Patent ID: 7358223

Claim:
A polymer comprising a recurring unit selected from the group consisting of formula (Ia) and formula (Ib): wherein: PEI is a polyethyleneimine recurring unit; R is selected from the group consisting of an electron pair, hydrogen, C 2 -C 10 alkyl, C 2 -C 10 heteroalkyl, C 5 -C 30 aryl, and C 2 -C 30 heteroaryl; L is selected from the group consisting of C 2 -C 50 alkyl, C 2 -C 50 heteroalkyl, C 2 -C 50 alkenyl, C 2 -C 50 heteroalkenyl, C 5 -C 50 aryl; C 2 -C 50 heteroaryl; C 2 -C 50 alkynyl, C 2 -C 50 heteroalkynyl, C 5 -C 50 aryl; C 2 -C 50 heteroaryl; C 2 -C 50 carboxyalkenyl, C 2 -C 50 carboxyheteroalkenyl; C 12 to C 18 fatty acid, cholesterol, a C 12 to C 18 fatty acid derivative and a cholesterol derivative; W is a cationic moiety comprising from about 2 to about 50 carbon atoms; and m is an integer in the range of about 1 to about 30.