2.4 Stability test of NCs
The NCs were counted to confirm stability. First, 50 pmol of siRNA and each peptide (R11, RS, RT) were mixed to form NCs in a total volume of 120 μL in DPBS as described above. After 30 minutes of incubation, 20 µL of each NC was loaded in a slide (Arthur Slide; NanoEnTek, Seoul, Korea), and images were obtained using a fluorescence cell counter (Arthur™; NanoEnTek, Seoul, Korea). The number of each particle was calculated by the imaging program Image J (NIH, USA).[28]