An illustration of nanotopography design for plas-mid DNA delivery. (a) A 3D model (top) and an AFM image (bottom) of pDNA-EGFP on a mica surface. (b-g) 3D model images displaying silica nanoparti-cles featured with rambutan- (b), raspberry- (c) and flower-like (d) morphologies and spike (e), hemi-sphere (f) and bowl (g) type subunit nanotopogra-phies conjugated with plasmid DNA at the interface. (h) Schematic representation of pDNA-EGFP DNase I protection, cellular delivery and transfection pro-cess by Rambutan SNPs.