Fig. 4: The morphology of different fiber scaffolds.

a Schematic diagram of amino polylactic acid microsol electrospun fiber and aldehyde cationic liposomes connected with Schiff base. b–d SEM images of different fiber scaffolds (three independent experiments). e–g Histogram of frequency distribution of different fiber scaffolds diameters (n = 100 fibers from each sample). h–j TEM images of different fiber scaffolds (four independent experiments). k–m XPS indicating chemical elements on different fiber scaffold surfaces. n–p AFM images of scaffolds (three independent experiments). The yellow arrows in the images indicate the location of liposome (n = 3, all SEM scale bars were 5 µm, all TEM scale bars were 0.2 µm).