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Crosslinking of thermosensitive functionalized copolymers by blue light
Křivánková, Nikola ; Michlovská, Lenka (oponent) ; Vojtová, Lucy (vedoucí práce)
The aim of this thesis was to prepare a hydrogel with a hybrid network of only one type of biodegradable copolymer. The new degradable hydrogel, containing both physical interactions (arising at physiological temperature of 37 °C) and chemical bonds initiated by blue light could be used as a resorbable wound dressing or as an injectable carrier with a gradual and well controlled drug release. Thermosensitive PLGA–PEG–PLGA copolymer synthesized by living ring-opening polymerization was subsequently functionalized with itaconic anhydride to form ITA/PLGA–PEG–PLGA/ITA light-sensitive and temperature-sensitive macromonomer. At 37 °C, the copolymer forms a micellar network due to hydrophobic interactions. Itaconic acid double bonds, which are attached to the ends of the copolymer chain, allow photochemical crosslinking of micelles with a view to increase the hydrolytic stability of novel hydrogel. The synthesized copolymers were characterized by GPC and 1H NMR methods. The formation of a physical network at physiological temperature was confirmed by rheological analysis. The physically crosslinked ITA/PLGA–PEG–PLGA/ITA hydrogel was then irradiated with blue light (430 – 490 nm) in the presence of a water soluble biocompatible photoinitiator LiTPO and chemically characterized by ATR-FTIR. The resulting hydrogel was transparent, flexible, absorbed up to 1176 % water, and was stable for 20 days in saline at 37 °C. The ITA/PLGA–PEG–PLGA/ITA hydrogel with hybrid network was also prepared in the presence of a crosslinker PEGDA, that significantly reduced the time required for crosslinking the hydrogel, but further analyses are needed to more fully understand the principles of the novel hydrogel types.
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Crosslinking of thermosensitive functionalized copolymers by blue light
Křivánková, Nikola ; Michlovská, Lenka (oponent) ; Vojtová, Lucy (vedoucí práce)
The aim of this thesis was to prepare a hydrogel with a hybrid network of only one type of biodegradable copolymer. The new degradable hydrogel, containing both physical interactions (arising at physiological temperature of 37 °C) and chemical bonds initiated by blue light could be used as a resorbable wound dressing or as an injectable carrier with a gradual and well controlled drug release. Thermosensitive PLGA–PEG–PLGA copolymer synthesized by living ring-opening polymerization was subsequently functionalized with itaconic anhydride to form ITA/PLGA–PEG–PLGA/ITA light-sensitive and temperature-sensitive macromonomer. At 37 °C, the copolymer forms a micellar network due to hydrophobic interactions. Itaconic acid double bonds, which are attached to the ends of the copolymer chain, allow photochemical crosslinking of micelles with a view to increase the hydrolytic stability of novel hydrogel. The synthesized copolymers were characterized by GPC and 1H NMR methods. The formation of a physical network at physiological temperature was confirmed by rheological analysis. The physically crosslinked ITA/PLGA–PEG–PLGA/ITA hydrogel was then irradiated with blue light (430 – 490 nm) in the presence of a water soluble biocompatible photoinitiator LiTPO and chemically characterized by ATR-FTIR. The resulting hydrogel was transparent, flexible, absorbed up to 1176 % water, and was stable for 20 days in saline at 37 °C. The ITA/PLGA–PEG–PLGA/ITA hydrogel with hybrid network was also prepared in the presence of a crosslinker PEGDA, that significantly reduced the time required for crosslinking the hydrogel, but further analyses are needed to more fully understand the principles of the novel hydrogel types.
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