Effects of 2.45-GHz microwave and 100-MHz radiofrequency radiation on liposome permeability at the phase transition temperature.
Bioelectromagnetics 1988; 9(3):249-257
The effects of 100MHz continuous wave (CW) radiofrequency and 2.45 gigahertz (GHz) CW microwave radiation on liposome permeability and phase transition temperatures were investigated. Liposome vesicles loaded with tritiated cytosine-arabinofuranoside (ARA-C) were prepared by a reverse phase evaporation process from two purified, saturated phospholipids, dipalmitoylphosphatidylcholine (DPPC) and dipalmitoylphosphatidylglycerol (DPPG). The liposomes were then exposed for 30 minutes to 60 watt/kilogram (W/kg) CW 100 megahertz or 2.45GHz radiation in-vitro at temperatures from 37 to 43 degrees- C. Liposomes were exposed in HEPES buffer or in HEPES buffer supplemented with 44 percent by volume fetal calf serum (FCS). At temperatures between 39 and 40 degrees-C with the FCS present, characteristic phase transition responses were noted. Under these conditions the maximum percent release of tritium labeled ARA-C was increased by 20 percent relative to HEPES suspension. No detectable effect on liposome permeability or the location of the phase transition in the presence or absence of FCS was altered by either frequency of electromagnetic radiation.
BIOEDI; NIOSH-Publication; NIOSH-Grant; Electromagnetic-fields; Electrical-fields; Magnetic-fields; Drug-therapy; Plasma-membrane; Chemotherapy; Nonionizing-radiation
Physiology and Biophysics Medical College of Virginia Box 694, Mcv Station Richmond, VA 23298
Virginia Commonwealth University, Richmond, Virginia