Preparation of carboxyfluorescein liposomes and their response to pathogenic bacteria

Abstract:

[Background] According to the clinical detection of wound infection is time-consuming and expensive, fast and convenient identification is imperative. [Objective] We investigated the stability of the liposomes by adding different components to the liposomal membranes, and their response to bacterial. [Methods] liposome encapsulated carboxyfluorescein were prepared with phosphocholine (PC) as a main lipid constituent, cholesterol, 10,12-tricosadiyonic acid (TCDA), 1,2-dipalmitoyl-sn-glycero-3-phospho-(1?-rac-glycerol) (DPPG), octadecylamine as stabilizing agents by thin-film and rehydration method. The bacterial suspensions and respective supernatants were incubated with fluorescent liposome to obtain the fluorescence increments according to the interaction between toxins and liposomes. [Results] DPPG and TCDA(10,12-Tricosadiyonic acid) increased the stability of the liposome, and octadecylamine decreased it. When incubated with bacterial suspensions and its supernatants of Staphylococcus aureus ATCC25923 and Pseudomonas aeruginosa PAO1, the obvious increase of the fluorescence intensity was observed, while incubated with Escherichia coli DH5α and PBS, the fluorescence intensity almost unchanged. [Conclusion] S. aureus and P. aeruginosa which release exotoxins can lyse liposomes but not by E. coli.

Key words:Carboxyfluorescein, Liposome, Stabilizing agent, Staphyloaoccus aureus, Pseudomonas aeruginosa