Figure 4. Analysis of scanning electron microscope imaging. Analysis of one-month-old specimens from the SAM R1 and the SAM P8 experimental groups (A and B, respectively) displayed the morphology of endothelial cells, which was hexagonal and uniform, with numerous microvilli located on the surface. Analysis of six-month-old specimens from the SAM R1 and the SAM P8 experimental groups (C and D, respectively) showed that the endothelial cells became larger and pantomorphic. Analysis of 12-month-old specimens from the SAM R1 and the SAM P8 experimental groups (E and F, respectively) showed more polygonal cells, and these cells also became larger. Scale bars: 10 μm.