Luminescent gold nanoparticles with efficient renal clearance.

Abstract

Developing functional nanomaterials with efficient renal clearance is of fundamental importance to their in vivo biomedical applications.[1] Ideal nanomaterial based contrast agents should be effectively cleared out of the body, have little accumulation in organs and show minimum interference with other diagnostic tests.[1c, 1e, 2] While significant progress has been made toward the creation of fluorescent quantum dots with efficient renal clearance,[2] in vivo applications of noble metal nanoparticles (NPs), another promising nanomedicine in biomedical imaging, drug delivery, antibacterial and photothermal therapy,[3] are still severely hampered by their slow renal clearance and high nonspecific accumulations in the reticuloendothelial system (RES) organs (e.g. liver, spleen) after systematic administration.[4] Although NPs with hydrodynamic diameter (HD) smaller than 10 nm are generally considered being stealthy to the RES organs, they are still often found in the liver.[2a] For example, nearly ~50% of 1.4 nm gold NPs (AuNPs) were found in the liver and only ~9% of them can be excreted into urine in 24 hours after intravenous (IV) injection.[4b] Therefore, developing metal NPs with efficient renal clearance and fundamental understanding of key factors in renal clearance are highly desirable.