以微脂體或微胞包埋血紫質之光動力殺菌探討

Abstract

為了改善疏水性光感物質於水溶液環境的溶解度及提升光動力效應，並且嘗 試以奈米載體增進光感物質與菌體之間的作用，本研究透過微脂體 (Liposome)或微胞 (Micelle) 包覆光感物質血紫質 (Hematoporphyrin，Hp) 後，藉由光譜及粒徑等相關分析探討Hp載體特性，並進一步比較free form Hp與載體Hp之間的光動力殺菌差異。 吸收與螢光光譜結果顯示，Hp以單體形式 (monomer form) 分布於載體中，粒徑可控制在100 nm大小，Hp奈米載體於低溫儲存至少可維持一個月的穩定。光動力殺菌成果方面，透過載體包埋的Hp劑型本身對菌體無毒性；光動力照光後Hp載體對革蘭氏陽性菌金黃色葡萄球菌、白色表皮葡萄球菌及化膿性鏈球菌之光動力殺菌效果優於free form；但對於革蘭氏陰性菌綠膿桿菌在現有培養條件下存活率則無顯著影響。

To increase photodynamic efficacy and the interaction between photosensitizer and bacteria, we use liposome or micelle to encapsulate Hematoporphyrin. After the encapsulation, we first characterize these nanocarriers by analyzing the spectra and particle size, and then compare the bactericidal differences between free form Hp and carrier Hp. The UV-Vis and Fluorescence spectrophotometric spectra show that, Hp is dispersed in carriers as a monomeric form. The particles sizes of carriers are about 100 nm. And micellar formulations could maintain their storage stability as solution or lyophilized form at least for one month at 4℃. The spectrophotometric spectra remained the same in one month, showing that no chemical degradation took place. Drug content of Hp-loaded Pluronic® micelles did not change in 1 month showing the high storage stability of these formulations. Carrier Hp themselves have no toxicity to bacteria without lighting. Under 50 J/cm2 lighting to Gram-positive bacteria S. aurues, S. epidermidis and S. pyogenes, nano-carriers achieve better phototoxicity than free form Hp, but no effect to Gram-negative bacteria P. aeruginosa survival.