In situ sinteza metalnim ionima dopiranog hidroksiapatita u polimernoj matrici kitozana

master's thesis

• Title (english): In situ synthesis of metal ions substituted hydroxyapatite in chitosan matrix
• Author: Helena Paun
• Mentor: Hrvoje Ivanković (mentor)
• Committee member: Hrvoje Ivanković (predsjednik povjerenstva)
• Committee member: Juraj Šipušić (član povjerenstva)
• Committee member: Anamarija Rogina (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2018-09-27, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering; Chemical Engineering in Material Development

Abstract

Inženjerstvo koštanog tkiva je interdisciplinarno područje usmjereno na razvoj biomaterijala za izradu trodimenzijskih okosnica koje oponašaju prirodno koštano tkivo. Okosnica se ugradnjom na oštećeno područje kosti sjedinjuje s okolnim tkivom, potiče njegovu regeneraciju, te se istovremeno razgrađuje i osigurava mjesto za rast novog koštanog tkiva. Okosnice koje oponašaju prirodno koštano tkivo izrađene su iz organsko-anorganskih kompozitnih materijala po uzoru na prirodno koštano tkivo koje se sastoji od istih. Organsku fazu čini izvanstanična matrica većinski građena od kolagena, koju zbog strukturalne sličnosti najčešće oponašaju prirodni polimeri. Hidroksiapatit je glavna anorganska komponenta koštanog tkiva, zbog čega se koristi kao anorganska faza u izradi okosnica. Biološki hidroksiapatit u svojoj strukturi sadrži elemente u tragovima koji su neophodni za metabolizam kosti i organizam. Mnoga istraživanja usmjerena su na dopiranje hidroksiapatita cinkovim ionom koji ima antibakterijska svojstava te pozitivno utječe na aktivnost osteoblasta i regeneraciju tkiva. U ovom radu su pripremljeni uzorci cinkovim ionom dopiranog hidroksiapatita (0, 1, 5 i 10 mol% cinka) metodom precipitacije. Sinteza je provedena korištenjem prekursora kalcijevih iona iz biogenog i sintetskog izvora. Sastav uzoraka, prije i nakon toplinske obrade, utvrđen je rendgenskom difrakcijskom analizom i infracrvenom spektroskopijom s Fourierovim transformacijama. Sintezom iz biogenog izvora nastaje dvofazni sustav hidroksiapatita i oktakalcij fosfata, dok iz sintetskog izvora jednofazni sustav hidroksiapatita. Nakon toplinske obrade uzoraka nastaje dvofazni sustav α i ß-trikalcijev fosfata. Ugradnja cinkova iona u strukturu oktakalcij fosfata pentahidrata i ß-trikalcijev fosfata praćena je promjenama parametara elementarne rešetke. Zbog neznatnih promjena parametara elementarne rešetke hidroksiapatita, pretpostavlja se da je došlo do adsorpcije cinkova iona na površinu kristala. Dodatno, provedena je in situ sinteza cinkom dopiranog hidroksiapatita (sintetski prekursor kalcijevih iona) u polimernoj matrici kitozana. Karakterizacija dobivenih poroznih struktura provedena je infracrvenom spektroskopijom s Fourierovim transformacijama i pretražnim elektronskim mikroskopom.

Abstract (english)

Bone tissue engineering is an interdisciplinary field focused on the development of biomaterials as three-dimensional scaffolds which mimic natural bone tissue. After implantation at injured site it integrates with the surrounding tissue, promotes bone regeneration, degrades and provides space for new bone tissue. The imitation of natural bone tissue is obtained by using biomaterials based on organic/inorganic materials. The organic phase is an extracellular matrix mostly composed of collagen. Due to its similarity to the extracellular matrix structure, the organic phase is often imitated by natural polymers. Hydroxyapatite is the major inorganic component of bone tissue and is often used in biomedical areas. Biological apatite contains trace elements in its structure which are essential for bone and body metabolism. Many studies have been focused on doping hydroxypatite structure with zinc ion, which is interesting because of antibacterial properties and positive effect on osteoblastic and tissue regeneration activity. In this study zinc doped hydroxyapatite (0, 1, 5 and 10 mol% zinc) was prepared by using precursors of calcium ions from biogenic and synthetic source. The composition of the samples was determined by X-ray diffraction analysis and infrared spectroscopy with Fourier transforms. From biogenic source was obtained two-phase system of hydroxyapatite and octacalcium phosphate pentahydrate, while from synthetic source one-phase system of hydrpxyapatite. After heat treatment it was obtained two-phase system of α and β-tricalcium phosphate. Decrease of cell parameters of octacalcium phosphate pentahydrate and β-tricalcium phosphate confirmed doped structures with zinc ions. However, it can be assumed that hydroxyapatite is not zinc doped and that zinc ions are adsorbed on crystal surface as cell parameter did not decrease. Additionally, in situ synthesis of zinc doped hydroxyapatite (from synthetic source) within chitosan matrix was obtained. Characterization of porous structures was determined by infrared spectroscopy with Fourier transforms and scanning electron microscopy.

• Keywords: hidroksiapatit; cink; kitozan; in situ
• Keywords (english): hydroxyapatite; zinc; chitosan; in situ
• Language: croatian
• URN:NBN: urn:nbn:hr:149:869122
• 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: Open access
• Created on: 2020-10-29 12:48:38