Fig. 5. Characterization of the porous structure and pore interconnectivity of the biomimetic UHANWs/Col porous nanocomposite with 66.7 wt% UHANWs: (a) digital image of the UHANWs/Col porous nanocomposite; (b–e) the permeable performance of the alamarBlue cell viability assay reagent from the top to the bottom of the UHANWs/Col porous nanocomposite; (f) digital images in the cross section from top to bottom of the UHANWs/Col porous nanocomposite.