To achieve highly effective treatment to diseases, successful delivery of drugs with a carrier into
the specific organelles (nucleus, mitochondria, lysosomes, etc.) is of great importance. Targeted
delivery based on nanoparticle (NP)-based drug delivery systems (NDDSs) is mainly focused on
cell-membrane targeting. In this review we summarize researches on organelle-specific drug
delivery with multifunctional NPs. Many effective strategies are introduced for functionalizing
these NPs by altering their chemical composition or by grafting functional groups onto their
surface for improving organelle-targeting ability. Only when the concentration of released drugs
becomes high enough will they interact with molecular targets on specific organelles to induce