Vliv chitosanu na antibakteriální vlastnosti nanovláken
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Date
2023-10-12
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Tato bakalářská práce se zabývá vlivem chitosanu (CHIT) na antibakteriální vlastnosti směsných nanovláken. Teoretická část této práce poskytuje základní informace o chitosanu ale také o jeho antibakteriálních účincích a následném využití v různých oblastech. Také se zaměřuje na různé faktory, které ovlivňují výsledné vlastnosti chitosanu. Tato práce také zmiňuje základní informace o metodě elektrostatického zvlákňování. Uvádí také informace o klasifikaci bakterií na grampozitivní a gramnegativní. Chitosan je přírodní polysacharid se zajímavými vlastnostmi. Jednou z hlavních vlastností je přirozená antibakteriální aktivita způsobená přítomností primárních aminoskupin na jeho polymerním řetězci. Vzhledem k obtížné zpracovatelnosti elektrostatickým zvlákňováním v čisté podobě je výhodné chitosan mísit s vhodnými polymery. Tato práce se zabývá antibakteriálními vlastnostmi jeho směsi s hydrofobním polykaprolaktonem (PCL). Nanovlákna obsahující PCL a chitosan v různém poměru až do obsahu 30 % CHIT byla testována z hlediska inhibice bakteriálního růstu metodou Kolonie tvořící jednotku (CFU, Colony forming unit) po dvou hodinách expozice. Dále byl studován vliv složení nanovláken na bakteriální adhezi z hlediska počtu adherovaných bakterií v čase a jejich rozměru. Jako modelové bakterie byly použity grampozitivní kok Staphylococcus gallinarum a gramnegativní tyčinka Escherichia coli. Tato práce ze získaných dat přinesla poznatky o bakteriální adhezi na PCL/CHIT nanovláknech a o antibakteriálním účinku PCL/CHIT nanovláken. Směsná PCL/CHIT nanovlákna u bakteriálního kmene Staphylococcus gallinarum inhibovala růst již při podílu 5 % chitosanu o 3 řády. Při podílu 20 % chitosanu došlo k úplné inhibici S. gallinarum (o 5 řádů). U bakterie Escherichia coli k prokazatelné inhibici růstu nedošlo. Z hlediska bakteriální adheze u bakterie Staphylococcus gallinarum se snížil počet bakterií na nanovláknech při podílu 20 % chitosanu. Počet adherovaných bakterií se v čase neměnil. U bakterie E. coli narostl počet adherovaných bakterií až po 6 hodinách expozice, a to jen u vzorků s podílem 20 % a 30 % chitosanu. Velikost bakterií rostla se zvyšujícím se podílem chitosanu v nanovláknech. Byl prokázán významný vliv podílu chitosanu ve směsných PCL/CHIT nanovláknech na bakteriální odezvu.
This bachelor thesis deals with the influence of chitosan (CHIT) on the antibacterial properties of blended nanofibers. The theoretical part of this thesis provides basic information about chitosan but also about its antibacterial effects and its subsequent use in various fields. It also focuses on the various factors that influence the resulting properties of chitosan. This thesis also mentions basic information about the electrospinning method. It provides information of the classification of bacteria into Gram-positive and Gram-negative. Chitosan is natural polysaccharide with interesting properties. One of the main properties is the natural antibacterial activity caused by the presence of primary amino groups on its polymer chain. Due to the difficulty of processing by electrospinning in pure form, it is advantageous to blend chitosan with suitable polymers. This thesis focuses on the antibacterial properties of its blend with hydrophobic polycaprolactone (PCL). Nanofibers containing PCL and chitosan in various ratios up to 30 % CHIT were tested for inhibition of bacterial growth by the Colony Forming Unit (CFU) method after two hours of exposure. Furthermore, the influence of nanofiber composition on bacterial adhesion was studied in terms of the number of bacteria adhered over time and their size. The gram-positive coccus Staphylococcus gallinarum and the gram-negative rod Escherichia coli were used as model bacteria. Based on the obtained data, this thesis provided insights into bacterial adhesion on PCL/CHIT nanofibers and the antibacterial effect of PCL/CHIT nanofibers. The blended PCL/CHIT nanofibers inhibited the growth of a bacterial strain of Staphylococcus gallinarum at a chitosan content of 5 % by 3 orders of magnitude. At a 20 % chitosan content, S. gallinarum was completed inhibited (by 5 orders of magnitude). For Escherichia coli, no significant growth inhibition was observed. Regarding bacterial adhesion, the number of bacteria on the nanofibers decreased at 20 % chitosan content for Staphylococcus gallinarum. The number of adhered bacteria did not change over time. For E. coli, the number of adhered bacteria increased only after 6 hours of exposure and only for samples with 20 % and 30 % chitosan content. The size of bacteria increased with increasing chitosan content in the nanofibers. The chitosan content in blended PCL/CHIT nanofibers was shown to significantly influence bacterial response.
This bachelor thesis deals with the influence of chitosan (CHIT) on the antibacterial properties of blended nanofibers. The theoretical part of this thesis provides basic information about chitosan but also about its antibacterial effects and its subsequent use in various fields. It also focuses on the various factors that influence the resulting properties of chitosan. This thesis also mentions basic information about the electrospinning method. It provides information of the classification of bacteria into Gram-positive and Gram-negative. Chitosan is natural polysaccharide with interesting properties. One of the main properties is the natural antibacterial activity caused by the presence of primary amino groups on its polymer chain. Due to the difficulty of processing by electrospinning in pure form, it is advantageous to blend chitosan with suitable polymers. This thesis focuses on the antibacterial properties of its blend with hydrophobic polycaprolactone (PCL). Nanofibers containing PCL and chitosan in various ratios up to 30 % CHIT were tested for inhibition of bacterial growth by the Colony Forming Unit (CFU) method after two hours of exposure. Furthermore, the influence of nanofiber composition on bacterial adhesion was studied in terms of the number of bacteria adhered over time and their size. The gram-positive coccus Staphylococcus gallinarum and the gram-negative rod Escherichia coli were used as model bacteria. Based on the obtained data, this thesis provided insights into bacterial adhesion on PCL/CHIT nanofibers and the antibacterial effect of PCL/CHIT nanofibers. The blended PCL/CHIT nanofibers inhibited the growth of a bacterial strain of Staphylococcus gallinarum at a chitosan content of 5 % by 3 orders of magnitude. At a 20 % chitosan content, S. gallinarum was completed inhibited (by 5 orders of magnitude). For Escherichia coli, no significant growth inhibition was observed. Regarding bacterial adhesion, the number of bacteria on the nanofibers decreased at 20 % chitosan content for Staphylococcus gallinarum. The number of adhered bacteria did not change over time. For E. coli, the number of adhered bacteria increased only after 6 hours of exposure and only for samples with 20 % and 30 % chitosan content. The size of bacteria increased with increasing chitosan content in the nanofibers. The chitosan content in blended PCL/CHIT nanofibers was shown to significantly influence bacterial response.
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Subject(s)
Nanovlákna, chitosan, polykaprolakton, antibakteriální účinek, bakteriální adheze