Figure 2: (a) Gel retardation assay was performed to evaluate maximum gene (siRNA) loading efficiency in the nanoparticles. Lane 1 represents a 10 bp DNA ladder used as a reference. Lanes 2, 3, 4, 5, and 6 represent various N : P ratios tested. The N : P ratio of 129.2 showed optimal siRNA loading with CS-PEG-CP15 polymer solution. (b): TEM image of CS-PEG-CP15/siRNA nanoparticles complexing siRNA at various N : P ratios: (A) 51.6 (mag. 221000x), (B) 77.5 (mag. 122000x), (C) 103.3 (mag. 162000x), and (D) 129.2 (mag. 95800x).