pH-Dependent complexation of poly(acrylic acid) derivatives with phospholipid vesicle membranes

Abstract

Poly(acrylic acid), poly(methacrylic acid), and poly(a-ethylacrylic acid) can be used to modify, in a pH-dependent manner, the properties of phospholipid vesicle membranes. Polymer-lipid complexation causes a decrease in the apparent cooperativity of the lipid melting transition. The "critical pH" for complexation may be controlled through variation of the chemical structure and the tacticity of the poly(carboxylic acid). It is suggested that an important driving force for complexation is provided by the formation of hydrogen bonds between un-ionized carboxyl groups of the polymer and the phosphodiester functions of the lipid surface.

Characterization of pH-Dependent Poly(acrylic Acid) Complexation with Phospholipid Vesicles

“…Hydrogen bonding has been previously suggested to make a contribution to the DISCUSSION interaction of these molecules (4,20). Reduced mobility of Complexation of ace-PAA to phospholipid vesicles at the polymer is most likely due to complexation of PAA acidic pH was investigated using fluorescence spectroscopy.…”

Carboxylated hyperbranched poly(glycidol)s for preparation of pH-sensitive liposomes

“…For example, pH-sensitive amphiphiles, such as oleic acid and cholesteryl hemisuccinate, have been mixed with non-bilayer-forming phospholipid dioleoylphosphatidylethanolamine (DOPE) to yield pH-sensitive liposomes [1,2]. Another efficient method for pH-sensitization of liposome is modification of stable liposomes with pH-sensitive membrane active molecules such as fusion peptides derived from viral fusogenic proteins, or synthetic polymers with carboxyl groups such as poly(alkyl acrylic acid)s [3,4]. Earlier studies by the authors developed a series of carboxylated poly(glycidol) derivatives for pH-sensitization of liposomes [5][6][7].…”

Polymer‐Induced Transient Pores in Lipid Membranes

“…[21] Transient pore formation can be observed with polymer concentrations of 10 mol % relative to the neutral lipid DOPC or DPPC because of membrane adsorption and subsequent insertion by its amphiphilic properties. [22] The observed PEAA channels are cation selective, with a ratio [Na + ]/[Cl À ] ranging from 2-11.…”