ABSTRACT
We constructed and optimized the plasmid DNA (pDNA) Opt-S encoding the gene of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein, using poly (lactic-co-glycolic acid) copolymer (PLGA) as a delivery carrier for pDNA. PLGA-pDNA NPs were loaded by nanoprecipitation and its properties in vitro were preliminary evaluated. The results showed that the prepared PLGA-pDNA NPs were regular morphology, clear edges, with an average particle size of (184.2 ± 2.4) nm, polydisperse index (PDI) of 0.093 ± 0.013, zeta potential of (-68.10 ± 0.36) mV, and encapsulation rate of (98.92 ± 0.22)%. The PLGA-pDNA NPs were stable at -20 ℃ for 7 months and could protect pDNA against nuclease degradation. And they also exhibited sustained release of pDNA in vitro. The PLGA-pDNA NPs have low cytotoxicity and high safety. In addition, in vitro transfection experiments showed that the SARS-CoV-2 S gene could enter cells and be expressed. These results indicate that PLGA-pDNA NPs non-viral gene vector have simple preparation process and good performance, which are expected to provide a new idea for the research and development of SARS-CoV-2 vaccine.
ABSTRACT
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.
ABSTRACT
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.