Title Metode ugradnje lijeka u polimerne mikročestice Title (english) Drug incorporation into polymeric microparticles Author Lucija Vlahović Mentor Anamarija Rogina (mentor)Committee member Anamarija Rogina (predsjednik povjerenstva)Committee member Hrvoje Ivanković (član povjerenstva)Committee member Leonard Bauer (član povjerenstva)Granter University of Zagreb Defense date and country 2023-09-12, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract Kitozan je jedini prirodni polimer polikationske prirode kojeg svojstva poput biokompatibilnosti, biorazgradljivosti i netoksičnosti čine idealnim za upotrebu u poljoprivredi, prehrambenoj i kozmetičkoj industriji, pročišćavanju otpadnih voda, tkivnom inženjerstvu te kao sustav za dostavu lijekova. Ovisno o primjeni, moguće je pripremiti materijale na temelju kitozana u obliku emulzija, filmova te mikro- i nano-čestica koje su se pokazale kao idealni dostavljači lijekova. Kako bi se postigla željena kinetika otpuštanja lijeka, a time i uspješno liječenje, potrebno je pripremiti mikro- i nanočestice kontrolirane raspodjele veličina, morfologije i strukture. Neke od metoda koje se koriste za pripremu kitozanskih mikročestica su elektroštrcanje, sušenje raspršivanjem, dobivanje iz emulzije i precipitacija. U ovom radu, proces elektroštrcanja je odabran za pripravu mikročestica. Pripremljene su kompozitne mikročestice na temelju kompleksa kitozana i bakrovih(II) iona koje kao punilo sadrže hidroksiapatit (CHT-Cu/HAp), te je istražen utjecaj dodatka hidroksiapatita na svojstva mikročestica i efikasnost ugradnje antitumorskog lijeka (doksorubicin, DOX). Suhe mikročestice analizirane su primjenom infracrvene spektroskopije s Fourierovom transformacijom prigušene totalne refleksije (ATR-FTIR) i rendgenskom difrakcijskom analizom (XRD) te rezultati ukazuju na prisutnost interakcija između polimerne matrice i punila. Veličina i oblik mikrosfera istraženi su invertnim svjetlosnim mikroskopom. Uočena je sferičnost pripremljenih mikročestica, dok su najmanje mikročestice s najužom raspodjelom dobivene za sustav s 5 mas.% HAp-a (CHT-Cu/HAp5). Dodatakom većeg udjela hidroksiapatita (10 mas.%) dobivene su veće mikročestice s širom raspodjelom veličina zbog nestabilnsti procesa elektroštrcanja. Stupanj bubrenja CHT-Cu/HAp mikročestica raste smanjenjem pH vrijednosti inkubacijskog medija i povećanjem udjela hidroksiapatita. Fluorescentna spektrometrija i gravimetrijska metoda korištene pri određivanju ugradnje DOX-a u pripremljene CHT-Cu/HAp mikročestice dale su neočekivane rezultate te su potrebna daljnja istraživanja kako bi se procjenila efikasnost ugradnje lijeka.
Abstract (english) Chitosan is the only natural polycationic polymer whose properties such as biocompatibility, biodegradability and non-toxicity make it ideal for use in agriculture, food and cosmetics industry, wastewater treatment, tissue and bone engineering and as a drug delivery system. Depending on the application, it is possible to prepare chitosan-based materials in the form of emulsions, films, and micro- and nanoparticles, which have proven to be ideal drug carriers. In order to achieve the desired drug release kinetics, and thus successful tumor treatment, it is necessary to prepare micro- and nanoparticles with a controlled size distribution, morphology and structure. Some of the methods used to prepare chitosan microparticles are electrospraying, spray drying, emulsion and precipitation methods. In this work, the electrospraying process was used for the preparation of microparticles. Composite microparticles based on chitosan‒copper(II) ions complex and hydroxyapatite (CHT-Cu/HAp) were prepared, while the influence of the addition of hydroxyapatite on the properties and drug loading efficiency of the antitumor drug (doxorubicin, DOX) was investigated. Dry microspheres were analyzed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray diffraction analysis (XRD), and the results indicated the presence of interactions between the polymer matrix and the filler. The size and shape of the microspheres were determined using an inverted light microscope. The sphericity of the prepared microparticles was observed, while the smallest microparticles with the narrowest size distribution were obtained for the system with 5 wt.% HAp (CHT-Cu/HAp5). At a higher content of hydroxyapatite (10 wt.%), larger microparticles with a wider size distribution were obtained due to the instability of the electrospraying process. The swelling degree of CHT-Cu/HAp microparticles increased at lower pH value of the incubation medium and at higher content of hydroxyapatite. Fluorescence spectrometry and the gravimetric method used to analyze the drug loading into the prepared CHT-Cu/HAp microparticles indicated unexpected results; therefore, further investigation is needed to assess the effectiveness of DOX.
Keywords
elektroštrcanje
kitozan
antitumorski lijek
fluorescencija
Keywords (english)
electrospray
chitosan
antitumor drug
fluorescence
Language croatian URN:NBN urn:nbn:hr:149:841506 Project Number: UIP-2020-02-6201 Study programme Title: Materials Science and Engineering - Undergraduate study Type of resource Text File origin Born digital Access conditions Open access Terms of use Created on 2023-09-14 10:16:57
