Effect of Hydrophobic Octadecyl Groups on pH-Sensitive Aggregation Behavior of Imidazole-Containing Polyaspartammide Derivatives

Abstract

The effect of hydrophobic octadecyl groups on pH-dependent aggregation behavior of polyaspartammide derivatives was studied. A series of pH-sensitive amphiphilic polymers with different degrees of octaceylamine (018) substitution were synthesized through a successive graft reaction of octaceylamine, O-(2-aminoethyl)-O'-methylpolyethylene glycol, and 1-(3-aminopropyl)imidazole on polysuccinimide. Micelle-like nano-aggregates were formed in aqueous solution at pH > 6.8 and they showed different pH dependent aggregation behavior according to degree of substitution (DS) of the hydrophobic 018 chains. These polymers will have a potential application as carriers for pH-sensitive drug release in anticancer or intracellular delivery systems.