THE POTENTIAL OF POLYMERIC NANOPARTICLES TO INCREASE THE IMMUNOGENICITY OF THE HAPTEN CLENBUTEROL

Micro-and nanoparticles prepared front the biodegradable and biocompat ible polymers poly(lactide-co-glycolide) (PLGA) and polymetylmethacryl ate (PMMA) have been successfully used as immunopotentiating antigen d elivery systems. In our study, this approach was used to improve polyc lonal antibody production to clenbuterol (CBL), a model hapten. PLGA a nd PMMA nanoparticles were loaded with either CBL alone or with a clen buterol-transferrin conjugate (CBL-Tfn) and administered subcutaneousl y to mice. PLGA nano-particles were administered with or without the s aponin adjuvant Quil A. The anti-CBL titres present in experimental se ra were determined by an enzyme immunoassay (ELISA). CBL-Tfn-loaded PL GA nanoparticles co-administered with Quil A had obvious advantages im mmunologically over the currently used method of raising antibodies to CBL (the positive control). The combined adjuvanticity of Quil A and PLGA nanoparticles resulted in a positive response in all four of the mice tested and in higher antibody titles than were seen in the positi ve control group. Furthermore, the sustained release of immunogen from the nanoparticles permitted a reduction in immunizing frequency over the 15-week study period.