Bordetella pertussis antigens encapsulated into N-trimethyl chitosan nanoparticulate systems as a novel intranasal pertussis vaccine

Figures & data

Table 1. Immunization study design.

Groups (n = 20)	Antigens (PTd + FHA) dose (μg)	Volume (μl)	Immunization schedule (day)	Route of administration	Serum sampling and nasal washes (day)
TMC/PTd + FHA nanoparticles	6 + 6	20	1, 28	i.n.	42
Antigens solution	6 + 6	20	1, 28	i.n.	42
Antigens + aluminium hydroxide	6 + 6	100	1, 28	i.p.	42
TMC		20	1, 28	i.n.	42
PBS		20	1, 28	i.n.	42

Figure 1. Schematic diagram of the experimental procedure. The schematic diagram represents the synthesis of N-trimethyl chitosan nanoparticles (N-TMC NPs), Bordetella pertussis antigen loading, intranasal administration, and immunization study carried out in this work.

Figure 2. Transmission electron microscopy micrograph of PTd + FHA-loaded TMC NPs. PTd: pertussis toxoid; FHA: Filamentous hemagglutinin; TMC: N-trimethyl chitosan; NP: nanoparticle.

Figure 3. In vitro release profile of antigen from TMC NPs. TMC: N-trimethyl chitosan; NP: nanoparticle.

Table 2. Characterization of antigen-loaded TMC NPs.

Zeta potential (mV)	Average size (nm)	Polydispersity index	Encapsulation efficacy	TMC (mg/mL)	TPP (mg/mL)
24.2	218.20 ± 16	0.125	90.22 ± 2.56	0.5	1
30.8	252.8 ± 28	0.189	94.74 ± 1.40	1	1
36.2	302.6 ± 42	0.273	94.90 ± 1.23	1.5	1
38.6	424.42 ± 56	0.485	96.12 ± 1.42	2	1

Figure 4. (A) Total anti-PTd and anti-FHA IgG antibody titers in sera of mice in different groups. PTd: pertussis toxoid; FHA: Filamentous hemagglutinin. (B) Anti-PTd and anti-FHA secretory IgA antibody titers in nasal wash of mice in different groups.

Figure 5. The levels of IL-4, IL-17 and IFN-γ release from splenocytes of immunized mice. Values represent the mean ± standard deviation of seven mice per group.