Porous copolymers of vinylesters and thiols as scaffolds for biological cells

Porozni polimerni materiali so vedno bolj uporabni za nanos bioloških celic in uporabo v tkivnem inženirstvu. Zato smo v magistrski nalogi pripravili porozne polimerne nosilce s pomočjo polimerizacije emulzije z visokim deležem notranje faze (HIP emulzije). Za pripravo smo izbrali nizko citotoksična monomera DVA in TT in jih ustrezno polimerizirali po principu stopenjske tiol-en foto polimerizacije. Pri pripravi HIP emulzije smo spreminjali različne parametre (količino surfaktantov, HLB vrednost surfaktantov, temperaturo vodne faze, temperaturo emulzije, razmerje monomerov) in s tem pridobili različne morfološke strukture vzorcev. Pri preučevanju vpliva dveh HLB vrednosti surfaktantov (2,31 in 3,29) in količine surfaktantov (15 vol. %, 20 vol. % in 25 vol.%), smo ugotovili, da količina surfaktanta pri posamezni HLB vrednosti vpliva na poliHIPE morfologijo in na velikost primarnih por. Pri HLB vrednosti 2,31 se s povečevanjem količine surfaktantov izboljšuje poliHIPE morfologija in nastajajo večje primarne pore. Pri HLB vrednosti 3,29 pa s povečevanjem količine surfaktantov porušimo poliHIPE morfologijo in zmanjšamo primarne pore. S spremembo temperature vodne faze na 40 °C prav tako vplivamo na morfologijo polimernega nosilca, in sicer pri večji HLB vrednosti (3,29) dobimo poliHIPE morfologijo, pri manjši HLB vrednosti (2,31) pa se izoblikuje bikontinuirna struktura. S spreminjanjem temperature emulzije nismo dosegli poliHIPE morfologije, vsi vzorci imajo bikontinuirno strukturo. Pri spreminjanju razmerja funkcionalnih skupin monomerov smo ugotovili, da primerno poliHIPE morfologijo pridobimo pri vzorcu MG7, kjer je razmerje funkcionalnih skupin monomerov 1:1. Preverili smo tudi biorazgradljivost polimernih materialov MG7 in MG8 v različnih koncentracijah NaOHaq (10-3 M, 10-4 M in 10-5 M ). Ugotovili smo, da razgradljivost pripravljenih vzorcev pada z nižanjem koncentracije NaOHaq. V 10-3 M NaOHaq se namreč razgradi 10 % vzorca, v 10-4 M NaOHaq se razgradi 6 % in v 10-5 M NaOHaq le še 3% vzorca. Opravili smo tudi karakterizacijo pripravljenih poliHIPE materialov. S FTIR spektroskopijo smo potrdili kemijsko sestavo poli(DVA-ko-TT) nosilca, s pomočjo adsorpcije/desorpcije dušika po BET metodi smo izmerili specifične površine. Izvedli smo tudi elementno analizo vzorcev, in ugotovili, da eksperimentalne vrednosti masnih deležev elementov ne odstopajo od teoretičnih vrednosti. Izmerili pa smo tudi mehanske lastnosti izbranih polimernih materialov.Porous polymer materials are increasingly being used as scaffolds for biological cells and tissue engineering. Therefore, in master\u27s degree we prepared porous polymer scaffolds by high internal phase emulsion (HIPE) templating. For the preparation of PolyHIPEs we have chosen a low cytotoxic monomer DVA and TT and thiol-ene step growth photo polymerization. In the preparation of the HIP emulsions, we modified various parameters (amount of surfactants, HLB values of the surfactants, temperature of the aqueous phase, temperature of the emulsion, ratio of monomers) and with this we gained different morphology of materials. In examining the impact of the two HLB values of surfactants (2,31 and 3,29) and the amount of surfactants (15 vol. %, 20 vol. % and 25 vol. %), we found that, the amount of surfactant in the individual HLB value have impact on polyHIPE morphology and the size of the primary pores. At HLB value of 2,31, with increasing the amount of surfactants improved poliHIPE morphology and generated larger primary pores. At HLB value of 3.29, by increasing amount of surfactants, polyHIPE morphology is destroyed and primary pores were reduced. With the change of the aqueous phase temperature at 40 °C we also influenced the polymer morphology. At higher HLB value (3,29) we got polyHIPE morphology, but with the lower HLB value (2,31) we got formation of bicontinuous structure. By varying the temperature of the emulsion we did not achieve polyHIPE morphology, all the samples have bicontinuous structure. When changing the ratio of functional groups of monomers, we determined that appropriate poliHIPE morphology are acquired for a sample of MG7, which has the ratio of the functional groups of the monomers of 1:1. We checked also the biodegradability of polymer materials MG7 and MG8 in different concentrations of NaOHaq (10-3 M, 10-4 M in 10-5 M ). We found that the degradability of prepared samples decreases with lowering the concentration of the NaOHaq. In 10-3 M NaOHaq has degraded 10 % of the sample, in 10-4 M NaOHaq has degraded 6% of the sample, and in 10-5 M NaOHaq only 3% of the sample. We\u27ve also done the characterization of prepared poliHIPE materials. With FTIR spectroscopy, we confirmed the chemical structure of the poly(DVA-co-TT) scaffolds. With adsorption desorption expreriments, using BET method, we measured the specific surface area. We also did the elementary analysis of the samples, and found that the experimental value of the mass proportions of elements do not distinct from the theoretical values. We have also measured the mechanical properties of selected polymeric materials