以微胞包埋chlorin e6之光動力殺菌研究

Photodynamic inactivation against bacteria and fungi by micellar chlorin e6

陳玫延(Mei-Yan Chen)

指導教授 ： 陳進庭

國立臺灣大學/生命科學院/生化科技學系/碩士(2013年)

https://doi.org/10.6342/NTU.2013.11160

摘要

日常環境周遭甚至人體身上存在的許多伺機性感染源易感染免疫力本身就低的住院病人，且對其威脅性高。這些病原菌的治療傳統上是使用抗生素，但近年來抗生素濫用導致的抗藥性問題日益嚴重。光動力治療（photodynamic therapy, PDT）應用於感染性疾病治療又稱為光動力殺菌（photodynamic inactivation, PDI），使用於PDI之光感物質中有許多屬於疏水性物質，其於水相溶液中的聚集現象會降低PDI效應。本研究以疏水性光感物質chlorin e6（Ce6）為對象，期望透過微胞（micelle）包埋的策略改善此一問題並增進對三株院內感染常見菌株之PDI效應。菌株分別為革蘭氏陽性菌之金黃色葡萄球菌（Staphylococcus aureus）、革蘭氏陰性菌之綠膿桿菌（Pseudomonas aeruginosa）、真菌之白色念珠菌（Candida albicans）。吸收和螢光光譜、粒徑、Ce6回收率等特性分析結果顯示，三種微胞材料Pluronic P123、Lutrol F127、Synperonic L121中P123最適於Ce6的包埋，此劑型確實能增進對S. aureus之光動力殺菌效果，但對P. aeruginosa和C. albicans仍效果不佳，micelle form Ce6之Reactive oxygen species（ROS）產率較高，但與S. aureus結合量較低，可知微胞的包埋能透過分散Ce6分子增進PDI效應。為增進另外二株菌之PDI效果，改良微胞配方為帶正電荷P123-CTAB micelle Ce6，此一劑型增進了對C. albicans而非P. aeruginosa的PDI效果，由C. albicans與Ce6分子結合量分析結果推測雖然攝入較多free form Ce6但其於菌體內仍為聚集狀態，導至PDI效應不佳。最後我們將帶正電荷micelle Ce6應用於S. aureus和C. albicans生物膜之PDI測試，推測由於extracellular matrix之保護使PDI效果仍不佳。

關鍵字

光動力殺菌 ； chlorin e6 ； 微胞 ； Pluronic P123 ； 金黃色葡萄球菌 ； 綠膿桿菌 ； 白色念珠菌

並列摘要

Opportunistic pathogens will cause disease when the function of immune system is reduced. Due to the extensive use of antibiotics, drug-resistant microbia spread fast. Photodynamic inactivation (PDI) is a potential treatment for infectious disease. Most of the photosensitizers (PSs) are hydrophobic and easy to aggregate, which will reduce the PDI efficacy. To increase the PDI efficacy, we encapsulated chlorin e6 (Ce6) into micelle and explored the PDI efficacy of micellar Ce6 against Gram-positive bacteria Staphylococcus aureus, Gram-negative bacteria Pseudomonas aeruginosa, and fungus Candida albicans, as well as the biofilm. The UV-Vis and fluorescence spectrophotometric spectra show that the three materials PF127, L121 and P123 can successfully encapsulate and disperse Ce6. Micellar Ce6 can improve PDI efficacy to S. aureus, but not to P. aeruginosa and C. albicans. Though P123 micelle Ce6 can produce more reactive oxygen species, their binding to S. aureus was less compared to free-form Ce6.
To improve the PDI efficacy against P. aeruginosa and C. albicans, cationic P123-CTAB micelle Ce6 was developed. No dark toxicity was found in P123-CTAB micelle Ce6 but cause significant killing against C. albicans after light irradiation. Compared to free-form Ce6, P123-CTAB micelle Ce6 induce higher PDI effect, though C. albicans uptake higher content of free-form Ce6. The lower PDI efficacy might relate to the aggregation of free Ce6. Finally, we found that P123-CTAB micelle Ce6 can not improve PDI efficacy against the biofilms of S. aureus and C. albicans, which might relate to the protection of extracellular polymeric substances (EPS).

並列關鍵字

Photodynamic inactivation ； chlorin e6 ； micelle ； Pluronic P123 ； Staphylococcus aureus ； Pseudomonas aeruginosa ； Candida albicans

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