THEORETICAL PREDICTION OF PHASE BEHAVIOR OF BINARY MIXTURES OF PHOSPHATIDYLCHOLINES FROM THE STUDY OF ZETA POTENTIAL

MB SIERRA; VI PEDRONI; BUFFO, F.E.; MA MORINI

Comodoro Rivadavia

Congreso; VI MACI 2017 - Sexto Congreso de Matemática Aplicada, Computacional e Industrial; 2017

Thermotropic behavior of unilamellar liposomes prepared from binary mixtures of phosphatidylcholines inaqueous suspensions was analyzed by means of the temperature dependence of the Zeta Potential (ZP). This techniquepresents high sensitivity and small amount of sample required, that is, 70% less than that required in the use ofconventional calorimeters. The system chosen, dipalmitoylphosphatidylcholine / dimyristoyl phosphatidylcholine(DMPC/DPPC), is one of the binary phospholipidic mixtures in mimic biological membranes most studied. In thispaper a mathematical model is proposed to predict the thermotropic behavior of the system from a few experimentaldata, therefore the transition temperature for other compositions can be obtained. Graph of phase boundaries for thesemixed-lipid vesicles was constructed by plotting the delimiting temperatures of the main phase transition as a functionof the lipid composition of the vesicle. This method would be a simple and useful tool for studying more complexmixtures.