Patent ID: 8217015

Claim:
A method for delivering a polynucleotide to the cytoplasm of a cell comprising: a) forming a first membrane active polyvinylether polymer having the formula: wherein R1 contains an amine group, R2 is an alkyl or aryl group, and x and y are integers greater than zero; b) forming a second membrane active polyvinylether polymer capable of causing liposome leakage having the formula: wherein R1 contains an amine group, R2 is an alkyl or aryl group, and x and y are integers greater than zero; c) reversibly modifying the second membrane active polyvinylether polymer via covalent linkage of a plurality of carboxydimethylmaleic anhydrides to amines on the polymer thereby forming a negatively charged reversibly inhibited membrane active polymer, wherein: i) the reversibly inhibited membrane active polymer is not capable of causing liposome leakage, and ii) exposure of the reversibly inhibited membrane active polymer to acidic pH results in cleavage of the disubstituted maleic anhydride from the second membrane active polyvinylether polymer; d) associating said polynucleotide with the first amine-containing amphiphilic polyvinylether polymer to form a binary complex; e) associating said binary complex with the reversibly inhibited membrane active polymer to form a ternary complex; and f) contacting the cell with the ternary complex resulting in delivery of the polynucleotide to the cell.