In addition to SAXS, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) are also used. As a microscopic imaging method, TEM analysis reveals the presence and thickness of the lipid layer around the polymer core . Another method is XPS analysis, which deals with the elucidation of the lipid layer on the surface of CSHN systems (i.e., the chemical composition of the interfaces). In this analysis, the elements of the lipid layer on the surface of the nanoparticles are indicated by their unique binding energy values (eV) .