EFFECT OF MICROWAVE-RADIATION ON THE PERMEABILITY OF CARBONIC-ANHYDRASE LOADED UNILAMELLAR LIPOSOMES

The influence of 2.45 GHz microwave exposure (6 mW/g) on the diffusion processes in enzyme-loaded unilamellar liposomes as bioreactors was s tudied. The enzyme carbonic anhydrase (CA) was entrapped into cationic unilamellar vesicles. Previous kinetic experiments showed a very low self-diffusion rate of the substrate p-nitrophenyl acetate (PNPA) acro ss intact liposome bilayer. A twofold increase in the diffusion rate o f PNPA through the lipid bilayer was observed after 120 min of microwa ve radiation compared to temperature control samples. The microwave ef fect was time dependent. The enzyme activity, as a function of increas ed diffusion of PNPA, rises over 120 min from 22.3% to 80%. The increa se in stearylamine concentration reduces the enzyme activity from 80% to 65% at 120 min. No enzyme leakage was observed. (C) 1994 Wiley-Liss , Inc.