2.2. Preparation of siRNA/peptide complexes
GAPDH-siRNA was dissolved in HBSS as 1 μM, and all peptides were
dissolved in HBSS or distilled water for 1-2 mg/mL. The sequences of all
peptides were summarized in Table 1. The fusion peptides designed in
this study have a GCG linker between SPACE and oligo arginine peptides.
Fusion peptides and siRNAs in HBSS buffer formed the self-assembled
complexes under incubation at room temperature (25°C) for 30 minutes
with appropriate nitrogen/phosphate (N/P) ratio (Fig. 1). The N/P ratio
was derived using the molar ratio of amine groups in the cationic
peptides to those of phosphate groups in the RNA.