Fig. 1

(A) The UreH gene was inserted into the pCI-neo expression vector using XhoI and NotI. (B) The effective synthesis of the recombinant plasmid was verified using electrophoretic extraction of the UreH digestion fragments. 1: pCI-neo-UreH recombinant plasmid before digestion, 2: pCI-neo-UreH recombinant plasmid after digestion, M: Marker III DNA Ladder. (C) Co-transfection of the recombinant constructs to the HEK 293-T cells resulted in 810 bp bands after PCR analyses using specific primers. 1: Negative control, 2: 810 bp bands of UreH gene, M: Marker III DNA Ladder. (D) The number of NPs in each interaction determines the relative fluorescence of pDNA in each sample. Free-pCI-neo has the most fluorescence. Fluorescence intensities decrease in the Alginate/pCI-neo-UreH. (E) Nanoparticle size measurement following storage by freezing at − 20 °C for 1 month. (F) Electrophoretic movement of different formulations of nanovaccines. Lane M: negative control; Lane 1: Free-pCI-neo; Lane 2: Alginate/pCI-neo-UreH; Lane 3: Alginate/pCI-neo. (G) In vitro release kinetic of different formulations of nano vaccines at pH 7. (H) Cytotoxicity of several nano vaccine formulations on HEK-293 cells after 24 h (n = 3; mean ± standard error; ns: not significant; *p ≤ 0.05; **p ≤ 0.01, ***p ≤ 0.001)