Embodiments provide systems, methods, and compositions for nanoparticle-based drug delivery to target cells or tissues. A drug delivery system may include a nanoparticle with a targeting component and a therapeutic component. The nanoparticle may have a predetermined number or valence of targeting molecules for multivalent interaction with a target cell or tissue. Binding of the targeting molecules to the target cell may result in receptor-mediated uptake of the nanoparticle by the target cell. The therapeutic component may be subsequently released within an endocytic vesicle of the target cell. Nanoparticle-based drug delivery systems as described herein may provide improved efficacy and/or reduced toxicity.