The influence of low power microwave on the properties of DPPC vesicles

The effect of microwave exposure on liposome at non-thermal level are studied. Dipalmitoyl phosphatidylcholine (DPPC) liposomes were exposed to 950 MHz at power densities of 2.5 mW/cm2, which is equivalent to specific absorption rate (SAR) of 0.238 W/K. The interaction of microwave with liposomes was investigated by membrane solubilization measurements using a non-ionic detergent, octylglucoside (OG), as well as Fourier transform infrared (FTIR) spectroscopy and flow activation energy measurements. The amount of detergent needed to completely solubilize the liposomal membrane was increased after exposure of liposomes to microwave irradiation, indicating an increased membrane resistance to the detergent and hence a change in the natural membrane permeation properties. In the analysis of FTIR spectra the symmetric and antisymmetric CH2 (at 2070 cm−1) band and the CO (at 1640 cm−1) stretching bands were investigated after liposomal exposure to microwave irradiation. It is clearly shown from the flow activation energy measurements, that low-power microwave induce changes in the liposomes deformability (decreases the liposome fluidity and increases the liposome rigidity). Finally it could be concluded that low-power microwave of 950 MHz induced structural and functional changes in liposomes as a membrane model system.