Wyniki wyszukiwania - BazTech

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Rusztowania (scaffolds) stosowane w medycynie regenaracyjnej

Chaberska A., Rosiak P., Kamiński Z. J., Kolesińska B.

Wiadomości Chemiczne

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2017

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[Z] 71, 3-4

263--286

EN

The presence of three dimensional support is indispensable condition for successful regeneration of the tissue. In the absence of natural scaffold, or absence of its artificial substitute, regeneration is not possible. The advantage of natural building blocks to create new scaffolds results from the requirements of the materials structures used for tissue regeneration: biocompatibility, biodegradability, lack of cytotoxicity and desirable mechanical properties. Application of these building blocks for the preparation of three dimensional materials should ensure completely biocompatibility of the temporary extracellular matrix equivalent, thus offering construct resembling a natural milieu for the cells and finally regeneration of tissues. These include framework with elements stimulating adhesion of in vitro grown cells, growth factors, hormones and vitamins offered as a completed ingredients in the commercially available culture media. 3D frameworks applied for cell growing should facilitate formation of required tissue shape and size as well as appropriate functioning of the cells. The key factor for the successful regeneration of tissues is the function of the scaffold determining the environment for growing cells, directing proliferation and regulating differentiation processes. The basic feature of the cellular scaffold, determining its functioning is porosity. Pore diameter and their abundance consists a critical factor for penetration of cells into the interior of the implant and finally for successful regeneration of damaged tissue. The progress of tissue regeneration in vitro depends on the presence of cytokines and growth factors, which are controlling cell differentiation process. Nowadays neither of implant material offered on the market has a property comparable to the natural tissue. However, there are many reports presenting preliminary experiments conducted towards attaining novel supports for regenerative medicine derived from peptides and formed by their self-organization. The most advanced of them are known under trade name PuraMatrix, which recently were applied for the regeneration of soft tissues. However, due to tendency of this materials for hydrogels formation, characteristic for them are disadvantageous mechanical properties. The alternative approach based on application of native ECM proteins was also taken into consideration. The weak points of this materials are the susceptibility of proteins towards proteolytic enzymes and theirs immunogenic properties. The diversity of peptide modules give the opportunity to design and synthesize a variety of biomaterials that mimic the structural complexity of the natural ECM.

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Functionalized cellulose as a matrix for the synthesis of library of molecular receptors useful for screening of compounds with anti-histamine activity

Walczak M. E., Frączyk J., Kamiński Z. J., Kolesińska B.

Engineering of Biomaterials

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2017

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Vol. 20, no. 142

2--6

EN

The library of molecular receptors was formed by self-organization of N-heptanoylated dipeptides anchored in the regular fashion via aminophenylamino- 1,3,5-triazine linker to the surface of cellulose membrane. SPOT method was used for the synthesis of peptide library. As C-terminal amino acids of peptide fragments were attached: Ala, Pro and Phe, while as a N-terminal amino acids were applied all natural amino acids. DMT/NMM/TosO- was selected as a coupling reagent for synthesis of library of N-heptanoylated dipeptides. These constructs were used as a tool for distinguishing pharmaceutically active compounds acting on histamine receptors. In the studies as active compounds were tested: Doxylamine and Difenhydramine with histamine agonist activity, Ranitidine and Cimetidine with antagonist activity as well as Histamine – natural ligand. The binding of colourless ligands was monitored by staining with Brilliant Black used as reporter dye and quantitative colour measurement was performed in 256 grade gray scale by using Image-Quant software. Substantial differences in the ability of interactions of agonists and antagonists with bounding pockets were observed with selected molecular receptors. From 60 elements library of molecular receptors were selected 12, which were able to distinguish between agonists or antagonists. It has been found that even small changes (Leu residue vs Val residue) in the structure of molecular receptor influenced specificity of agonist or antagonist binding.

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Od białek amyloidogennych do nanostruktur tworzonych przez proste peptydy

Rożniakowski K. K., Kamiński Z. J.

Wiadomości Chemiczne

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2010

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[Z] 64, 7-8

645-671

EN

Molecular self-assembly offers unique opportunity for the fabrication of novel supramolecular structures and advanced materials. The inspiration for the development of such structures is often resulting from self-assembling modules in biology, as natural systems always form complex structures from relatively simple building blocks [1, 2]. Several studies had demonstrated the versatility of peptide to form well organized assemblies. This includes cyclic peptides designed with alternating D- and L-amino acids, amphiphile peptides, peptide-conjugates and ionic self-complementary peptides. The 37-residue amylin (Fig. 5), also known as islet amyloid polypeptide, forms fibrils that are the main component of amyloid that develops in the pancreas of type 2 diabetes patients. Amylin also in vitro readily forms amyloid fibrils that are highly polymorphic under typical experimental conditions [21-33]. The molecular structure of amylin protofilaments in striated ribbons closely resembles the protofilament in amyloid fibrils with a similar morphology formed by the 40-residue beta-amyloid peptide that is associated with Alzheimer's disease [48-54]. But not only amylin is a self-assembling peptide. We can also find another examples in biological proteins and peptides that have the intrinsic ability to selfassemble into elongated solid nanofibrils, which may give rise to amyloid diseases or alternatively, inspire applications ranging from tissue engineering to nanoelectronics (Fig. 4). Proteinaceous fibrils are extensively studied searching for detailed theoretical models explaining the mechanism of formation, morphology and properties of self-assembled structures. Especially intriguing state of protein-like selfassemblies are nanotubes (NTs), defined as an elongated nano-object with a definite inner hole. In contrast to proteinaceous fibrils, nanotubes are much less frequently observed and far less well understood. However, they have attracted research interest as key components for nanotechnology (Fig. 13). The simplest objects prone to self-assembly are aromatic dipeptides diphenylalanine, diphenylglycine, and their simple derivatives form nanotubes or spherical nanometric assemblies. Remarkable flexibilities of peptides fragments in formation of nanostructures recently have been considered important for many applications in various fields including molecular electronics, tissue engineering, and material science [87-92].

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Asymmetric p(O)-pi(Triazine) Conjugation in the Formally Symmetric Bis(4,6-dimethoxy-1,3,5-triazinyl) Ether in Its Crystal Structure

Główka M. L., Błaszczyk M., Olczak A., Kamińska J. E., Kamiński Z. J.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 12

2163-2172

EN

Reported is the crystal structure of a formally symmetric bis(s-triazinyl) ether obtained as a by-product in the acylation reaction of less reactive nucleophiles with 2-acyloxy-4,6-dimethoxy-1,3,5-tri azines. The title ether shows conformational asymmetry evi - denced by different orientations of the four methoxy groups and the two aromatic rings in relation to the central etheric plane. Differentiation of the two O–C(triazine) bond lengths of the bis(triazinyl) ether can be correlated with the angles between s-triazine rings with the central etheric plane, indicating different degree of conjugation of the two pi-systems with alone pair of the central oxygen atom. It seems that primary reason for the observed asymmetry is crystal packing, causing different orientations of methoxy groups, which in turn induced bond lengths alternation in the s-triazine rings affecting their conjugations with central O atom through AGIBA effect. The experimental obser - vations are in agreement with ab in itio calculation.

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Transformation of Tertiary Amines into Alkylating Reagents by Treatment with 2-Chloro-4,6-dimethoxy-1,3,5-triazine. A Synthetic Application of Side-Reaction Accompanying Coupling by Means of 4-(4,6-Dimethoxy-[1,3,5]triazin-2-yl)-4-methyl-morpholin-4-ium

Kolesińska B., Kamiński Z. J.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 11

2115-2123

EN

Mild reaction conditions are described for the preparation of a number of alkyl chlorides and 2-dialkyl(aryl)amino-4,6-dimethoxy-1,3,5-triazines by dealkylation of quaternary triazinylammonium chlorides formed as reactive intermediates in reaction of tertiary amines with 2-chloro-4,6-dimethoxy-1,3,5-triazine. The high selectivity of substitution was observed within the reactivity order of the alkyl groups: benzyl ~ allyl > methyl > n-alkyl. Studies on dealkylation of S-(-)-dimethyl-(1-phenylethyl)amine to R-(+)-1-chloro-1-phenylethane revealed that reaction proceeded with an inversion of configuration on the carbon atom as may be expected for SN2 type substitution. The scope of reaction was extended by exchange of anion in quaternary triazinylammonium chlorides with I-, SCN-, C6H5O-, CH3COO- followed by N-dealkylation step.

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Structural Basis for Superiority of N-Methyl-N-(4,6-dimethoxy-1,3,5-triazin-2-yl)morpholinium Tetrafluoroborate as Modular Coupling Reagent. Crystal Structures of N-Methyl-N-(4,6-dimethoxy-1,3,5-tri azin-2-yl)morpholinium and -piperidinium Tetrafluorobor

Olczak A., Błaszczyk M., Główka M. L., Kolesińska B., Kamiński Z. J.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 7

1413-1413

EN

Structural characteristics of tetrafluoroborates of N-methylated N-(4,6- dialkoxy- 1,3,5- triazin-2-yl)-morpholine and -piperidine, as determined by X-ray diffraction study, not only explain their good performance as modular coupling reagents in the peptide synthesis but also their higher stability than appropriate chlorides, which degrade easily through demethylation. Not expected axial orientation of 4,6-dialkoxy-1,3,5-triazinyl substituent at the quaternary N atom of the aliphatic ring observed in the crystal state has been confirmed in a solution by NMR technique. Quarternary triazinyl ammonium salts have been found as excellent modular coupling reagents, particularly in peptide syntheses. Crystal structure determination of N-methyltriazinylmorpholinium and -piperidinium tetrafluoroborates as well as their demethylated products provides a structural reason for the observed reaction. Namely, formation of very stable guanidine system around C(2) atom in 2-morpholine- and 2-piperidine-s-tri azines is controlled thermodynamically, while the difference in stability of chlorides and tetrafluoroborates (being superior) of quarternary N-methyl-N-triazinylmorpholinium (or piperidinium) results from conservative conformation of their cations, which hinders an a cess of large and less nucleophilic tetrafluoroborate an ion than Cl– to the methyl carbon atom.

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Sterowanie procesami suburbanizacji w obszarze wzajemnych oddziaływań Katowic i Krakowa. Spojrzenie z perspektywy Katowic

Kamiński Z. J.

Czasopismo Techniczne. Architektura

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2005

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R. 102, z. 15-A

95--101

PL

Charakterystycznymi dla współczesnych zachodnich społeczeństw są zjawiska globalizacji i decentralizacji. W ich kontekście bardziej stanowczo musi być obecnie stawiane pytanie o przyszłą formę miast, a także modele zdolne osiągać zrównoważony rozwój w sposób akceptowalny politycznie, bo chociaż koncepcja zwartego miasta jest traktowana przez planowanie przestrzenne od jego zarania jako ciągle aktualna, to jednak istnieją wątpliwości, czy ludzie rzeczywiście chcą żyć w bardziej zwartych wspólnotach, w większym skupieniu i środowiskach o wyższej intensywności użytkowania terenu. Myślenie o modelu zwartego miasta skłania także do stawiania pytania o przyszły model zagospodarowania regionu, który byłby zdolny sprostać wyzwaniom XXI wieku i wzrastającej globalnej konkurencji.Wszystkie te pytania i wątpliwości odnoszone do sytuacji Aglomeracji Górnośląskiej prowokują do refleksji nad przyszłym modelem Śląskiego Obszaru Metropolitalnego i Europolu Śląsko-Krakowskiego, a w tym szczególnie kierują uwagę na możliwości sterowania procesami suburbanizacji w obszarze wzajemnych oddziaływań Katowic i Krakowa.

EN

Characteristic for the contemporary Western societies are the phenomena of globalization and decentralization. In their context, the question must be posed about the future form of cities and about the models capable of attaining sustainable development in a politically acceptable way. Although the concept of a compact city has been treated by spatial planning as present since its dawn, yet there are some doubts whether people really want to live in more dense communities, in bigger concentration of population and environment with higher intensity of the land use. Thinking about the model a compact city also induces the question about the future model of the development of the region, which could meet the challenge of 21st century and increasing global competition.All these questions and doubts referring to the situation of the Upper Silesian Agglomeration provoke reflection on the future model of the Silesian Metropolitan Area and Cracow-Silesian Europole, particularly focusing on possibility of controlling suburbanization processes in the area of mutual impact of Katowice and Cracow.