oleuropein

doktorska disertacija

Jasna Tompa (Author), Olivera Šauperl (Mentor), Julija Volmajer Valh (Co-mentor)

Abstract

Namen doktorske disertacije v osnovi izhaja iz postavljenega problema, da obstoječe protimikrobne obdelave celuloznih materialov, zaradi stalnih in prekomerno uporabljenih protimikrobnih spojin, vodijo do odpornosti mikroorganizmov na njihovo delovanje. Izmed naštetega še posebej izstopa obdelava tekstilnih substratov za razvoj produktov, namenjenih medicini in higieni. Trend razvoja inovativnih produktov je zato na omenjenem področju vse bolj usmerjen v protimikrobne obdelave površin celuloznih materialov, ki temeljijo izključno na rabi naravnih, ne-toksičnih in biološko razgradljivih učinkovin. V ta namen se pogosto uporablja hitozan, derivat hitina, ki izkazuje odlične lastnosti, kot so dobra adhezivnost, biološka razgradljivost in protimikrobna učinkovitost. Žal pa obdelave celuloznih materialov s hitozanom niso zmeraj idealno dobre v smislu ponovljivosti obdelave in zato ponovljive redukcije patogenih mikroorganizmov. Iz tega razloga je smiselno v obdelavo s hitozanom vključiti še katero izmed naravno protimikrobno delujočih spojin, na primer eugenol in oleuropein. Obe omenjeni učinkovini izkazujeta odlične biološke in farmakološke lastnosti, ki pa v kombinaciji s hitozanom in kasnejšim prenosom na izbran tekstilni substrat iz celuloze, še nimata vidnejše vloge. V doktorski disertaciji smo tako hitozan uporabili kot izhodno protimikrobno sredstvo za pripravo novih formulacij v kombinaciji z naravnima učinkovinama (eugenol, oleuropein). Namen vključitve omenjenih učinkovin v sistem s hitozanom predstavlja nadgradnjo in izboljšanje funkcionalnosti hitozana z antioksidativnimi, fizikalno-kemijskimi in biološkimi lastnostmi. To lahko dosežemo na različne načine, med drugim z metodo kemične in encimske funkcionalizacije, ki sta bili uporabljeni v fazi razvoja novih formulacij doktorske disertacije. Graft kopolimeri pridobljeni po omenjenih metodah so bili z vidika uspešnosti izvedene sinteze ovrednoteni z različnimi analiznimi metodami, in sicer spektroskopijo (ATR FT-IR, NMR, UV-VIS), potenciometrično titracijo, simultano termično analizo in z metodami za vrednotenje antioksidativne učinkovitosti (F-C, DPPH•, Redukcija Fe3+). Nadalje je raziskava potekala v smeri prenosa novo nastalih formulacij na izbran celulozni substrat. Zaradi dobrih površinskih aktivnosti, v smislu protimikrobne obdelave, je v ta namen bila izbrana viskoza kot primeren izhodni material za razvoj novih medicinskih in sanitetnih materialov. Za nanos posameznih obdelovalnih formulacij na površino viskoze je bil uporabljen impregnacijsko-sušilni postopek. Po opravljeni površinski funkcionalizaciji so bili vzorci viskoze okarakterizirani z ATR FT-IR spektroskopijo, metodo C.I Acid Orange VII, vrstično elektronsko mikroskopijo (SEM), mikrobiološkim testiranjem in kinetiko sproščanja. Na podlagi dobljenih rezultatov smo v celoti potrdili zastavljeno hipotezo in dognali, da je protimikrobna in antioksidativna funkcionalizacija viskoze obdelane z novo nastalimi formulacija odvisna od vrste učinkovine in uporabljene metode pridobitve graft kopolimera. V tem pogledu, sta se učinkovina eugenol in metoda kemične funkcionalizacije hitozana glede na učinkovino oleuropein in encimsko funkcionalizacijo hitozana, izkazali kot učinkovitejši.

Keywords

hitozan;celuloza;formulacija hitozan/eugenol;formulacija hitozan/oleuropein;graft kopolimerizacija;protimikrobnost;antioksidativnost;doktorske disertacije;

Data

Language:	Slovenian
Year of publishing:	2019
Typology:	2.08 - Doctoral Dissertation
Organization:	UM FS - Faculty of Mechanical Engineering
Publisher:	[J. Tompa]
UDC:	677.017:577.3(043.3)
COBISS:	22673942
Views:	782
Downloads:	92
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	FUNCTIONALIZATION OF CELLULOSE BY USING OF GRAFT COPOLYMER CHITOSAN/EUGENOL AND CHITOSAN/OLEUROPEIN
Secondary abstract:	The purpose of the doctoral dissertation basically arises from the established problem that the existing antimicrobial treatment of cellulosic materials, due to permanent and excessively used antimicrobial compounds, leads to the resistance of microorganisms. From that point, functionalization of textile substrates for the development of products intendent for medicine and hygiene is particularly exiting. The trend of the development of innovative products is, therefore increasingly directed towards antimicrobial treatment of surfaces of cellulosic materials based exclusively on the use of natural, non-toxic and biodegradable substances. For this purpose, chitosan, a derivative of chitin, which exhibits excellent properties, such as good adhesiveness, biodegradability and antimicrobial efficiency, is often used. Unfortunately, functionalization of cellulosic materials with chitosan is not always ideal in terms of reproducibility and, therefore, the reproducible reduction of pathogenic microorganisms. For this reason, one of the natural antimicrobial-acting compounds, e.g. eugenol and oleuropein, may be involved in treatment with chitosan. Both of these substances exhibit excellent biological and pharmacological properties, although these compounds have no visible role in combination with chitosan and subsequent application onto selected textile cellulose substrate. Within doctoral dissertation, chitosan was used as an antimicrobial agent to prepare new treatment formulations in combination with natural substances (eugenol, oleuropein). The purpose of incorporating these substances into the chitosan system is to upgrade and to improve chitosan functionality in regard to its antioxidant, physical-chemical and biological properties, respectively. This can be achieved in various ways, inter alia by the method of chemical and enzyme functionalization, which were used in the example of development of new functionalization formulations. Graft co-polymers obtained according to the above methods were evaluated from the point of view of the synthesis which was evaluated by various analytical methods, i.e. spectroscopy (ATR FT-IR, NMR, UV-VIS), potentiometric titration, simultaneous thermal analysis, and methods to evaluate antioxidant efficacy (FC, DPPH*, Fe3+ reduction). Furthermore, the study was carried out in the direction of application of the newly formed formulations to the selected cellulose substrate from viscose. Due to good surface activity, in terms of antimicrobial treatment, viscose was selected for this purpose as a suitable starting material for the development of new medical and hygiene materials. An impregnation-drying process was used to apply individual functionalization formulations onto the surface of viscose. After surface functionalization, the viscose samples were characterized by using ATR FT-IR spectroscopy, the C.I Acid Orange VII method, scanning electron microscopy (SEM), microbiological testing, and release kinetics, respectively. On the basis of the obtained results, the hypothesis was fully confirmed and it is concluded that the antimicrobial and antioxidant functionalization of viscose functionalized with newly formed formulations depending on the nature of the active compound and the method of the graft co-polymer preparation. In this respect, the eugenol and the chemical functionalization of chitosan in comparison to the oleuropein and the enzymatic functionalization of chitosan have proven to be more effective.
Secondary keywords:	chitosan;eugenol;oleuropein;cellulose;formulation of chitosan/eugenol;formulation of chitosan/oleuropein;graft co-polymerization;antimicrobial;antioxidative;
Type (COBISS):	Doctoral dissertation
Thesis comment:	Univ. v Mariboru, Fak. za strojništvo
Pages:	IX, 169 str.
ID:	11119560