Nucleic acid transfer is achieved using a silk-based delivery system which releases nucleic acids from silk-based complexes. The silk-based complexes, which are composed, for example, of plasmid DNA (pDNA) and recombinant silk containing polycation and specific polypeptides sequences, can show high biocompatibility, high delivery efficiency, cell selectivity and controlled release of nucleic acid for nucleic acid transfection.
