DODAB-DOPE liposome surface coating using in-situ acrylic acid polymerization

Abstract In situ acrylic acid (AA) polymerization reaction at liposome surface was performed using as initiator H2O2/ascorbic acid, obtaining DODAB:DOPE/ poly(acrylic acid) nanocapsules. The AA adsorption dependence onto liposome interface was measured as a function of pH and AA concentration. The AA adsorption was quantified at ≥ pH 4.4 and concentrations >2.0 mmol.L−1. Moreover, the effect of the liposome size was evaluated by AA conversion to poly(acrylic acid) and the reaction kinetics was elucidated. While for larger liposomes (200 nm) the AA conversion reduced, for the smaller ones (20 nm), the polymerization kinetics was similar to homogeneous conditions. The interfacial polymerization efficiency was demonstrated to be dependent on the pH and AA concentration and related to the liposome superficial area. Further, the conversion was dependent on liposomes size, but not on its concentration, in a small concentration range. AFM images showed a shape modification in the liposome after polymerization and indicated a nanocapsule formation. The molar masses of the polymers formed were affected by the liposome presence. It was possible to modify the liposome interface using in-situ polymerization and stablishing the major parameters associated to the polymerization.