Figure 4.

Cationic polymers do not induce efficient small molecule vesicle leakage in POPC vesicles. A) The fluorophore ANTS is quenched by close proximity quencher DPX when encapsulated in vesicles, but becomes fluorescent upon effective membrane poration. A higher fluorescence signal signifies a greater degree of leakage. B) PBAE 447 induced minor leakage of ANTS/DPX from POPC lipid vesicles at pH values of 6 and 7 but not pH 5. C) BPEI 25 kDa did not induce any meaningful leakage at either pH 5 or pH 7. Normalized vesicle leakage is reported relative to vesicles from the same prepared batch exposed to Triton X-100 to induce complete membrane leakage. The dotted line indicates vesicle leakage caused by mellitin, as approximated from the results of Wiedman et al.²⁵