[Study of interaction between the phase states of liposome and dyes by UV-visible absorption spectra].

Liposome is one of the major areas of interest in recent years because of its many potential applications. In this paper, three phase states of liposome (micelle, lamellar and reversed hexagonal) were prepared by thin-film hydration method and their structures were observed with electron microscope. We studied the interaction between these phase states and various dyes by UV-visible spectra. As a result, the phase states of liposome can be detected by the color change or the spectroscopic change. Through careful selection, 4 kinds of useful dyes were found to detect different liposome structures, that is 2,6-dichloroindophenol sodium, congred, pinacyanol chloride and calcein. The possible mechanism of the interaction between the phases of liposome and dyes was discussed. The liposome undertakes hydrolysis and forms mixed micelle. The hydrolysis rate of lamellar is faster than that of reversed hexagonal, which makes pH of the solution to decrease and causes a color change of the dyes in a short time. This method can be applied to the separation of natural phosphatides and monitor in the production of liposome.