AVS 57th International Symposium & Exhibition
    In Situ Microscopy and Spectroscopy Topical Conference Wednesday Sessions
       Session IS+BI+AS-WeA

Paper IS+BI+AS-WeA1
Adsorption and Phase Transition of Liposomes via Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy

Wednesday, October 20, 2010, 2:00 pm, Room Acoma

Session: In Situ Microscopy/Spectroscopy – Biological Interfaces
Presenter: M.R. Hernandez, University of California at Davis
Authors: M.R. Hernandez, University of California at Davis
T.C. Ng, University of California at Davis
E.N. Towns, University of California at Davis
B.C. Walsh, University of California at Davis
D.P. Land, University of California at Davis
Correspondent: Click to Email
Liposomes are becoming increasingly prevalent as an important part of drug delivery systems in modern medicine, however a better understanding of the physical characteristics is needed. In this study we present our results on the stability and adsorption of liposomes formulated from dipalmitoylphosphatidylcholine (DPPC) via attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The phase transition temperature of liposome formulations of pure DPPC, DPPC and cholesterol, and DPPC, cholesterol, and 1,2-Distearoyl-phosphatidylethanolamine-methyl-polyethyleneglycol -2000 (DSPE-mPEG2000) is determined using a temperature dependant study (25°C to 50°C) and been found to occur abruptly around 41°C for pure DPPC liposomes and exhibit gradual temperature changes from 35°C to 43°C for the other two liposome formulations. We have studied the adsorption characteristics of different formulations of liposomes with both hydrophobic and hydrophilic surfaces created by different self-assembled monolayers, and will present a new method for studying an in vitro way of studying the adsorption of different formulations of liposomes onto a surface of immobilized proteins. Knowing the stability of liposomes and liposome-protein adsorption characteristics allows for a better understanding of their use and design of future formulations in drug delivery systems.