ELECTROPERMEABILIZATION OF PERIPHERAL-BLOOD PHAGOCYTES INDUCES A LONG-LIVED CELL-MEMBRANE ALTERATION WHICH DOES NOT AFFECT THEIR VIABILITY

Electropermeabilization is an efficient tool for introduction of molecules into cell cytoplasm. Blood cells can then be loaded with drugs to build new immunocompatible vehicles. The aim of this study was to evaluate the functional modifications of electropulsed phagocytes by monitoring the oxygenating activities. Chemiluminescence measurements were performed on blood samples after stimulation (addition of phorbol myristate acetate or opsonized zymosan). Results show that: when ten pulses of 1.6 kV cm(-1) lasting 100 mu s were applied (resulting in permeabilization of 70% of leucocytes and 44% of membrane area), an alteration in the peak of chemiluminescence and in the delay time of the reaction are observed, after phorbol 12-myristate 13-acetate stimulation. Pulsation under other conditions (two pulses of 1.2 kV cm(-1) lasting 1 ms) led to the same permeabilization yield but affected a smaller cell membrane area (25%) and did not impair oxygenating activities for either stimulation. Results were similar if stimulation was triggered 7 h after electropulsing. A long-lived functional alteration is present when strong fields with short duration are used, affecting a large cell surface. Low-field long-pulse electropulsation led to better preservation of physiological. integrity of the permeabilized phagocytes.