Patent ID: 8541013

Claim:
An amphiphilic block copolymer comprising at least three types of monomeric units, said three types of monomeric units comprising: a temperature-sensitive monomeric unit, wherein the temperature-sensitive monomeric unit imparts temperature-induced phase separation character to the amphiphilic block copolymer, a hydrophilic monomeric unit, wherein the hydrophilic monomeric unit has one or more polar functionalities, and a hydrophobic monomeric unit comprising at least one pH-sensitive moiety; wherein said hydrophobic monomeric unit is derived from a copolymerisable unsaturated fatty acid; wherein said unsaturated fatty acid imparts hydrophobic character to the amphiphilic block copolymer; wherein the fatty acid comprises 5 to 50 or more main chain carbon atoms; wherein the fatty acid comprises one carbon-carbon double bond (monounsaturated); and wherein the amphiphilic block copolymer exhibits a lower critical solution temperature (LCST) dependent on environmental pH.