Use of voltage pulses for the pore opening and drug loading, and the subsequent resealing of red blood cells.

Electric pulses in the range of 1 to 5 kV/cm and of durations 1 to 200 microseconds have been used to open up pores of limited size in various cell types. In the case of erythrocytes, these pores were shown to admit molecules as large as tetrasaccharides. Loading of clinically active drugs has also been attempted. Erythrocytes loaded with drugs can be resealed without loss of the hemoglobin content. With mouse erythrocytes, we have demonstrated the feasibility of using erythrocytes (not hemoglobin depleted ghosts) as drug carriers for prolonging the drug level in the circulation. Other possible applications of the method are also discussed.