Fig. 2.

PF14 induces knock-down of an endogenous gene with a unique kinetic profile. A. Dose–response curves for the down-regulation of HPRT1 by PF14/siRNA nanocomplexes in HUH7 cells in serum-containing medium (solid line) and in serum-free medium (dotted line). The concentration at which 50% of HPRT1 mRNA was depleted (EC₅₀) was 12 nM and 8 nM for the serum and serum-free conditions respectively. B. Comparison between the efficiency of one selected dose (50 nM) of siRNA transfected by PF14 or by LF RNAimax® or naked siRNA without any transfection reagent. Control siRNA of unrelated sequence at the same concentration transfected with PF14 was also included. C and D: Kinetics of the HPRT1 down-regulation using a 50 nM dose of siRNA transfected with PF14 at serum-containing and serum-free conditions and with LF RNAimax®. C. represents the kinetics up to 24 h while D. shows the time-course study as monitored up to 4 days. Significant differences were detected in the % of HPRT1 mRNA remaining after 2 h using PF14 (in serum free) and LF RNAimax® (P < 0.001) and after 4 h (P < 0.01). Significant difference was seen as well between treatment with PF14 (in serum) and LF RNAimax® after 2 h (P < 0.05).