Compositions for siRNA delivery are described which include water soluble degradable crosslinked cationic polymers having a water soluble polyethylene glycol component, a cationic polyethyleneimine component and a degradable unit component. The composition may be used to deliver siRNA to cells, particularly cancer cells. The composition may be applied to a solid surface such as a multiwell plate so that the delivery of siRNA may be carried out on the solid surface.
