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  • 學位論文

幾丁聚醣於不同有機酸中對光動力殺菌之影響

Effect of chitosan solubilized in various organic acids on photodynamic inactivation

指導教授 : 蔡翠敏

摘要


光動力殺菌對於微生物的感染治療是一種尚未普遍用於臨床而仍在開發中的技術。光動力殺菌已被證實對於革蘭氏陽性菌、革蘭氏陰性菌、真菌和其抗藥性菌株具有良好的殺菌效益。許多文獻也證實對微生物重複進行光動力治療尚未有抗性問題的產生,且除非需要用到相當高濃度的光感物質及高劑量光照,否則對人體正常細胞並不造成明顯傷害。幾丁聚醣為一帶正電的聚合物,利用幾丁聚醣搭配光動力殺菌,不僅可提升光動力殺菌效益且可進一步降低光感物質濃度,來減少對正常細胞之傷害。實驗室先前結果已顯示,在光動力殺菌之後添加幾丁聚醣,可提升光動力殺菌作用、抑制細菌生長。因幾丁聚醣性特可能會受到溶劑的影響而有所不同,所以本論文中將幾丁聚醣溶於不同的有機酸中,藉以觀察其對光動力殺菌之影響。本研究發現,單獨將酸或幾丁聚醣與菌體處理,並不會影響菌體的生長。於光動力作的後加入幾丁聚醣溶於不同配方的乳酸及乳酸/抗壞血酸中,可增加對金黃色葡萄球菌的殺菌效益,對於對抗綠膿桿菌的殺菌效果則更顯著。

並列摘要


Photodynamic inactivation (PDI) of microorganism is a promising technique that helps in the treatment of bacterial infections. PDI has been widely researched and has proven to be effective against gram-positive, gram-negative bacteria and fungi as well as antibiotic-resistant strains. Evidence regarding repeated photosensitization of bacteria suggests that it doesn’t induce resistance. Usually the approach requires high doses of a photosensitizer (PS) and high fluency of light which may induce some harm on human cells. Improvement of the current strategy will lead to an optimal approach that could require very low concentration of the photosensitizer used in PDI .Chitosan, a cationic biopolymer, has shown to aid in PDI and increase the efficacy against microorganism. Since chitosan properties may be affected by the solvent system, in this study we propose to investigate the effect of solvents for chitosan on the photodynamic inactivation for eradication of microorganism. Chitosan was dissolved in selected organic acids and their mixture; we studied the effect that it had on photodynamic inactivation. No effect on bacterial growth was seen when added the acid alone or when chitosan was added without irradiation. Chitosan dissolved in formulations of lactic and lactic/ascorbic acid helped augmenting the antimicrobial effect on Staphylococcus aureus when added after PDI. While chitosan dissolved in formulations of lactic/acetic acid and citric/acetic acid had a better effect on Pseudomonas aeruginosa.

參考文獻


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