Taken together, the tyrosine-modified LP10Y lipopolyplex and the PPI-Y dendriplex show particularly promising profiles as delivery platforms for RNAi (e.g., siRNA, miRNA), characterized by high gene knockdown efficacy, deep tissue penetration, and high biocompatibility in both SH-SY5Y neuroblastoma cells overexpressing wild-type aSyn56 and the Thy1-aSyn mouse model of PD. The gene discussed is THY1; the disease is neuroblastoma.