ADJUVANT ACTIVITY OF LINEAR ALIPHATIC POLYESTER AND BRANCHED ALIPHATIC OLIGOESTER MICROSPHERES

Bovine serum albumin (BSA) was entrapped into microspheres prepared of terpolymer of DL-lactic acid, glycolic acid and mannitol (GA-M-DLLA), copolymer of Dr-lactic acid and mannitol (M-DLLA) and two lactido-gly colide copolymers (DL-PLGA) by the solvent evaporation emulsion techni que (w(1)/o/w(2)). Release of BSA from the microspheres into PBS, pH 7 .2, or porcine blood serum was examined for 15 weeks and the effects o f blood serum components on the degradation of the microspheres were r ecorded. Subcutaneous administration of a single dose of the microsphe res containing 5 mu g BSA to mice elicited biphasic immune responses i rrespective of the type of the microspheres. Although the interval bet ween the two phases was shorter in the mice treated with the terpolyme r microspheres, adjuvant potencies, assessed in terms of antibody leve ls, were similar for all the four types of the microspheres.