Effect of hydrophobic octadecyl groups on ph-sensitive aggregation behavior of imidazole-containing polyaspartammide derivatives

The effect of hydrophobic octadecyl groups on pH-dependent aggregation behavior of polyaspartammide derivatives was studied. A series of pH-sensitive amphophilic polymers with different degrees of octaceylamine (C18) 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 C18 chains. These polymers will have a potential application as carriers for pH-sensitive drug release in anticancer or intracellular delivery systems.