Passing through the renal clearance barrier: toward ultrasmall sizes with stable ligands for potential clinical applications

Abstract

Xiao-Dong Zhang,1 Jiang Yang,2 Sha-Sha Song,1 Wei Long,1 Jie Chen,1 Xiu Shen,1 Hao Wang,1 Yuan-Ming Sun,1 Pei-Xun Liu,1 Saijun Fan11Tianjin Key Laboratory of Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, People's Republic of China; 2Department of Biological Systems Engineering, University of Wisconsin-Madison, Madison, WI, USAAbstract: The use of nanoparticles holds promise for medical applications, such as X-ray imaging, photothermal therapy and radiotherapy. However, the in vivo toxicity of inorganic nanoparticles raises some concern regarding undesirable side effects which prevent their further medical application. Ultrasmall sub-5.5 nm particles can pass through the barrier for renal clearance, minimizing their toxicity. In this letter we address some recent interesting work regarding in vivo toxicity and renal clearance, and discuss the possible strategy of utilizing ultrasmall nanomaterials. We propose that small hydrodynamic sized nanoclusters can achieve both nontoxic and therapeutic clinical features.Keywords: in vivo clearance, gold nanoparticles, small size