Metal complexes, as a type of potential non-virus gene carriers, have gained much attention due to their properties of high charge density and unique three-dimensional structure. This study investigated the potential of polyethyleneimine (PEI)-modified rice bran polysaccharide-Fe(III) complex (PEI-PI) as a safe gene delivery system and explored the effect of Fe(III) on the efficiency of gene transfection mediated by PEI modified rice bran polysaccharide (PEI-P) and PEI-PI. Gel retardation assay was used to study the DNA binding and protection capability, MTT assay was performed to evaluate the...