Biomaterijali u inženjerstvu tkiva temeljeni na kitozanu-literaturni pregled

undergraduate thesis

• Title (english): Chitosan based biomaterials for tissue engineering-review
• Author: Nediljko Beus
• Mentor: Hrvoje Ivanković (mentor)
• Committee member: Hrvoje Ivanković (predsjednik povjerenstva)
• Committee member: Sebastijan Orlić (član povjerenstva)
• Committee member: Vanja Kosar (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2015-09-18, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Basic Technical Sciences; Materials

Abstract

Kitozan je linaearan, semikristalični polisaharid sastavljen od jedinica N-acetil D-glukozamina i D-glukozamina. Može se lako dobiti djelomičnom deacetilacijom prirodnog polimera hitina. Zahvaljujući amino skupinama D-glukozamina, kitozan je moguće protonirati, čime postaje polikation, što je jedan od uzroka jedinstvenim svojstvima kitozana kao biopolimera, kao što su topljivost u vodi, antibakterijska svojstva, biorazgradnja bez toksičnih otpada i biokompatibilnost. Kitozan je jedini poznati pozitivno nabijeni polisaharid. Zahvaljujući svojoj strukturi i kemijskom sastavu, kitozan može stvarati 3-D predloške, u obliku hidorgelova i spužvi, koji mogu zamjeniti oštećeno tkivo ili organ, te omogućavaju spajanje sa okolnim stanicama tkiva i proliferaciju. Razvijena su tri tipa hidrogela reverzibilnim i ireverzibilnim geliranjem. Kitozan može biti fizički vezan, koordiniran sa metalnim ionima ili nepovratno/kemijski povezan sa hidrogelom. Spužve od kitozana se koriste kao materijal za lječenje rana, jer mogu upiti izlučevine rana, te tako pomažu zacjeljenju. Ove spužve se proizvode liofilizacijom, jednostavnim učikovitim procesom smrzavanja otopine kitozana nakon čega slijedi isparavanje otapala pri sniženom tlaku. U slučajevima kad nije pogodno koristiti 3-D predložak korise se 2-D predlošci: tanki filmovi i porozne membrane od nanovlakana. Razvijene su dvije metode dizajniranja višeslojnih filmova kitozana: Langmuir-Blodget, u kojoj se čvrsta potpora uranja u vodu prekrivenu slojem polimera, i depozicija sloj po sloj, temeljena na izmjenjenoj adsorpciji nabijenog materijala ili nosioca funkcionalnih grupa u vodenom mediju. Za proizvodnju nanovlakana iz kitozana koristi se metoda „elektrospininga“, u kojoj se otopina polimera injektira na ploču kroz sloj električnog polja visoke voltaže, pod čijim se utjecajem formiraju vlakna.

Abstract (english)

Chitosan is linear, semi-crystalline polysaccharide composed of N-acetyl D-glucosamine and D-glucosamine units. It can be easily derived from partial deacetylation of natural polymer chitin. Thanks to the amino groups of D-glucosamine, chitosan can be protonated and turned into polycation, which is one of sources of unique properties of chitosan as biopolymer, like aqueous solubility, antibacterial properties, biodegradability with non-toxic residues and biocompatibility. Chitosan is only known positively charged polysaccharide. Thanks to the strucure and chemical components, chitosan can form 3-D scaffolds, in form of hydrogels and sponges, which can replace damadged tissue or organ, and allows interaction with surrounding tissue cells and proliferation. Three types of hydrogels have been developed, presenting either reversilbe or irreversible gelation. Chitosan can be physically associated, coordinated with metal ions or irreversibly/ chemically cross- linked into hydrogels. Chitosan sponges are used as wound healing materials, as they can soak up the wound exudated, while helping the tissue regeneration. These sponges are mainly obtained by lyophilization, a simple efficient process consisting in freezing a solution of chitosan followed by sublimation of solvent under reduced pressure. In some cases when it is not suitable to use 3-D scaffolds, 2-D scaffolds are used: thin films and porous nanofiber membranes. Two methods to design chitosan thin films are developed: Langmuir-Blodgett, in which a solid support is immersed in aqueous phase covered in polymer monolayer, and the layer-by-layer deposition technique, based on the lternated adsorption of materials bearing charged or functional groups in aquous medium. For chitosan nanofiber production elecrospinning method is used, in which polymer solution in injected onto a plate through high-voltage electric field, which formes fibers.

• Keywords: kitozan; hitin; biomaterijali; hidrogel; spužve; tanki slojevi; nanovlakna
• Keywords (english): chitosan; chitin; biomaterials; hydrogel; sponges; thin films; nanofibers
• Language: croatian
• URN:NBN: urn:nbn:hr:149:630008
• 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: Open access
• Created on: 2016-11-29 18:17:07