Mehanizmi nastajanja biokompozitnih materijala u sustavima kalcijeva karbonata i biološki značajnih molekula

doctoral thesis

• Title (english): Formation mechanisms of biocomposites based on calcium carbonates and biologically relevant molecules
• Author: Lara Štajner
• Mentor: Damir Kralj (mentor)
• Committee member: Vladislav Tomišić (predsjednik povjerenstva)
• Committee member: Jasminka Kontrec (član povjerenstva)
• Committee member: Daniel Mark Lyons (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Chemistry); Zagreb
• Defense date and country: 2018-06-12, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Chemistry
• Universal decimal classification (UDC): 54 - Chemistry. Crystallography. Mineralogy

Abstract

Biomineralizacija je proces nastajanja slabo topljivih soli u živim organizmima, uz prisustvo biološki značajnih makromolekula. Nastajanje biokompozita specifičnih fizičko-kemijskih svojstava predložak je za biomimetičku sintezu novih funkcionalnih materijala. Kalcijev karbonat odabran je kao model biomineralizacije zbog složenosti sustava i makromolekula koje u tom procesu sudjeluju.
Sustavno je istraženo djelovanje malih organskih molekula (aminokiseline, dipeptidi i derivati salicilne kiseline) i ionotropnosti (gelatori male molekulske mase) na nukleaciju te rast kalcita. Utjecaj na nukleaciju ispitan je indirektno eksperimentima spontanog taloženja, dok je utjecaj na rast istražen dodatkom kristalnog sjemena kalcita. Navedenim istraživanjima dobiven je uvid u mehanizam i doseg interakcija malih organskih molekula i površine kalcita određivanjem Langmuirovih konstanti adsorpcije.
Dokazano je da polarne aminokiseline utječu na nukleaciju i rast, a ne samo kisele aminokiseline. Dipeptidi imaju veći utjecaj zbog sinergijskog djelovanja dviju funkcionalnih skupina aminokiselina. Najveći utjecaj uočen je dodatkom salicilnih derivata, koji bi se mogli koristiti kao nosači lijekova.

Abstract (english)

Biomineralization is the formation of sparingly soluble salts in living organisms, strongly influenced by biologically active macromolecules. Formation of biocomposites, with specific physico-chemical properties, is a suitable model for the biomimetic approach of new materials synthesis. Calcium carbonate was selected as a biomineralization model due to the complexity of the system and the macromolecules involved in this process.
Systematic research was carried out on small organic molecules' influence (amino acids, dipeptides and derivatives of salicylic acid) and ionotropy (low molecular weight galators) on nucleation and calcite growth. Their influence on nucleation was investigated by experiments on spontaneous precipitation, while seeded precipitation was used for observing their influence on growth. Insight into the interactions between small organic molecules and calcite surfaces was gained from Langmuir adsorption constants.
Polar amino acids also influenced nucleation and growth, apart from acidic amino acids. Higher influence of dipeptides was observed due to the sinergistic effect of two amino acid functional groups. The strongest influence was noted for salicylic derivatives, which could be used as a drug delivery system.

• Keywords: kalcijev karbonat; aminokiseline; dipeptidi; salicilna kiselina; nosač lijeka; biomimetika; biomineralizacija
• Keywords (english): calcium carbonate; amino acids; dipeptides; salicilic acid; drug delivery; biomimetics; biomineralization
• Language: croatian
• URN:NBN: urn:nbn:hr:217:934363
• Study programme: Title: Doctoral study in chemistry; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija (doktor/doktorica znanosti, područje prirodnih znanosti, polje kemija)
• Type of resource: Text
• Extent: 162 str. ; 30 cm
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-07-10 12:14:22