Vpliv različnih nanodelcev TiO2 na aktivnost acetilholinesteraze : magistrsko delo

Jan, Zala (avtor), Drobne, Damjana (mentor), Jereb, Gregor (komentor)

Uvod: V zadnjih desetletjih proizvodnja nanomaterialov in nanodelcev globalno močno narašča, prav tako tudi njihova uporaba v številnih izdelkih. Za namene ugotavljana interakcij med različnimi nanodelci in biološkimi sistemi so na voljo različni testi. V magistrskem delu je uporabljen encimski test, katerega namen je ovrednotiti biološko reaktivnost različnih nanodelcev s testom inhibicije in adsorpcije acetilholinesteraze. Podatek o biološki aktivnosti je ključen pri vrednotenju njihove varne uporabe. Namen: Namen magistrskega dela je s spektrofotometrično Ellmanovo metodo oceniti stopnjo adsorpcije suspenzije različnih delcev TiO2 na encim acetilholinesterazo in inhibicijo encimske aktivnosti. Namen je tudi prikazati, kako koncentracija in lastnosti delcev vplivajo na aktivnost encima in preveriti odvisnost med adsorpcijo in inhibicijo encima. Metode dela: Uporabljena je bila modificirana Ellmanovo metoda, prilagojena za delo na mikrotitrskih ploščah. Izmerjen je bil vpliv dvanajstih različnih delcev TiO2 na inhibicijo in adsorpcijo acetilholinesteraze. Nastanek rumenoobarvanega kompleksa, ki se tvori ob reakciji med uporabljenimi nanodelci, Ellmanovim reagentom, encimom ter dodanim substratom acetiltioholinkloridom je bil beležen pri valovni dolžini 405 nm. Eserin je bil uporabljen kot pozitivna kontrola. Rezultati: Acetilholinesterazo so najbolj inhibirali in adsorbirali delci TiO2 velikosti med 5 in 100 nm, manj pa delci z velikostjo med 100 in 500 nm. Različna kristalna struktura delcev v naši študiji ni vplivala na aktivnost encima. Pri višjih koncentracijah delcev je bil vpliv na aktivnost encima večji, predvsem pri delcih, ki so povzročili več kot 10% vpliv na aktivnost encima. Vpliv na inhibicijo je bil pri analiziranih delcih večji od vpliva na adsorpcijo. Razprava in zaključek: Metoda, opisana v magistrskem delu, je lahko uporabljena za nadaljnje raziskovanje interakcij med encimi in ND.

• Jezik: Slovenski jezik
• Ključne besede: TiO2, acetilholinesteraza, inhibicija, adsorpcija, nanodelci
• Vrsta gradiva: Magistrsko delo/naloga
• Organizacija: ZF - Zdravstvena fakulteta
• Leto izida: 2019
• PID: 20.500.12556/RUL-109633
• COBISS.SI-ID: 5676395
• Datum objave v RUL: 06.09.2019

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: The impact of different TiO2 nanoparticles on the activity of acetylcholinesterase : master thesis

Izvleček

Introduction: Over the last decades, the production of nanomaterials and nanoparticles has been rapidly growing on the global scale. Different tests are available for the purposes of determining interactions between different nanoparticles and biological systems. In the master’s thesis, the enzyme test is used which aims to evaluate the biological reactivity of various nanoparticles with the test of inhibition and adsorption of acetylcholinesterase test. The data on biological activity is crucial in evaluating their safe use and in the development of new products containing nanomaterials. Purpose: The purpose of this master's thesis is to evaluate the rate of adsorption of the TiO2 particle suspension on the acetylcholinesterase enzyme and the inhibition of enzymatic activity using the spectrophotometric Ellman method. The purpose is also to show how the concentration and properties of the particles affect the enzyme activity and to compare the relation between enzyme adsorption and inhibition. Methods: A modified Ellman method, adapted to work with microtiter plates, was used. The effect of twelve different TiO2 particles on the inhibition and adsorption of acetylcholinesterase was measured. The reaction between the nanoparticles which were used, the Ellman’s reagent, the enzyme and the added acetylthiocholine chloride substrate results in the formation of a yellow-colored complex, which was recorded at a wavelength of 405 nm. Eserine was used as a positive control. Results: TiO2 particles with sizes between 5 and 100 nm showed the highest rate of inhibition and adsorption of acetylcholinesterase, whereas the particles with sizes between 100 and 500 nm showed a lower rate. The different crystal structure of the particles in our study did not affect the enzyme activity. At higher particle concentrations, the effect on enzyme activity was greater, especially with particles which had more than 10 % impact on enzyme activity. In the particles used, the effect on inhibition was greater than the effect on adsorption. Discussion and conclusion: The method described in the master's thesis can be used to further investigate the interactions between enzymes and nanoparticles.

• Ključne besede: TiO2, acetylcholinesterase, inhibition, adsorption, nanoparticles