Figure. 6. The surface property effect of nanoparticles: A. Hydrophilic / hydrophobic surface distribution affects the penetration efficiency, reproduced from Reference67 with permission from Copyright © 2016, Springer Nature. B. The surface charge property of nanoparticles affects the cell membrane deformation, reproduced from Reference60 with permission from Copyright © 2016, American Chemical Society. C. The relationship between nanoparticle ligand density and cell membrane tension, reproduced from Reference33 with permission from Copyright © 2016, American Chemical Society.