Title Razvoj novih fosfolipidnih terapijskih sustava za topikalnu antimikrobnu terapiju
Title (english) Development of novel phospholipid drug delivery systems for topical antimicrobial therapy
Author Zora Rukavina
Mentor Željka Vanić (mentor)
Committee member Anita Hafner (predsjednik povjerenstva)
Committee member Maja Šegvić Klarić (član povjerenstva)
Committee member Biserka Cetina-Čižmek (član povjerenstva)
Granter University of Zagreb Faculty of Pharmacy and Biochemistry (Department of pharmaceutical technology) Zagreb
Defense date and country 2019-11-20, Croatia
Scientific / art field, discipline and subdiscipline BIOMEDICINE AND HEALTHCARE Pharmacy Pharmacy
Universal decimal classification (UDC ) 615 - Pharmacology. Therapeutics. Toxicology
Abstract Učinkovita topikalna terapija infekcija kože te prevencija stvaranja biofilmova i razvoja rezistencije
mikroorganizama od velikog su medicinskog značaja. Cilj ovog rada bio je razviti biorazgradljiv,
djelotvoran i siguran terapijski sustav za topikalnu antimikrobnu terapiju, zasnovan na fosfolipidnim
vezikulama (liposomima) uklopljenima u kitozansku podlogu. U tu svrhu pripravljeno je i evaluirano
nekoliko tipova liposoma s uklopljenim azitromicinom (AZT) različitog naboja na površini i
čvrstoće/elastičnosti fosfolipidnih dvoslojeva: konvencionalni liposomi (CL), deformabilni liposomi (DL),
propilenglikol liposomi (PGL) i kationski liposomi (CATL). Čvrstoća/elastičnost fosfolipidnih dvoslojeva
AZT-liposoma utjecala je na fizičku stabilnost, profil oslobađanja AZT-a i lokalizaciju antibiotika u koži.
Najsporije oslobađanje AZT-a, te odlaganje na površini kože, postignuto je CATL-om, karakteriziranim
čvrstim dvoslojevima. Elastični liposomi (DL i PGL) pokazali su brže oslobađanje te nakupljanje AZT-a u
unutrašnjosti kože. Svi AZT-liposomi pokazali su antibakterijski učinak na MRSA kliničke izolate, pri
čemu su minimalne biofilm inhibitorne koncentracije bile i do 32 puta manje od onih utvrđenih za
AZT-otopinu. Najjači anti-MRSA učinak imali su CATL, potom slijede DL, PGL i CL. Svi AZT-liposomi
bili su biokompatibilni s keratinocitima i fibroblastima, čak i pri značajno većim koncentracijama AZT-a od
pripadajućih minimalnih inhibitornih koncentracija i minimalnih biofilm inhibitornih koncentracija.
Uklapanjem AZT-liposoma u kitozansku podlogu produljeno je oslobađanje AZT-a i postignuta prikladna
viskoznost za topikalnu primjenu na kožu. Anti-MRSA učinak svih formulacija liposomi-u-podlozi bio je
znatno veći od onog postignutog s kontrolom. Teksturna analiza ispitivanih formulacija liposomi-u-podlozi
pokazala je prikladnu čvrstoću, kohezivnost i adhezivnost formulacija, posebice PGL-u-podlozi, a koje su
direktno povezane s njihovom primjenom i zadržavanjem na koži. Uzimajući u obzir rezultate svih
provedenih ispitivanja, formulacija CATL-u-podlozi bila bi prikladna za liječenje MRSA-om uzrokovanih
infekcija kod kojih je potrebna lokalizacija antibiotika u površinskim slojevima kože, dok bi formulacija
PGL-u-podlozi omogućila bolju dostavu antibiotika u dublje slojeve kože. Međutim, potrebno je provesti
in vivo animalna ispitivanja terapijske učinkovitosti kako bi se te pretpostavke i potvrdile.
Abstract (english) Effective topical therapy of complicated skin infections, prevention of biofilm formation and antimicrobial
resistance is of great medical importance. The aim of this research was to develop a biodegradable, efficient
and safe delivery system for topical antimicrobial therapy, based on the drug-loaded phospholipid vesicles
(liposomes) incorporated into the chitosan-based vehicle. For that purpose several types of
azithromycin-loaded (AZT) liposomes with different surface charges and rigidity/elasticity of
(phospho)lipid bilayers have been prepared and evaluated: conventional liposomes (CLs), deformable
liposomes (DLs), propylene glycol-embedding liposomes (PGLs) and cationic liposomes (CATLs). The
rigidity/elasticity of AZT-loaded liposomes influenced their physical stability, AZT release profile and its
localization inside the skin. The slowest release and deposition of AZT on the skin surface was achieved by
CATLs, characterized with rigid bilayers, whereas elastic liposomes (DLs and PGLs) demostrated faster
release and accumulation of the drug within the skin. All AZT-loaded liposomes showed antibacterial
activity against MRSA clinical isolates, with minimal biofilm inhibitory concentrations up to 32-fold lower
than those determined for the AZT-solution. The strongest anti-MRSA effect was demonstrated by CATLs,
followed by DLs, PGLs and CLs. All AZT-loaded liposomes were biocompatible with keratinocytes and
fibroblasts, even at AZT concentrations significantly higher than the corresponding minimal inhibitory
concentrations and minimal biofilm inhibitory concentrations. Incorporation of AZT-loaded liposomes into
the chitosan vehicle resulted in the prolonged AZT release and viscosity appropriate for skin application.
AZT-liposomes incorporated into chitosan vehicle, especially CATL-in-vehicle, demonstrated significantly
enhanced anti-MRSA effect, as compared to the chitosan vehicle embedding AZT-solution. Texture
analysis of AZT-liposomes incoroporated into chitosan vehicle showed a suitable hardness, cohesiveness
and adhesiveness, in particular PGL-in-vehicle, which are directly related to their skin application and
retention. Considering the results of all the experiments performed, CATL-in-vehicle would be suitable for
the treatment of MRSA-infections requiring localization of the antibiotic in the upper layers of the skin,
while PGL-in-vehicle facilitates delivery of AZT into deeper skin layers. However, further in vivo animal
studies are necessary to confirm those assumptions.
Keywords
deformabilni liposomi
propilenglikol liposomi
kationski liposomi
azitromicin
kitozan
topikalna primjena
koža
meticilin-rezistentni Staphylococcus aureus
MRSA
Keywords (english)
deformable liposomes
propylene glycol-embedding liposomes
cationic liposomes
azithromycin
chitosan
topical drug delivery
skin
methicillin-resistant Staphylococcus aureus
MRSA
Language croatian
URN:NBN urn:nbn:hr:163:358813
Promotion 2021
Study programme Title: Pharmacy and biochemistry Study programme type: university Study level: postgraduate Academic / professional title: doktor znanosti (doktor znanosti)
Type of resource Text
File origin Born digital
Access conditions Open access
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Created on 2021-05-24 12:39:35