Priprava kompozitnih mikrosfera

master's thesis

• Title (english): Preparation of composite microspheres
• Author: Petra Ćurković
• Mentor: Anamarija Rogina (mentor)
• Committee member: Anamarija Rogina (predsjednik povjerenstva)
• Committee member: Marica Ivanković (član povjerenstva)
• Committee member: Hrvoje Ivanković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2020-09-14, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Basic Technical Sciences

Abstract

Cilj ovog rada je priprava kompozitnih mikrosfera na temelju kitozana i hidroksiapatita kao nosioca i dostavljača antitumorskog lijeka. Kod kitozana je nužno naglasiti svojstvo pH osjetljivosti koje bi omogućilo otpuštanje lijeka u neposrednoj blizini tumora. Međutim, kitozan može otpuštati lijek i prije dolaska na ciljano mjesto, stoga su kompozitni materijali pogodni za kontrolirano otpuštanje i dostavu lijeka. U ovome radu kompozitne mikrosfere su proizvedene metodom elektroštrcanja. Kompozitne mikrosfere pripravljene pri različitim udjelima hidroksiapatita (5 – 15%) s ciljem povećanja efikasnosti buduće inkapsulacije lijeka. Stabilnost mikrosfera postignuta je reakcijama kompleksiranja prijelaznih metala (bakra, odnosno, cinka) s makromolekula kitozana uslijed velikog afiniteta metalnih iona prema aminskim skupinama kitozana. Oblik, veličina i mikrostruktura mikrosfera istraženi su optičkim i pretražnim elektronskim mikroskopom, dok je sastav mikrosfera identificiran rendgenskom difrakcijskom analizom. Potvrđeno je da tijekom sinteze kompleksa kitozana i metalnih iona, odnosno, kompozita s metalnim ionima nisu nastali novi anorganski spojevi. Mikroskopska analiza ukazala je na visoko poroznu mikrostrukturu kompozitnih mikrosfera pripravljenih s cinkovim (II) ionima. Preliminarni test citotoksičnosti pokazao je da dodatak hidroksiapatita ne utječe na toksičnost uzoraka. Kompozitni materijali s bakrovim (II) ionima pri svim ispitivanim koncentracijama pokazali su određenu citotoksičnost koja je izraženija pri većoj koncentraciji bakrovih (II) iona. Nasuprot tome, kompozitni materijali s cinkovim (II) ionima nisu toksični za ispitivanu staničnu liniju.

Abstract (english)

The aim of this work was to prepare composite microspheres based on chitosan and hydroxyapatite as potential carriers for targeted antitumor drug delivery. It is important to highlight the pH sensitivity of chitosan, which allows trgeted drug release around tumor site. However, chitosan can release a drug before reaching the targeted site, hence, chitosan-based composite materials could be more suitable in order to increase stability of potential drug carrier. In this work, composite microspheres were synthesized via electrospraying process. The composites microspheres were prepared with different ratio of hydroxyapatite in chitosan solution (5 – 15%) in order to improve the efficiency of the future drug encapsulation. The stability of composite microspheres was achieved through chelation of transition metal ions (copper and zinc) by chitosan macromolecules due to the high affinity of metal ions towards chitosan amino groups. The shape, size and microstructure of composite microspheres were analyzed by optical microscopy and SEM analysis, while the materials composition was identified by XRD analysis. The presence of new crystalline phases within chitosan complexes and composites with metal ions was not observed. The microscopic analysis has indicated highly porous structure of composite microspheres prepared by zinc (II) ions. The preliminary cytotoxicity assay indicated that hydroxyapatite do not influence on materials toxicity. The composites with different concentration of copper (II) ions showed cytotoxic effect, which was more evident for the materials with higher copper (II) ions concentration. On the contrary, composites with zinc (II) ions were nontoxic for cultured cell line.

• Keywords: kitozan; hidroksiapatit; cink; bakar; elektroštrcanje; mikrosfere; tkivno inženjerstvo
• Keywords (english): chitosan; hydroxyapatite; zinc; copper; electrospraying; microspheres; tissue engineering
• Language: croatian
• URN:NBN: urn:nbn:hr:149:167255
• Project: Number: IP-2014-09-3752; Title: Razvoj biokompatibilnih materijala na temelju hidroksiapatita za primjene u inženjerstvu koštanog tkiva; Title: Development of Biocompatible Hydroxyapatite Based Materials for Bone Tissue Engineering Applications; Acronym: HaTEA; Leader: Hrvoje Ivanković; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: Materials Science and Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2022-03-01 18:23:33