Fig. 3: Characterization and protective effect of chitosan/β-sodium glycerophosphate hydrogel loaded with aMV.

a Schematic for the viral aerosol interception mechanism of chitosan/β-sodium glycerophosphate hydrogel (GEL) loaded with aMV (aMV@GEL). b CLSM image of aMV@GEL showing aMVs were embedded in the network of GEL. Red: DiD labeled aMV; Cyan: FITC labeled GEL. c Scanning electron microscope (SEM) image of aMV@GEL. aMVs were marked with false color (red). d Photographic images of aMV@GEL showing aMV@GEL was in the liquid state at room temperature (RT, 25 °C) and transformed to the gel state at 37 °C. e Photographic image of spray characteristic of aMV@GEL and corresponding spray area formed on the paper 10 cm away from the sprayer. f Schematic design for evaluating the interception effect (left), fluorescence images of the tube precoated with PBS, aMV, GEL, or aMV@GEL after nebulizing cyanine 5 N-hydroxysuccinimide ester (Cy5) stained SPV (wild-type) aerosols into the left entrance end (middle), and corresponding fluorescence images of cut view site (indicated by the red arrow, right). g, h Fluorescence quantitative analysis of different sites in tubes of f (g) and relative passing rate of SPV aerosols through these tubes (h). i Schematic and corresponding CLSM images illustrating the detailed process of SPV (wild-type) aerosol interception and virus entrapment by aMV@GEL. (i) The drops of viral aerosols consisting of water and SPV. (ii) The top view of viral aerosols contacting the aMV@GEL (0 min). (iii) The top view of viral aerosols fusing with aMV@GEL (10 min). (iv) The entrapment of the released SPV by aMV inside GEL (60 min), which image was captured at a distance of 15 μm from the surface of the GEL. Purple: fluorescein sodium-stained water in viral aerosols; Green: cyanine 3 N-hydroxysuccinimide ester (Cy3) stained virus in viral aerosols; Red: Cy5 stained aMV; Cyan: FITC-stained gel. Quantitative data in h represents as mean ± S.E.M., n = 3 biologically independent experiments. Statistical significance was calculated using one-way ANOVA with multiple comparison tests. All significant P-values are indicated. Source data are provided in the Source data file.