pH-sensitive self-assembling property of poly(ethyleneimine)/cinnamic acid mixture and its effect on pH-dependent release of monoolein cubic phase

摘要

Poly(ethyleneimine) (PEI)/cinnamic acid (CA) mixture was self- assembled into microsphere in aqueous phase. As the pH value increased, the self- assembly became hardly formed. As the molar ratio of the amino group of PEI to the carboxyl group of CA increased, the pH window for the formation of self- assembly became broader. The phase transition temperature of cubic phase was 58.5-67.5 degrees C, depending on the PEI/CA content. The release of dye loaded in cubic phase containing PEI/CA increased in a first- order fashion. The release degree was higher at a lower pH value.