Figure 2.
PEI-MSNs can bind and protect siRNA from cleavage by RNase-A. PEI-MSNs loaded with siRNA are treated with RNase A (Lane 4), or with heparin (Lane 5), or with RNase A followed by heparin (Lane 7), or heparin followed by RNase A (Lane 6), as described in the Experimental Section. The samples were run on a gel and visualized. Lane 1 shows gel migration of siRNA. In Lane 2, siRNA after RNase A treatment was analyzed by gel electrophoresis. siRNA bound to PEI-MSNs was retained in the gel wells and showed no sign of degradation (Lane 4). PEI-MSNs-bound siRNA was intact following incubation with RNase A and subsequent dissociation by heparin(Lane 7). siRNA dissociated from PEI-MSNs by heparinis shown in lane 5. On the other hand, siRNA that dissociated from PEI-MSNs by heparin was degraded when exposed to RNase A again (Lane 6).