Ugradnja flavonoida u mesoporozne magnetske nanočestice i utjecaj magnetskog polja na kinetiku njihovog otpuštanja

undergraduate thesis

• Title (english): Encapsulation of flavonoids into the mesoporous magnetic nanoparticles and the influence of the external magnetic fields on the kinetics of their release
• Author: Marina Punčec
• Mentor: Davor Dolar (mentor)
• Committee member: Davor Dolar (predsjednik povjerenstva)
• Committee member: Jelena Macan (član povjerenstva)
• Committee member: Suzana Šegota (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2018-09-20, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry; Physical Chemistry

Abstract

Preparacija mesoporoznih magnetitnih (Fe3O4) nanočestica postignuta je modificiranom solvotermalnom reakcijom amonijevog acetata, željezovog triklorid heksahidrata i polietilen glikola u etilen glikolu. Njihova fizikalno-kemijska, strukturna, magnetska i morfološka karakterizacija provedena je rendgenskom difrakcijom praha, pretražnom elektronskom mikroskopijom (SEM), elektroforetskim raspršenjem svjetlosti (ELS), Brunauer-Emmet-Teller (BET) analizom, supravodljivim kvantnim interferometrom (SQUID) i infracrvenom spektroskopijom (FTIR). Flavonoidi kvercetin, miricetin i miricitrin su ugrađeni u pripremljene mesoporozne magnetitne nanočestice. Istražen je utjecaj vanjskih magnetskih polja, permanentnog i oscilirajućeg, na kinetiku otpuštanja flavonoida. Pomoću generatora izmjenične struje spojenog na zavojnicu generirano je oscilirajuće magnetsko polje željenih frekvencija (0,1 Hz, 1,0 Hz i 10 Hz). Za izvor permanentnog magnetskog polja poslužio je magnet jakosti 0,19 T. Koncentracija otpuštenih flavonoida u zadanim vremenima pratila se ultraljubičastom-vidljivom (UV/VIS) spektroskopijom. Ustanovljeno je da nanočestice imaju pravilnu kristaliničnu strukturu s veličinom kristalita od 32 nm. S obzirom na specifičnu površinu od 16,69 m^2 g^-1, promjera pora 25,93 nm i volumena pora 0,106 cm^3 g^-1 sintetizirane nanočestice pripadaju skupini mesoporoznih nanočestica. Da bi se mogle primijeniti u oscilirajućem magnetskom polju, nanočestice magnetita moraju biti superparamagnetične, što je potvrđeno mjerenjem magnetizacije zasićenja. Pripremljene nanočestice pokazuju dobar model za ugradnju flavonoida, pri čemu se kvercetin najbolje ugrađuje od izabranih flavonoida. S obzirom na strukturu flavonoida to je u skladu s očekivanim. Miricetin, najhidrofobniji flavonoid od korištenih, te miricitrin s dodatnom ramnozom zbog steričkih faktora slabije se ugrađuju u nanočestice. Otpuštanje flavonoida iz magnetitnih nanočestica pod djelovanjem permanentnog i oscilirajućeg magnetskog polja je najizraženije pri frekvenciji osciliranja od 10 Hz.

Abstract (english)

Preparation of mesoporous magnetic nanoparticles was achieved through modified solvothermal reaction from iron(iii) chloride hexahydrate, ammonium acetate, polyethylene glycol and ethylene glycol that were all dissolved in ethylene glycol. Their physical-chemical, structural, magnetic and morphological characterization was performed by X-ray powder diffraction, scanning electron microscopy (SEM), electrophoretic light scattering (ELS), Brunauer-Emmet-Teller (BET) analysis, superconductive quantum interferometer (SQUID) and infrared spectroscopy (FTIR). Flavonoids quercetin, miricetin and miricitrin were incorporated into prepared mesoporous magnetite nanoparticles. We examined the influence of the external and oscillating external magnetic fields on the kinetics of the release of flavonoids. The oscillating magnetic field of the desired frequencies (0.1 Hz, 1.0 Hz and 10 Hz) was generated by the alternating current generator connected to the coil. For the source of the permanent magnetic field, a magnitude 0.19 T was used. The concentration of the released flavonoids at predetermined time was monitored by ultraviolet/visible (UV / VIS) spectroscopy. It has been found that nanoparticles have a proper crystalline structure with a crystal size of 32 nm. Given the specific surface area of 16.69 m^2 g^-1, pore diameter 25.93 nm and pore volume 0.106 cm^3 g^-1 synthesized nanoparticles belong to the group of mesoporous nanoparticles. To be applied in an oscillating magnetic field, nanoparticles of magnetite must be superparamagnetic, as confirmed by the measurement of saturation magnetization. The prepared nanoparticles exhibit a good model for incorporating flavonoids, whereby the quercetin is best fitted from the chosen flavonoids. Given the structure of flavonoids this is in line with the expected. Miricetin, the most hydrophobic flavonoid of the used, and miricitrine with additional rhamnose due to steric factors, are poorly incorporated into nanoparticles. Release of flavonoids from magnetite nanoparticles under the action of permanent and oscillating magnetic fields is most pronounced at the oscillation frequency of 10 Hz.

• Keywords: magnetitne nanočestice; flavonoidi; kvercetin; miricetin; miricitrin; mesoporoznost; superparamagnetičnost
• Keywords (english): magnetite nanoparticles; flavonoids; quercetin; myricetin; myricitrin; mesoporosity; superparamagnetism
• Language: croatian
• URN:NBN: urn:nbn:hr:149:021927
• Project: Number: IP-2016-06-8415; Title: Zaštitni mehanizmi i učinci flavonoida ugrađenih u nanonosače u modelnim membranama i neuronima; Acronym: NanoFlavNeuroProtect; Leader: Suzana Šegota; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Chemical Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-05-26 11:51:10