RESUMO
Objective·To prepare a bacterial outer membrane vesicle (OMV) coated poly (lactic-co-glycolic acid) copolymer (PLGA) nanoparticle loaded with ovalbumin (OVA) and evaluate its intranasal immune effect in mice.Methods· OMV was prepared by ultrafiltration concentration method.OVA loaded PLGA nanoparticle (NP) was prepared by emulsion-solvent evaporation method.OMV coated PLGA nanoparticle (OMV-PLGA NP) loaded with OVA was prepared by extrusion method and characterized.BALB/c mice were intranasally immunized and specific sIgA levels in nasal wash,jejunum and fecal pellet were determined by ELISA.Results· Size of OVA loaded OMV-PLGA NP was (234.4±22.9) nm.The shell-core structure of OVA loaded OMV-PLGA NP was proved by transmission electron microscope.After 14 d of administration,sIgA antibody levels in nasal wash,jejunum and fecal pellet of OVA loaded OMV-PLGA NP treated group were the highest in all treated groups.Compared with the group treated with OMV and OVA,OVA-specific sIgA antibody level in nasal wash,jejunum and fecal pellet of OVA loaded OMV-PLGA NP treated group was increased 1.6,2.1 and 1.7 times,respectively.Compared with the group treated with OMV and OVA,OMV-specific sIgA antibody level in nasal wash,jejunum and fecal pellet of OVA loaded OMV-PLGA NP treated group was all increased 1.5 times.Conclusion· This novel nanoparticle drug delivery system can simultaneously delivery OVA and OMV to antigen presenting cells,resulting in stronger mucosal immune response in mice.