IN-VITRO STUDY OF ALCOHOL-DEHYDROGENASE AND ACETALDEHYDE DEHYDROGENASE ENCAPSULATED INTO HUMAN ERYTHROCYTES BY AN ELECTROPORATION PROCEDURE

The optimal conditions for electroporated/resealed loading of alcohol dehydrogenase (ADH) and/or acetaldehyde dehydrogenase (ALDH) into huma n erythrocytes were established prior to the study, with the following characteristics: 300 V, 1 ms pulse time, eight pulses every 15 min an d 1 h resealing at 37 degrees C. High encapsulation yield and carrier cell recoveries were achieved. Cell volumes increase while hemoglobin contents decrease; in consequence a decrease in cell hemoglobin concen tration was observed. A lower hypotonic resistance of loading erythroc ytes (throughout osmotic fragility curves) and unaltered oxygen transp ort capability (as given by oxygen equilibrium curves) were observed. The stability against time (up to 168 h-7 days) of encapsulated indivi dual enzymes, either ADH- or ALDH-red blood cells (RBCs), was studied at 4 degrees C and 37 degrees C, in comparison with that of free enzym e solutions. Both enzymes were released from carrier RBCs to the incub ation medium. The stability of carrier RBCs was studied under similar conditions. Non-significant variations in hematological parameters wer e observed. However, the hemoglobin derivative forms showed modificati ons, The continuous degradation of ethanol by ADH-RBCs and coencapsula ted ADH- and ALDH-RBCs, as a function of time (up to 70 h) suggests th e use of these carrier RBCs as agents for complete metabolization of e thanol. The mentioned properties bare the possibility of using ADH and ALDH as carrier systems in in vivo situations. (C) 1998 Elsevier Scie nce B.V. All rights reserved.