The role of chitosan in tissue regeneration

Inženjerstvo tkiva je obećavajuća alternativa konvencionalnim metodama u medicini. U sklopu tog interdisciplinarnog polja, nastoje se naći biomaterijali kompatibilni s tkivom kojeg će zamijeniti i popraviti. Kitozan je često korišten materijal povoljnih svojstava koji se lako oblikuje u različite oblike ili modificira proteinima kao što je fibronektin, sekvencama poput RGD ili umreživanjem s drugim polimerima. Cilj ovog rada bio je dati kratki pregled svojstava kitozana, njegove primjene i uloge u inženjerstvu tkiva. U ovom radu pripremljene su porozne strukture na temelju kitozana visoke (HC) i srednje (MC) molekulske mase metodama liofilizacije (FD) i toplinski induciranog faznog razdvajanja uz geliranje i ekstrakciju (FG). Uzorci su karakterizirani pretražnim elektronskim mikroskopom te im je određen stupanj bubrenja testiranjem u vodenom mediju 24 sata pri temperaturi od 37 °C. Liofilizirani uzorci pokazali su visoko poroznu strukturu s međusobno povezanim porama duž cijelog volumena uzorka. Dobiveni su slojevi s različitim stupnjem homogenosti strukture. Površina membrana pripremljenih toplinski induciranim faznim razdvajanjem uz geliranje i ekstrakciju prekrivena je tankim filmom. Svi uzorci pokazali su znatnu moć bubrenja, a strukture pripremljene FD metodom su bile superiorne u odnosu na one pripremljene FG metodom. Provođenjem ANOVA statističke analize utvrđena je značajna razlika među uzorcima unutar podskupine I i II za obje molekulske mase kod prve metode, dok se kod druge razlika primjećuje između uzoraka različitih molekulskih masa.Tissue engineering is a promising alternative to conventional methods in medicine. Within this interdisciplinary field, the goal is to find biomaterials compatible with the tissue targeting to replace and heal. Chitosan is a frequently used material with favorable properties, and it is easily transformed into various shapes or modified by proteins such as fibronectin, sequences such as RGD or cross-linking with other polymers. The goal of this work was to give a short review on chitosan's properties, its application and role in tissue engineering. Chitosan porous structures of high (HC) and medium (MC) molecular weight were prepared using freeze drying (FD) and freeze gelation (FG) methods. Samples were characterized by scanning electron microscopy, while swelling test was done in aqueous media for 24 hours at 37 °C. Freeze dried sponges were highly porous with interconnected pores throughout the whole volume of the sample. The lyophilized samples were additionally cut into two sections based on their structure – I (homogenous), II (non-homogenous). The membranes prepared by freeze gelation showed the existence of thin film on their surface, even though they seemed porous based on visual examination. All samples demonstrated good swelling degree, while the structures obtained by FD method were superior comparing to FG ones. ANOVA statistical analysis indicated that there was a significant difference between the samples within sections I and II of both molecular weights for the first method, while in the second, a difference between samples of various molecular weights has been noted