager T.,Klinika Detske Hematologie a Onkologie 2 |
Stiborova M.,Katedra biochemie |
Adam V.,Mendel University in Brno |
And 2 more authors.
Klinicka Onkologie | Year: 2015
Backgrounds: Despite the fast development of new effective cytostatics and targeted therapy, the treatment efficiency of lung cancer is still insufficient. The systemic administration of drugs results in a decrease in drug concentrations in tumor site, particularly due to specific extracellular environment in lungs. Nanotransporters could serve as a platform, protecting a drug against these undesired effects, which may enhance its therapeutic index and reduce side effects of a drug. Moreover, nanotechnologies possess the potential to improve the diagnostics of lung cancer, and thus increase a survival rate of oncologic patients. Aim: The presented study is aimed to demonstrate the possibilities provided by nanotechnologies in the field of treatment and diagnostic of lung cancers and discuss the obstacles, which complicate a translation into clinical practice.
Adamkova S.,Katedra biochemie |
Petrivalsky M.,Katedra biochemie
Chemicke Listy | Year: 2012
This review summarizes the current knowledge of metabolism and function of polyamines and signaling molecules of NO in plants. Polyamines (PA) interact with polyanionic biomolecules such as DNA or some proteins and appear to be involved in a wide range of plant processes. Despite their significance, the polyaminedependent signal transducer system has not yet been found. It has been shown that PA induce NO biosynthesis in plants. PA seem to be mediators in pathogen defence, abiotic stresses and senescence.
Moricova P.,Katedra biochemie |
Luhova L.,Katedra biochemie |
Lochman J.,Ustav biochemie |
Kasparovsky T.,Ustav biochemie |
Petrivalsky M.,Katedra biochemie
Chemicke Listy | Year: 2014
Elicitors, endogenous compounds produced by microbial pathogens, induce defence responses in plants. They rank among chemically nonuniform groups including proteins, glycoproteins, oligo- and polysaccharides and lipids. By multiple mechanisms, elicitors are capable of triggering various modes of plant defence like oxidative burst, hypersensitive response, increased expression of pathogenesis-related proteins and the production of antimicrobial compounds - phytoalexins. Elicitins, secreted by oomycetes from Phytophthora and Pythium spp., are small (10 kDa) protein elicitors structurally similar to lipid-transfer proteins of plant cells and behaving like sterol carrier proteins. In the host plant, elicitins induce a hypersensitive response and development of acquired systemic resistance to many microbial phytopathogens. The review summarizes the current knowledge of the molecular modes of elicitin interaction with plant cells, with a special emphasis on cryp-togein as a model elicitin for potential application in the induction of systemic plant resistance. © 2014 Czech Society of Chemical Engineering. All Rights reserved.
Simsikova M.,Katedra biochemie |
Antalik M.,Katedra biochemie
Chemicke Listy | Year: 2014
ZnO nanoparticles show a big potential as a fluorescent probes in biological fields, such as bioimaging, biolabeling and biodetection because of their unique optical properties. However, their surface modification is necessary for application in biosystems. We prepared 40-50 nm ZnO nanoparticles functionalized with thioglycolic acid (TGA) for applications in biosystems. The capping with the thiol acid was confirmed by zeta potential measurements and FT-IR spectroscopy. UV-vis and photoluminescence spectroscopies confirmed the effect of modification as well.
Raus M.,Katedra biochemie |
Kopecny D.,Katedra biochemie |
Sebela M.,Katedra biochemie
Chemicke Listy | Year: 2013
Here we introduce the Protein Cutter (http://biochemie.upol.cz/software/proteincutter), a web application for the prediction of results of protein digestion by proteolytic enzymes, which is accessible over the Internet network. In the beginning, previous and current approaches for protein sequencing are summarized. This includes the use of dinitrofluorobenzene and substituted isothiocyanate reagents as well as mass-spectrometry-based strategies and translation of genomic sequences. The following text characterizes bioinformatics as a modern scientific discipline, which solves problems arising from the management and analysis of biological data. The most important nucleotide and amino acid sequence databases are described together with the databases of DNA and protein structures. The program Protein Cutter, which is described in detail with respect to its design and technology, allows predicting peptide sequences generated by proteolytic digestion of a protein (represented by a user-entered amino acid or coding nucleotide sequence). In addition to other comparable applications, Protein Cutter offers more complex information calculated from amino acid sequences (i.e. molecular mass, amino acid composition, isoelectric point, hydropathicity index etc.), it works with nucleotide sequences upon automatic translation, it is open and friendly for user-entered cutting rules and provides more options for the filtration and sorting of results.