The fusion protein RUNX1/RUNX1T1 is generated by the chromosomal translocation t(8;21) and found in 15% of all pediatric acute myeloid leukemia (AML). It causes leukaemogenic transformation by blocking differentiation and promoting self-renewal. Direct targeting using RNA interference promises a leukaemia-specific therapeutic approach, but remains associated with poor pharmacokinetic (PK) properties. This PhD-project will aim to explore lipid nanoparticles (LNP) for safe and efficacious delivery of siRNA. First, untargeted LNPs will be designed and tested and second, targeted will be designed and tested.