Design considerations for tumour-targeted nanoparticles

• DOI: 10.1038/nnano.2009.314
• Publication Date: 2009-11-01T18:43:51Z
• Authors: Hak Soo Choi; Wenhao Liu; Fangbing Liu; Khaled Nasr; Preeti Misra; Moungi G. Bawendi; John V. Frangioni
• Keywords: Clearance

Inorganic/organic hybrid nanoparticles are potentially useful in biomedicine, but to avoid non-specific background fluorescence and long-term toxicity, they need to be cleared from the body within a reasonable timescale. Previously, we have shown that rigid spherical nanoparticles such as quantum dots can be cleared by the kidneys if they have a hydrodynamic diameter of approximately 5.5 nm and a zwitterionic surface charge. Here, we show that quantum dots functionalized with high-affinity small-molecule ligands that target tumours can also be cleared by the kidneys if their hydrodynamic diameter is less than this value, which sets an upper limit of 5-10 ligands per quantum dot for renal clearance. Animal models of prostate cancer and melanoma show receptor-specific imaging and renal clearance within 4 h post-injection. This study suggests a set of design rules for the clinical translation of targeted nanoparticles that can be eliminated through the kidneys.