Antibakterijski porozni nosači na temelju kitozana

undergraduate thesis

• Title (english): Antibacterial porous chitosan-based scaffolds
• Author: Tea Leskovar
• Mentor: Anamarija Rogina (mentor)
• Committee member: Anamarija Rogina (predsjednik povjerenstva)
• Committee member: Iva Bazina (član povjerenstva)
• Committee member: Marica Ivanković (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2024-09-20, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Zbog svojih izvrsnih svojstava poput biokompatibilnosti, biorazgradljivosti, antibakterijskog te antimikrobnog djelovanja, kitozan (CHT) pokazuje široku primjenu u prehrambenoj, poljoprivrednoj i farmaceutskoj industriji te medicini. Cilj ovoga rada bio je istražiti antibakterijska svojstva pripremljenih poroznih nosača na temelju kitozana s bakrovim(II) ionima uz dodatak hidroksiapatita (CHT-Cu/HAp) na gram-pozitivnu (Staphylococcus aureus) i gram-negativnu bakteriju (Klebsiella pneumoniae). CHT-Cu/HAp hidrogelovi različitih masenih udjela hidroksiapatita (0, 5, 10 i 20 mas.%) dobiveni su neutralizacijom s
1,25 mol dm^-3 otopinom natrijeva hidroksida, a suhi porozni nosači (aerogelovi) procesom liofilizacije. Suhi porozni CHT-Cu/HAp uzorci istraženi su infracrvenom spektroskopijom s Fourierovom transformacijom (FTIR), a dobiveni rezultati ukazuju na postojanje interakcije između polimerne matrice i punila. Stupanj bubrenja (SB), istražen u fosfatom puferiranoj otopini soli (PBS) pri fiziološkim uvjetima (pH 7,4; 37 °C) tijekom 24 h, ukazuje na izostanak značajnih statističkih razlika između uzoraka različitog kemijskog sastava, odnosno stupanj bubrenja za sve uzorke iznosi između 17–21. Antibakterijska svojstva pripremljenih poroznih CHT-Cu/HAp nosača istražena su primjenom disk-difuzijske metode na dvije bakterijske kulture: Staphylococcus aureus (gram-pozitivna bakterija) i Klebsiella pneumoniae
(gram-negativna bakterija). Rezultati pokazuju da uzorci s dodatkom hidroksiapatita
(CHT-Cu/HAp5, CHT-Cu/HAp10 i CHT-Cu/HAp20), prethodno nabubreni u PBS-u tijekom 3 i 24 h, posjeduju antibakterijsko djelovanje na gram-pozitivnu bakteriju. Kod svih CHT-Cu/HAp uzoraka je uočen izostanak antibakterijskog djelovanja za gram-negativnu bakteriju. Također, svi suhi uzorci nisu pokazali antibakterijsko djelovanje na obje bakterije. Uspješno pripremljeni porozni nosači na temelju kitozana, bakrovih(II) iona i hidroksiapatita pokazali su dobra antibakterijska svojstva protiv gram-pozitivnih bakterija, uz potencijalnu primjenu u biomedicinskom području.

Abstract (english)

Due to its excellent properties such as biocompatibility, biodegradability, antibacterial, and antimicrobial effects, chitosan (CHT) demonstrates wide application in the food, agricultural, and pharmaceutical industries, as well as in medicine. The aim of this study was to investigate the antibacterial properties of the prepared porous
chitosan-copper (II)/hydroxyapatite-based (CHT-Cu/HAp) scaffolds on Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Klebsiella pneumoniae).
CHT-Cu/HAp hydrogels with varying amount of hydroxyapatite (0, 5, 10, and 20 wt.%) were obtained by neutralisation with 1.25 mol dm^-3 sodium hydroxide solution, while dry porous carriers (aerogels) were obtained through lyophilization. The dry porous CHT-Cu/HAp samples were analysed by Fourier-transform infrared spectroscopy (FTIR), and the results indicate the presence of interactions between the polymer matrix and the filler. The swelling degree (SB) was investigated in phosphate-buffered saline solution (PBS) under physiological conditions (pH 7.4; 37 °C) for 24 hours, and there were no significant statistical differences between samples with different chemical composition, with the swelling degree for all samples ranging between 17–21. The antibacterial properties of the prepared porous CHT-Cu/HAp scaffolds were examined using the disk diffusion method on two bacterial cultures: Staphylococcus aureus (Gram-positive bacteria) and Klebsiella pneumoniae
(Gram-negative bacteria). The results show that the samples with the addition of hydroxyapatite (CHT-Cu/HAp5, CHT-Cu/HAp10 i CHT-Cu/HAp20), pre-swollen in PBS for
3 and 24 h, exhibited antibacterial activity against the Gram-positive bacteria.
All CHT-Cu/HAp samples show no antibacterial activity against the Gram-negative bacteria. Additionally, all dry samples showed a lack of antibacterial activity against both Gram-positive and Gram-negative bacteria. The successfully prepared porous scaffolds based on chitosan, copper (II) ions, and hydroxyapatite demonstrated good antibacterial properties against Gram-positive bacteria, with potential applications in biomedical field.

• Keywords: kitozan; hidroksiapatit; bakrovi(II) ioni; aerogel; antibakterijsko djelovanje
• Keywords (english): chitosan; hydroxyapatite; copper (II) ions; aerogel; antibacterial activity
• Language: croatian
• URN:NBN: urn:nbn:hr:149:573384
• Project: Number: UIP-2020-02-6201; Title: Pametni sustavi za dostavu lijeka pri liječenju tumora kosti; Title: Smart drug delivery systems in bone tumour treatment; Acronym: SmartCar; Leader: Anamarija Rogina; Jurisdiction: Croatia; Funder: Hrvatska zaklada za znanost; Funding stream: Installation Research Projects
• Study programme: Title: Materials Science and Engineering - Undergraduate study; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Embargoed access; Embargo expiration date: 2025-06-01
• Created on: 2024-11-17 11:43:37