Priprava poroznih biomaterialov

diplomsko delo univerzitetnega študijskega programa I. stopnje

Laura Gruškovnjak (Author), Maja Leitgeb (Mentor), Gregor Kravanja (Co-mentor), Mateja Primožič (Co-mentor)

Abstract

Tkivo v človeškem telesu se lahko zaradi različnih poškodb, nesreč ali bolezni poškoduje, zato se vsak dan opravi veliko število operacijskih posegov s katerimi se to tkivo popravi oziroma nadomesti. Do nedavnega je večina teh posegov obsegala presaditev tkiv ali celotnih organov, v zadnjem desetletju pa se vse več uporabljajo biološki nadomestki, imenovani biomateriali oziroma celična ogrodja. Njihova prednost je v tem, da so biorazgradljivi, torej se po dokončani funkciji v telesu sami razgradijo in ni potrebno ponovno posegati v pacientovo telo. Prav tako pa se za celična ogrodja zahteva visoka poroznost in povezanost por s katerimi se spodbudi rast novih tkiv. Pri regeneraciji kostnega tkiva se največkrat kot biomateriali uporabljajo polisaharidi, ki imajo vrsto koristnih lastnosti predvsem biokompatibilnost in bioaktivnost. V okviru diplomske naloge smo s postopkom sušenja z zamrzovanjem pripravili različne biomateriale. Kot polisaharide smo uporabili natrijev alginat, hitozan, guar, ksantan, dekstran in karboksimetil hitozan. Uspešno sintetiziranim biomaterialom smo določili poroznost in proučili nabrekanje v fosfatnem pufru. S pomočjo elektronskega vrstičnega mikroskopa smo posneli pore v notranjosti materiala in s pomočjo FTIR analize dokazali vsebnost vseh komponent v končnem celičnem ogrodju. Kontaktne kote biomaterialov smo izračunali s pomočjo računalniškega programa Image J. S tem smo dobili podatek o hidrofobnosti oziroma hidrofilnosti biomateriala. Prav tako smo biomaterialom dodali naravno komponento, ki se nahaja v človeških kosteh, hidroksiapatit, in preučili njegov vpliv na lastnosti prvotnih celičnih ogrodij. Ker pa je zrela kost sestavljena iz dveh tkiv, mehkejše in trdnejše, smo s pomočjo superkritičnega ogljikovega dioksida pripravili biomaterial iz sintetičnega biorazgradljivega poliestra polikaprolaktona. To ogrodje je zaradi drugačne priprave trdnejše, a manj porozno. Skupaj z mehkejšim ogrodjem pripravljenim z liofilizacijo, ki je posledično zaradi namakanja v kalcijevem kloridu bolj porozno, tvorita večslojni biomaterial za aplikacije kostnega inženiringa.

Keywords

polisaharidi;polikaprolakton;porozni biomateriali;hidroksiapatit;liofilizacija;superkritični ogljikov dioksid;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2020
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher:	[l. Gruškovnjak]
UDC:	577.124.5(043.2)
COBISS:	34225155
Views:	549
Downloads:	81
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Preparation of porous biomaterials
Secondary abstract:	The tissue in the human body can be damaged because of different injuries, accidents, or diseases. Therefore, a lot of surgical procedures are performed every day. Thus, the tissue is improved or substituted. Until recently, most of the procedures included tissue transplantations or organ transplantations. In the recent decade, however, the use of biological substitutes called biomaterials or cellular scaffolds has been increasing. Their advantage is that they are biodegradable. After their function is completed, therefore, they degrade automatically and there is no need to intervene in the patient’s body again. High porosity and the porosity of pores are demanded for cellular scaffolds. Thus, the growth of new tissues is induced. Polysaccharides are used as biomaterials on most occasions in the regeneration of bone tissue. They have several useful characteristics, above all biocompatibility and bioactivity. Within the framework of the bachelor’s thesis, we prepared different biomaterials by the procedure of freeze-drying. We used sodium alginate, chitosan, guar, xanthan, dextran, and carboxymethyl chitosan as polysaccharides. We studied the porosity and swelling of the successfully evolved biomaterials in phosphate buffer. Using an electron scanning microscope, we recorded pores in the interior of the material and proved the content of all components in the final cellular scaffold using the FTIR analysis. We calculated the contact angles of biomaterials using the Image J computer program. Thus, we got the information on hydrophobicity and hydrophilicity of the biomaterial. We also added a natural component found in human bones, hydroxyapatite, to biomaterials and studied its influence on the characteristics of the original cellular scaffolds. Because a mature bone is constructed of the two tissues, softer and harder, however, we prepared biomaterial from synthetic biodegradable polyester polycaprolactone using supercritical carbon dioxide. This scaffold was harder but less porous because of different preparation. Together with the softer framework prepared with lyophilization which, consequently, is more porous because of soaking in calcium chloride they form a multilayer biomaterial for the applications of bone engineering.
Secondary keywords:	polysaccharides;polycaprolactone;porous biomaterials;hydroxyapatite;freeze-drying;supercritical carbon dioxide;
Type (COBISS):	Bachelor thesis/paper
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	X, 47 str.
ID:	11836247