Figure 2

TEM image for (A) blank PHs prepared with PBS (pH7.4) by FH method (B) blank PHs prepared with PB (pH5.5) by FH method, (C) blank PHs prepared by EI method, and (D) SEM image of lyophilized PHs at magnification power of 7500. The scale bar in images A, B, and C is 500 nm and in image D is 1 µm.