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Title:Polihipe materiali za rast bioloških celic pripravljeni s tiol-en polimerizacijo
Authors:Sušec, Maja (Author)
Krajnc, Peter (Mentor) More about this mentor... New window
Liska, Robert (Co-mentor)
Files:.pdf DR_Susec_Maja_i2014.pdf (9,56 MB)
 
Language:Slovenian
Work type:Dissertation (m)
Typology:2.08 - Doctoral Dissertation
Organization:FKKT - Faculty of Chemistry and Chemical Engineering
Abstract:Tkivno inženirstvo je tehnika, ki temelji na regeneraciji različnih tipov celic, ki rastejo na ustrezni podlagi. V zadnjem času tkivno inženirstvo in tkivne kulture pridobivajo na pomembnosti zaradi uspešne uporabnosti v biomedicini. Tkivno inženirstvo je zelo uporabno predvsem na področju rasti tkiv, presajanja organov in na področju rekonstruktivne kirurgije. Uporaba ustreznih materialov kot matrik je ključnega pomena za tkivno inženirstvo in tudi pri oblikovanju umetne, zunajcelične matrike (podlage), ki podpira 3D tkivno tvorbo. Polimeri so primarni materiali, ki se uporabljajo za ustrezno podlago na področju tkivnega inženirstva, vključno za rast kosti, hrustanca, krvnih žil, mehurja, kože in drugih tkiv. Gre za uporabo kombinacije celic in materialov ter pripadajočih biokemijskih in fizikalno-kemijskih faktorjev za izvajanje ali nadomestilo bioloških funkcij. Za uspešno rast tkiva in razmnoževanje celic je ustrezna podlaga nujna in tako je tudi zelo pomembno, da kontroliramo morfologijo, porozno strukturo in velikost porazdelitve por ustreznega materiala. Poroznost polimernega materiala je lahko dosežena skozi različne procese, med njimi je emulzija osnova za pripravo poroznih materialov. Poleg omenjenih parametrov je znano, da je rast celic boljša na tridimenzionalni porozni podlagi. Dodatno pa je potrebno upoštevati še biokompatibilnost in biorazgradljivost podlage. Ustrezne nosilce smo pripravili tudi s pomočjo polimerov pripravljenih s pomočjo emulzij. Pripravili smo emulzije z visokim deležem notranje faze, pri čemer volumen notranje faze emulzije presega 74.05 % in tako pripravili poliHIPE materiale, ki so bili uporabljeni tudi kot substrati za tkivno inženirstvo. O poliHIP-ih je glede tkivnega inženirstva poznanega zelo malo. Ponavadi so poliHIPE materiali producirani tekom radikalne verižne polimerizacije in tako biodegradibilnost nastalega materiala lahko predstavlja problem. Klasične metode za procesiranje polimernih materialov kot so ekstruzija ali brizganje so pogosto uporabljene za proizvajanje tipičnih biokompatibilnih in biodegradabilnih materialov kot so poli(mlečna kislina) za izdelavo šivov, materiali za vezavo kosti in materiali za druge medicinske pripomočke. Na žalost pa imajo te tehnike zelo omejene zmogljivost za proizvodnjo celičnih matrik. Alternativna metoda kot je litje topila, izpiranje delcev, penjenje plinov and lepljenje vlaken imajo tudi nekatere omejitve kot so nizka sposobnost za natančno kontrolo velikosti por, geometrije por, medsebojne povezanosti por, prostorsko porazdelitev por in konstrukcijo notranjih poti v matriko (podlago). Eden od pomembnih dosežkov v tkivnem inženirstvu je bil razvoj tridimenzionalnih matrik, ki usmerjajo celice, da tvorijo funkcionalna tkiva. Nedavno poznane proizvodne tehnike poznane kot izdelava prosto oblikovanih površin (Solid Freee Form Fabrication-SFF), ali hitra izdelava prototipov (rapid prototoyping-RP), se uspešno uporabljajo za proizvodnjo kompleksnih matrik. Fotopolimerizabilen metakrilat se uporablja kot večina ostalih monomerov, ki so danes na tržišču oz. kot biokompatibilen in biodegradabilen monomer, ki je pogosta tema raziskav v zadnjem obdobju. Čeprav ima ta material številne prednosti pred PLA (poli mlečna kislina) saj na mehanske lastnosti in degradacijsko obnašanje lahko vplivamo. je kot monomer dražljiv. Zato smo razvili novo generacijo biokompatibilnih in biodegradabilnih fotopolimerov, ki temeljijo na vinilestrih in vinilkarbonatih, ki imajo enake prednosti kot (met)akrilati in se izogibajo večini slabih lastnosti. Poleg enostavne sinteze in zelo nizke monomerne citotoksičnosti, nastanejo nestrupeni razgradni produkti, ki se zlahka izločajo iz človeškega telesa. Prvi in vivo eksperimenti so takšni materiali pokazali odlično biokompatibilnost. Raziskovalno doktorsko delo je bilo osredotočeno tudi na pripravo biokompatibilnih in biorazgradljivih poroznih polimerov preko HIPE in uvedba druge hierarhične ravni v 50-100 µm preko 3D fotopolimerizacije. Preizkuï
Keywords:poliHIPE, tiol-ene kemija, biološke celice, fotopolimerizacija
Year of publishing:2014
Publisher:M. Sušec]
Source:[Maribor
UDC:612.26:577.11(043.3)
COBISS_ID:18307862 Link is opened in a new window
NUK URN:URN:SI:UM:DK:MUHOSQ4V
Views:1481
Downloads:173
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Categories:KTFMB - FKKT
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Secondary language

Language:English
Title:Doctoral Thesis PolyHIPEs for biological cells growth via thiol-ene polymerisations evaluation comitee report
Abstract:Tissue engineering is a technique based on the regeneration of various types of cells which grow on appropriate support and has shown great promise in generating living alternatives for harvested tissues and organs for transplantation and reconstructive surgery. The use of appropriate materials is critically important for tissue engineering in designing artificial extra-cellular matrices (scaffolds), which support three-dimensional tissue formation. Polymers are the primary materials for appropriate supports in various tissue engineering applications, including bone, cartilage, blood vessels, bladder, skin and other tissues. Tissue engineering is the use of a combination of cells and material methods, and suitable biochemical and physio-chemical factors to improve or replace biological functions. For successful growth of tissue and proliferation of cells appropriate support is necessary and it is therefore very important to control the morphology, porous structure and pore size distribution of the supporting material. It is known that the growth of cells proceeds better on three dimensional porous supports. Furthermore, the biocompatibility and biodegradability of the support needs to be taken into account. Different porous polymers with 3D porous struc-ture have been prepared. Porosity of polymeric material can be achieved via different pro-cesses, among them is emulsion templating. Emulsion templating uses the internal phase of the emulsion for the production of large pores in the micrometer range. If the volume space of the internal phase of the emulsion exceeds 74.05 %, the emulsion is termed a high internal phase emulsion. One of the main goals in our PhD work has been the development of 3D scaffolds that guide cells to form functional tissue. Photopolymerisable (meth) acrylate based formulations are frequently used for the preparation of scaffolds since a large variety of monomers is com-mercially available. Biocompatible and biodegradable monomers have frequently been inves-tigated in the last decade. Although these materials have some obvious advantages over PLA (polylactic acid) (tunable mechanical properties and degradation behaviour), monomer irritancy and high molecular polyacrylic acid as degradation product are some serious disad-vantages. Therefore we have developed a new generation of biocompatible and biodegrada-ble photopolymers based on vinylesters, acrylates and thiols that have all the advantages of (meth) acrylates and circumvent most of their drawbacks. Besides easy synthesis and very low monomer cytotoxicity, non-toxic degradation products are formed that can easily been excreted from the human body. Research work of the PhD thesis presents a preparation of biocompatible and biodegradable porous polymers via high internal phase emulsion templating and the introduction of a second hierarchical level in the 50-100 µm range using layer-by-layer macrostructuring. By using monomers such as trimethylolpropantriacrylate (TMPTA; Sartomer 351), ethoxylated-20-trimethylolpropantriacrylate (ETA; Sartomer 415), divinyl adipate (DVA) and tetrakis(3-mercaptopropionate) (TT) the issue of biocompatibility is addressed, as recent in-vivo studies have shown no inflammatory round cells and good bony ingrowth has been observed. A new class of vinylester, thiols and acrylate-based monomers have shown to have similar photoreactivity and mechanical properties to methacrylates. Fur-thermore, non-toxic and low molecular polyvinylalcohol is produced as a degradation product. Special attention had been given to the choice of appropriate surfactant as the surfactant activity is one of the main factors affecting the emulsion stability. Produced materials were characterized using FTIR spectroscopy, scanning electron micros-copy, gas adsorptions porosimetry and mercury porosimetry. In collaboration with the Tech-nical University Vienna (prof. Robert Liska) and the Medical University of Vienna (ddr. Günter Russmüller) measurements regarding biodegradability will be performed. Promising materials has been printed by DL
Keywords:polyHIPE, thiol-ene click chemistry, biological cells, photopoylmerisation


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