Outer Membrane Vesicles of Bordetella pertussis Encapsulated into Sodium Alginate Nanoparticles as Novel Vaccine Delivery System

Abstract

Background: Outer membrane vesicles (OMVs) release from Gram-negative bacteria and are interesting alternatives that can replace those vaccines that contain naturally incorporated bacterial surface antigens, lipopolysaccharides (LPS) and outer membrane proteins (OMPs). Nanoparticles can be used to encapsulate vesicles for slow release and prevent macromolecular degradation. Objective: Therefore, encapsulation of OMVs of B. pertussis into sodium alginate nanoparticles was the main aim of the current study. Method: The OMVs of B. pertussis extracted and characterized by particle sizer, electron microscopy, SDSPAGE and Western blot assays. The extracted OMVs were encapsulated in sodium alginate nanoparticles (OMV-NP) using unique gelation process and injected into BALB/c mice. Immunogenicity indices such as different classes of antibodies and interleukins related to different T cell lines were evaluated in immunized mice by ELISA. The respiratory challenge was evaluated in the groups of mice. The existence of pertussis toxin (PTX), filamentous haemagglutinin (FHA) and PRN (pertactin) in B. pertussis OMVs was verified using SDS-PAGE and Western blot analysis. Results: TEM electron microscopy showed the size of these OMVs to be around 20-80 nm. The OMVs with appropriate quality were encapsulated into sodium alginate nanoparticles (OMV-NP), and the final size was about 500 nm after encapsulation. Immunity indices were significantly higher in the OMV-NP receiving group. In challenge tests, the OMV-NP vaccine was able to show the highest rate of lung clearance compared to the control groups (OMV and wPV) at the lowest injection dose. Conclusion: The results indicate the potential of OMV-NP as a novel vaccine delivery system.

Biological Nanoparticles in Vaccine Development

“…Formulation of biologically derived nanoparticles into larger nanoparticle systems, rather than microparticles, has also been used to enhance immunogenicity ( Rami et al, 2021 ; Teng et al, 2021 ). Gold nanocages (AuNCs) were recently used as a carrier for foot-and-mouth disease VLPs ( Teng et al, 2021 ).…”

Slow-sculpting graphene oxide/alginate gel loaded with platelet-rich plasma to promote wound healing in rats

“…In sodium alginate, sodium ions are exchanged with polyvalent metal cations, crosslinked to form hydrogels with good permeability, which has a significant effect on maintaining the activity of cells, enzymes, sensitive drugs, proteins and other substances ( Sanchez-Fernandez et al, 2021 ). So, it is widely studied in the fields of tissue repair materials, biochemical drug-controlled release carriers, cell immune isolation and other tissue engineering ( Kumar et al, 2019 ; Zhu et al, 2020 ; Liu et al, 2021 ; Rami et al, 2021 ; Shiny et al, 2021 ; Wang et al, 2021 ; Zhang et al, 2021 ). Although alginate (Alg) is currently widely used in clinical practice, and one of the most effective dressings, but there are still many deficiencies in clinical application.…”