TABLE 4.

Hybrid structures used in the formulation of biologically-derived nanoparticles.

Hybrid structure	Formulation	Target pathogen	Reference
Micron-size particles	Recombinant OMV containing M2e antigens derived from Clearcoli® encapsulated in PLGA microparticles	Influenza	Watkins et al. (2017a)
	Porcine circovirus type 2 VLPs encapsulated in chitosan microparticles	Porcine circovirus type 2	Bucarey et al. (2014)
	OMVs isolated from Neisseria meningitidis encapsulated in dextran- or mannan-based microspheres	Neisseria meningitidis	Arigita et al. (2004)
	Foot-and-mouth disease VLPs encapsulated in liposomes	Foot-and-mouth disease	Kim et al. (2020)
	Bacteriophage-based (f3) VLPs encapsulated in PLGA microparticles	None	Jamaledin et al. (2020)
Polymeric gel	M2e VLPs encapsulated in a polymeric matrix	Influenza	Gomes et al. (2021)
	Lyophilized OMVs derived from heat treated Shigella flexneri ΔtolR bacteria, encapsulated in a polymeric matrix	Shigella flexneri	Pastor et al. (2020)
Nano-sized particles	Foot-and-mouth disease VLPs complexed with gold nanocages	Foot-and-mouth disease	Teng et al. (2021)
	OMVs isolated from Bordetella pertussis encapsulated in sodium alginate nanoparticles	Bordetella pertussis	Rami et al. (2021)