Summary In this work, we designed replica particles based on poly(L-lysine) (PLL) polymers crosslinked via a homobifunctional linker to support coadsorption of a plasmid DNA and a peptide hormone for concurrent transfection and induction of a cellular function. PLL replica particles (PLL RP ) were prepared. Based on this PLL RP gene delivery system, we simultaneously evaluated the melanin stimulation and gene expression by fluorescence microscopy. Our data suggest that the PLL RP is a promising vector for gene therapy and hormone stimulation.