Painless Vaccinations with Iontophoresis 2009/09/10 Professor Kentaro Kogure of Kyoto Pharmaceutical University and a group from Hokkaido University have succeeded in combining antigenic proteins with electrically charged ribosomes to transfer substances into the skin by using electricity. The method has already been used to administer insulin to diabetic rats, after which declines in blood sugar were confirmed.

Kogure’s study was an attempt to use ribosomes combined with iontophoresis as a means to transfer antigens with larger molecules. The ribosomes (spherical lipid bilayers) used were charged, and microparticulated with antigenic protein (in this case, ovalbumin). They were then transferred into the rat’s skin using iontophoresis. The antigenic protein was transmitted to the interior layers of the skin, and an immune response (antibody production) was successfully elicited.

Administration of a drug by injection is a more effective way of delivering the drug than oral administration, in which the drug is metabolized by the liver. Injections are therefore widely used, but since they involve a needle there is some resistance from patients. Injections also cause shock symptoms in rare cases. These problems can be overcome if iontophoresis is more widely used.

Today insulin administration and vaccinations are all done with injections. If administration with iontophoresis becomes practical, treatment for infections, treatment or prevention of AIDS or cancer, and general purpose vaccinations can all be done with less burden on the patient. This method of administration is currently at the animal experiment stage, but early practical application is anticipated. (Koji Fujiyoshi)