3.3. ESEM observations
In this study, ESEM was used to observe the formation and interconnected network structures of the MBH preparations. Fig. 3 shows ESEM images of the blank MBH preparation with different concentrations of Poloxamer 407 (Fig. 3A–C) and the triptolide-loaded MBH preparation with 16% (w/w) Poloxamer 407 ( Fig. 3D).