Vpliv poroznosti nanovlaken iz polikaprolaktona na sproščanje in rast probiotika rodu Bacillus

Lukovnjak, Tadej (author), Kocbek, Petra (mentor), Zupančič, Špela (comentor)

Parodontalna bolezen predstavlja resen globalni zdravstveni problem. Trenutni načini zdravljenja so neučinkoviti in večkrat vodijo do ponovnih zagonov bolezni. Eden izmed novih potencialnih načinov zdravljenja je lokalna dostava probiotikov, ki izvirajo iz ustne mikrobiote zdravih prostovoljcev in sproščajo protimikrobne snovi. Namen magistrskega dela je bil izdelati in vrednotiti hidrofobna nanovlakna iz polikaprolaktona in polietilenoksida z vgrajenimi sporami bakterij seva 25.2.M iz rodu Bacillus. V magistrski nalogi smo z elektrostatskim sukanjem izdelali polimerna nanovlakna z vgrajenimi sporami (1,15 x 108 CFU/g). Z različnimi metodami smo vrednotili vpliv mešanice topil in procesa na preživetje spor, morfologijo nanovlaken, sproščanje spor iz nanovlaken ter kalitev spor in rast bakterij na trdnem gojišču. S pomočjo vrstične elektronske mikroskopije smo potrdili, da so bile spore uspešno vgrajene v polikaprolaktonska nanovlakna. S statistično analizo smo dokazali signifikantne razlike v premeru nanovlaken z različnim deležem polietilenoksida, medtem ko se debelina plasti nanovlaken med vzorci ni bistveno razlikovala. Ugotovili smo, da se je z izpostavitvijo spor mešanici topil zmanjšala koncentracija živih spor za eno logaritemsko enoto, medtem ko elektrostatsko sukanje ni bistveno vplivalo na njihovo preživetje. Sestava nanovlaken ni vplivala na število preživelih spor. Z različnim deležem polietilenoksida v nanovlaknih smo spreminjali njihovo poroznost po izpostavitvi vodnemu mediju. Dokazali smo, da poroznost vpliva na hitrost sproščanja spor iz nanovlaken, in sicer sproščanje hitreje poteka iz nanovlaken z večjim deležem polietilenoksida. Iz polikaprolaktonskih nanovlaken s 40 % polietilenoksida se je sprostilo približno 10-krat več spor kot iz polikaprolaktonskih nanovlaken brez dodatka polietilenoksida. S pomočjo optične mikroskopije smo ugotovili, da se čas, ki je potreben za kalitev spor in izraščanje probiotika iz nanovlaken, med različnimi vzorci razlikuje. Bakterije so se iz nanovlaken s 40 % polietilenoksida začele izraščati že po 8 h, iz nanovlaken s 5 % polietilenoksida pa šele po 14 h. Nanovlakna na osnovi polikaprolaktona z dodatkom polietilenoksida predstavljajo obetaven način za lokalno dostavo potencialnih probiotikov za zdravljenje parodontalne bolezni in predstavljajo alternativni pristop v boju proti bakterijski rezistenci.

• Language: Slovenian
• Keywords: bakterije, elektrostatsko sukanje, nanovlakna, parodontalna bolezen, polietilenoksid, polikaprolakton.
• Work type: Master's thesis/paper
• Organization: FFA - Faculty of Pharmacy
• Year: 2019
• PID: 20.500.12556/RUL-113323
• Publication date in RUL: 20.12.2019

Secondary language

• Language: English
• Title: Effect of polycaprolactone nanofiber porosity on release and growth of probiotic from genus Bacillus

Abstract

Periodontal disease is a serious global health problem. Current treatment strategies are ineffective and often result in the disease recurrence. One of the new potential treatments is the local delivery of probiotics, which originate from the oral microbiota of healthy volunteers and release antimicrobials. The aim of the master's thesis was to prepare and evaluate hydrophobic nanofibers of polycaprolactone and polyethylene oxide with incorporated spores of bacterial strain 25.2.M of the genus Bacillus. In the master's thesis, electrospinning was used to produce polymer nanofibers with incorporated spores (1.15 x 108 CFU/g). The influence of solvent mixture and process on the spore viability, nanofiber morphology, spore release from nanofibers and their germination were evaluated by various methods. Using scanning electron microscopy, we confirmed that the spores were successfully incorporated into polycaprolactone nanofibers. Statistical analysis revealed significant differences in the diameter of nanofibers, while the thickness of the nanofiber mats was not significantly different between the samples. We have shown that the exposure of spores to the solvent mixture, reduced the concentration of live spores by 1 log unit, while electrospinning did not significantly affect their viability. The composition of the nanofibers did not affect the spore viability. By altering the content of polyethylene oxide in the nanofibers, their porosity after exposure to the aqueous medium was adjusted. Porosity has been shown to affect the rate of spore release from nanofibers, thus the release occurs faster from nanofibers with higher content of polyethylene oxide. About 10 times higher amount of spores was released from polycaprolactone nanofibers with 40 % polyethylene oxide compared to polycaprolactone nanofibers without the addition of polyethylene oxide. Using optical microscopy, we showed that the time required for spore germination and outgrowth of probiotic from nanofibres varies between samples. The bacteria outgrowth from nanofibers with 40 % polyethylene oxide started already after 8 h, while it took 14 h for bacteria to grow from nanofibers with 5 % polyethylene oxide. Polycaprolactone based nanofibers with addition of polyethylene oxide represent a promising approach for local delivery of potential probiotics for the treatment of periodontal disease and represent an alternative way in the fight against bacterial resistance.

• Keywords: bacteria, electrospinning, nanofibers, periodontal disease, polycaprolactone, polyethylene oxide.