A folic acid (FA)-conjugated polyamidoamine dendrimer (Den)-based nanoparticle (NP) system for co-delivery of siRNA against HuR mRNA (HuR siRNA) and cis-diamine platinum (CDDP) to folate receptor-α (FRA)-overexpressing H1299 lung cancer cells was developed. The gene discussed is ELAVL1; the disease is lung cancer.