Objective To prepare
biodegradable PLA/PLG
microspheres used for encapsulating ribonucleoprotein(RNP)and study on the effect
of it as an adjuvant.Methods
Biodegradable PLA/PLG
microspheres were prepared, and the quality of them were evaluated using protein loading, encapsulation rate, shape and size as indexes. The hydrolysis and release of the microspheres prepared with 3 kinds of materials were observed at 37℃ in vitro, and the immune effects of them were compared.Results At the 2nd to 4th week after immunization, the antibody titer of PLG50/50 microsphere was 2 times higher than those of PLA and PLG85/15 microspheres, and, at the 8th week, the titer of PLA microsphere reached peak value. However, all the antibody titers induced by the 3 kinds of microspheres were 5 times higher than that induced by RNP without encapsulation. The anti NP level induced by a single dose of RNP encapsulated with PLA/PLG microsphere was similar to that induced by 2 doses of RNP using Al(OH) 3 as adjuvant. However, the level was significantly higher than that induced by RNP without any adjuvant.Conclusion PLA/PLG microsphere is a good adjuvant of RNP and worth further investigation.