Figure 1.

A) Size distribution of chitosan/HA nanoparticles (1 mg/mL, deionized water) prepared from 35 (top) and 650 (bottom) kDa chitosan using a templated (dashed lines) or direct (solid lines) complexation in the absence (left) or presence (right) of siRNA (25 wt % in relation to chitosan). In this and later figures Chit₃₅ and Chit₆₅₀ are, respectively, referred to as low-M_W and high-M_W chitosan to avoid the use of subscripts for a better readability. B) Quantification of free HA after nanoparticle preparation. Left: The HA content of the different nanoparticle formulations (1 mg/mL, deionized water) was measured by capillary electrophoresis before and after dialysis (MWCO = 1,000 kDa). Results are expressed as the relative amount of complexed HA (incorporated in the nanoparticle) relative to the total amount of HA in the nanoparticle feed (n = 3). Right: AFM amplitude images of (low-M_W chitosan) nanoparticles after dialysis showing the complete removal of unbound HA (absence of “debris” material on the mica surface).