Razvoj nanovlaken iz polikaprolaktona z vgrajenimi probiotiki

Kastelic, Aljaž (author), Kocbek, Petra (mentor), Zupančič, Špela (co-mentor)

Parodontalna bolezen je vnetna bolezen, ki prizadene dlesni in lahko vodi v izgubo zob. Vnetne procese spremlja neravnovesje mikrobiote v obzobnih žepih, ki pa so težko dostopni za zdravljenje s tradicionalnimi dostavnimi sistemi. V zadnjem času se na področju lokalnega zdravljenja parodontalne bolezni spodbuja razvoj novih, naprednih dostavnih sistemov. Eden izmed takšnih dostavnih sistemov so nanovlakna, ki jih odlikuje velika specifična površina, bioadhezivnost in biokompatibilnost, če so ustrezno načrtovana. V nanovlakna lahko s procesom elektrostatskega sukanja vgradimo probiotike, ki po vnosu v parodontalne žepe v njih ponovno vzpostavijo mikrobiološko ravnovesje. Cilj magistrske naloge je bil razvoj nanovlaken s probiotiki na osnovi polikaprolaktona. Kot potencialni probiotik smo uporabili sev Bacillus sp. 25.2.M., ki sporulira, zato smo pri izdelavi vlaken uporabljali spore, ki so bolj odporne na agresivne dejavnike kot vegetativna oblika bakterij. Ugotavljali smo vpliv topil na preživetje probiotikov in najperspektivnejša topila s stališča preživetja spor, topnosti in sprejemljivosti za elektrostatsko sukanje polikaprolaktona uporabili za izdelavo začetnih formulacij nanovlaken. Medprocesno analizo nanovlaken smo izvajali z optično mikroskopijo, bolj natančno pa smo debelino in morfologijo nanovlaken ovrednotili s pomočjo vrstične elektronske mikroskopije. Proces izdelave nanovlaken z elektrostatskim sukanjem smo optimizirali tako, da smo spreminjali koncentracijo polimera, sestavo mešanice topil, prevodnost polimerne raztopine, pogoje elektrostatskega sukanja. Pripravili smo tudi vlakna z dodatkom hidrofilnega polimera (polietilenglikola ali polietilenoksida) ter jih optimizirali s spreminjanjem sestave zmesi obeh polimerov. V dve najobetavnejši formulaciji (nano)vlaken smo vgradili probiotike in ovrednotili njihovo preživetje v različnih stopnjah priprave (nano)vlaken. Določili smo tudi vsebnost probiotikov v (nano)vlaknih in njihov profil sproščanja. Ugotovili smo, da je metoda elektrostatskega sukanja primerna za vgrajevanje probiotikov v (nano)vlakna, saj je bila viabilnost probiotikov v nanovlaknih 3,88 log CFU/mgpolimera. Ugotovili smo, da probiotiki v nanovlaknih iz polikaprolaktona ne pridejo v stik z gojiščem, zato spore ne vzkalijo. Vključitev PEO v strukturo vlaken je povečala njihovo poroznost in omogočila sproščanje spor iz vlaken.

• Language: Slovenian
• Keywords: nanovlakna, elektrostatsko sukanje, polikaprolakton, probiotiki, spore
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2019
• PID: 20.500.12556/RUL-107357
• Publication date in RUL: 03.04.2019

Secondary language

• Language: English
• Title: Development of polycaprolactone nanofibers with incorporated probiotics

Abstract

Paradontosis is an inflammatory disease, which affects gums. It leads to loss of teeth. The process of inflammation is followed by unbalanced level of microbiota in periodontal pockets, which are very hard to reach with conventional drug delivery systems. Modern delivery systems have been developing for the purposes of local treatment of periodontal disease in the recent years. We introduce perspective delivery system, based on nanofibers with incorporated probiotics. The advantages of nanofibers are high specific surface area, bioadhesion and biocompatibility. It has been a promising method for recolonisation of periodontal pockets with probiotics. The aim of this master thesis was the developement of policaprolactone nanofibers with incorporated probiotics. We selected and produced a strain Bacillus sp. 25.2.M, which was able to sporulate. We used spores, which are more resistant to aggressive chemical agents than vegetative bacteria. We produced nanofibers with electrospinning process and used the most perspective solvents mixture according to viability, solubility and ability of electrospinning process. Diameters and morphology of nanofibers were analysed with optical microscopy and scanning electron microscopy. An optimization of the nanofibers was carried out to improve the electrospinning process. We were changing polymer concentration, mixture of solvents, conductivity of polymer solution and electrospinning parameters. Polyethylene glycol or polyethylene oxide were added to increase porosity of fibers. Finally we produced (nano)fibers based on the two most promising policaprolactone solution with incorporated probiotics. We evaluated the viability of probiotic spores in different stages of preparing (nano)fibers with incorporated probiotics. Based on the viability 3,88 log CFU/mgpolymer, we confirmed that electrospinning method was successful for production of (nano)fibers with probiotics. We can conclude that some additional optimization experiments should be done to improve the processibility of electrospinning process. Based on SEM photos and release profile we can conclude that spores in PCL nanofibers did not get in touch with medium, therefore spores did not change to vegetative bacteria. Incorporation of PEO into fibers structure increased porosity and enabled spores to release from fibers.

• Keywords: nanofibers, electrospinning, polycaprolactone, probiotics, spores