FORMATION AND CHARACTERIZATION OF SIMPLE AND MIXED VESICLES BASED ON MONOMERIC AND OLIGOMERIC PHOSPHATE BIPOLAR AMPHIPHILES

Certain phosphate bipolar amphiphiles, both monomeric (I and II) and p olymeric or rather oligomeric (poly-I and poly-II), were used as basic materials for the preparation of simple and mixed vesicles. Specifica lly, it was found that oligomeric phosphate bipolar amphiphiles form s table vesicles in aqueous media. The same oligomeric bolaamphiphiles i n mixture with their monomeric counterparts also form stable mixed ves icles with sonication; they are relatively less stable with the ''thin film method.'' Furthermore, it was shown that the method of spanning the membrane of didodecylphosphate vesicles with the dipolar amphiphil e II is not effective for enhancing stability. (C) 1995 John Wiley and Sons, Inc.