Figure 4.

Physical stability, pDNA protection, and transcytosis capability of CS‐g‐bPEI/pDNA NPs in distinct in vitro environments that simulate their transport through GI tract. Physical stability of NPs at various pH conditions: A) TEM images and B) particle size and zeta potential; C) pDNA protection of NPs in various pH environments and nuclease digestion using DNase I and lysozyme. Transcytosis capability of NPs in Caco‐2 cell monolayers at 4 or 37 °C, evaluated by D) reduction of TEER, E) transcellular penetration, visualized using constructed 3D CLSM images, and F) P _app values. Black arrows indicate direction from apical layer to basolateral layer. *: Statistically significant (P < 0.05).