Prikaz prirejenega sproščanja učinkovin z alginatnimi mikrosferami v šolskem laboratoriju : diplomsko delo

Hrast, Špela (author), Boh Podgornik, Bojana (mentor)

V diplomskem delu sem izdelala osnovnošolskemu okolju primerna eksperimenta, ki v šolskem laboratoriju učencem prikažeta osnovne principe prirejenega sproščanja zdravil in možnosti ciljne dostave farmacevtskih učinkovin. V prvem, teoretičnem delu je predstavljen alginat, ki je zaradi zmožnosti tvorbe mikrosfer osnova obeh eksperimentov, njegove lastnosti, uporaba in umestitev v učni načrt za osnovne šole in gimnazije. V drugem delu je opisan izbrani, poenostavljeni in optimiziran postopek, primeren za prikaz prirejenega sproščanja in za prikaz principa dostavnega sistema s ciljano dostavo v šolskem laboratoriju. Eksperiment, s katerim lahko s pomočjo alginata prikažemo prirejeno sproščanje snovi v šolskem laboratoriju, je razdeljen na dva dela. Prvi del predstavlja izdelavo alginatnih mikrosfer z modelno snovjo, katere osnova je povzeta po avtorjih Friedli in Schlager (2005), drugi pa omogoča opazovanje sproščanja modelne snovi iz alginatnih mikrosfer. Zaradi cenovne dostopnosti, hitrega sproščanja iz alginatnih mikrosfer in obarvanosti, ki omogoča neposredno opazovanje sproščanja modelne snovi, sem za modelno snov izbrala prehransko barvilo. Celoten eksperiment ne vsebuje zahtevnih korakov; pripomočki in kemikalije, ki jih potrebujemo, so cenovno dosegljivi in varni za uporabo. Ker je prehransko barvilo v vodni raztopini kalcijevega klorida vidno takoj, za popolno sprostitev iz mikrosfer pa je potrebno več ur, je eksperiment primeren za prikaz prirejenega sproščanja, v katerem prehransko barvilo predstavlja model nizkomolekularne zdravilne učinkovine s postopnim sproščanjem. Tudi eksperiment, s katerim lahko s pomočjo alginata prikažemo dostavni sistem s ciljano dostavo v šolskem laboratoriju, sem razdelila na dva dela, in sicer na izdelavo hitozan-alginatnih mikrosfer z govejim serumskim albuminom (BSA) ter opazovanje sproščanja BSA iz hitozan-alginatnih mikrosfer. Za izdelavo hitozan-alginatnih mikrosfer sem izbrala in preizkusila tri različne postopke. Zaradi enostavne, časovno ustrezne izvedbe in kompaktnosti sintetiziranih mikrosfer se je kot najboljši izkazal postopek s povzetimi osnovnimi koraki po Meng idr. (2011). Pri opazovanju sproščanja BSA iz hitozan-alginatnih mikrosfer sem izbrala in preizkusila tri različne metode določanja sproščenega BSA: določanje absorpcije BSA s spektrofotometrom, semikvantitativno določanje vsebnosti BSA z biuretsko reakcijo in določanje svetlobne prepustnosti raztopine s šolskim spektrometrom SpektraTM. Kot najprimernejša metoda za prikaz dostavnega sistema s ciljano dostavo v šolskem laboratoriju se je izkazalo semikvantitativno določanje vsebnosti BSA z biuretsko reakcijo. Rezultati so namreč hitro vidni in določljivi. Prav tako osnovnošolski učenci že poznajo pomen in delovanje biuretske reakcije, zato lahko iz rezultatov sklepajo, da se je pri kisli pH-vrednosti iz mikrosfer sprostilo manj BSA kot pri pH-vrednosti 7. Tako lahko z uporabo biuretske reakcije nazorno prikažemo princip farmacevtskega dostavnega sistema s ciljano dostavo učinkovine v kolon, kjer BSA predstavlja zdravilo, čaša z 0,5% vodno raztopino klorovodikove kisline ponazarja okolje v želodcu, čaša s pufrom s pH-vrednostjo 7 pa okolje v tankem črevesju.

• Language: Slovenian
• Keywords: alginat, hitozan-alginatne mikrosfere, dostavni sistem
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: PEF - Faculty of Education
• Publisher: [Š. Svetiičič]
• Year: 2014
• Number of pages: 44 str.
• PID: 20.500.12556/RUL-69171
• UDC: 57.012.3:664.644.7(043.2)
• COBISS.SI-ID: 10243657
• Publication date in RUL: 10.07.2015

Secondary language

• Language: English
• Title: Alginate microspheres for demonstration of controlled release in a school laboratory

Abstract

In my thesis I have made two experiments suitable for primary school that demonstrate the basic principles of controlled drug release and the potential of targeted drug delivery system in a school laboratory. The first, theoretical part describes alginate, which is the base for both experiments due to its ability to form microspheres, its properties, application and placement in the curriculum for primary and high schools. The second part describes the selected, simplified and optimized method suitable for demonstration of controlled release and the principle of the targeted delivery system in a school laboratory. The experiment which demonstrates the controlled release of substances by using alginate in a school laboratory is divided into two parts. The first part represents the production of alginate microspheres with a model substance that is based on the authors Friedli and Schlager (2005), while the second part enables the observation of the release of the model substances from alginate microspheres. Due to its affordability, fast release from alginate microspheres and colouring, which allows direct observation of the release of a model substance, I chose food colouring as the model substance. The experiment does not include any complex steps; the laboratory equipment and the chemicals needed are affordable and safe to use. The experiment serves as a demonstration of controlled release, in which the food colouring is a model of low-molecular-weight drug with a controlled release, since it is visible in an aqueous solution of calcium chloride within a few minutes but takes hours to completely leach out. I also divided the second experiment, which demonstrates the targeted delivery system by using alginate in the school laboratory, into two parts. The first part represents the production of chitosan-alginate microspheres with bovine serum albumin (BSA) and the second part enables the observation of the release of BSA from chitosan-aliginate microspheres. I chose and tested three different procedures for the production of chitosan-alginate microspheres. The procedure based on Meng et. al. (2011) has proven to be the best due to the simple, time-appropriate synthesis and the compactness of the synthesized microspheres. In observing the BSA release from the chitosan-alginate microspheres I chose and tested three different methods for determining the released BSA: the determination of the BSA absorption with a spectrophotometer, the semi-quantitative BSA determination with a biuret reaction and the determination of the light transmittance of the solution with the school spectrometer SpektraTM. The most appropriate method to demonstrate the target delivery system in the school laboratory has proven to be the semi-quantitative BSA determination with biuret reaction. The results are quickly visible and identifiable. Besides, primary pupils already know the meaning and functioning of biuret reaction, so they can conclude from the results that the microspheres in the solution with acidic pH-value release less BSA than in the solution with pH-value 7. Therefore biuret reaction can be used for demonstration of drug delivery to colon, where BSA represents the drug, beaker with 0.5% aqueous solution of hydrochloric acid illustrates the environment in the stomach and the beaker with a buffer with pH-value 7 the environment in the small intestine.