A) BMA/DMOEP copolymer isolated from DOPC liposomes stored at pH 7.4, followed by overnight suspension in acidified THF. B) BMA/DMOEP copolymer isolated from DOPC liposomes stored at pH 7.4, followed by overnight suspension in neutral THF. C) BMA/DMOEP copolymer isolated from DOPC liposomes stored at pH 2.0, followed by overnight suspension in neutral THF. D) BMA/DMOEP copolymer isolated from DOPC liposomes, resuspended in pH 2.0 aqueous buffer overnight. E) Optical density measurements for samples collected following overnight incubation in THF as described in A), B) and C). Measurements were made at 330 nm.