A COMPARATIVE-STUDY ON THE IMMUNE-RESPONSES TO ANTIGENS IN PLA AND PHB MICROSPHERES

Biodegradable microspheres, prepared from various polymers, and contai ning a model antigen, BSA, were prepared using a double emulsion solve nt evaporation method. The microspheres, consisting of poly(L)lactide, poly(DL)lactide, poly(DL)lactide-co-glycolide, polyhydroxybutyrate of various molecular weights and polyhydroxybutyrate-co-valerate, were c haracterised for their size distribution, drug loading, release kineti cs, surface morphology and hydrophobicity. The influence of these prop erties on the dynamics of the immune response, following i.m. administ ration, was studied. The hydrophobic nature of polyhydroxybutyrate mic rospheres, compared with those formed using polylactides was confirmed and the generation of a significant immune response was delayed using these preparations. Also, the time course of immune responses generat ed using a range of polyhydroxybutyrate molecular weights was examined . (C) 1997 Elsevier Science B.V.