Biodistribution studies of protein cage nanoparticles demonstrate broad tissue distribution and rapid clearance in vivo

Coleen R Kaiser¹, Michelle L Flenniken^2,3, Eric Gillitzer^3,4, Ann L Harmsen¹, Allen G Harmsen¹, Mark A Jutila¹, Trevor Douglas^3,5, Mark J Young^3,4

¹Department of Veterinary Molecular Biology; ²Department of Microbiology; ³Center for Bio-Inspired Nanomaterials; ⁴Department of Plant Sciences; and ⁵Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana, USA

Abstract: Protein cage nanoparticles have the potential to serve as multifunctional cell targeted, imaging and therapeutic platforms for broad applications in medicine. However, before they find applications in medicine, their biocompatibility in vivo needs to be demonstrated. We provide here baseline biodistribution information of two different spherical protein cage nanoplatforms, the 28 nm viral Cowpea chlorotic mottle virus (CCMV) and the 12 nm heat shock protein (Hsp) cage. In naïve and immunized mice both nanoplatforms show similar broad distribution and movement throughout most tissues and organs, rapid excretion, the absence of long term persistence within mice tissue and organs, and no overt toxicity after a single injection. These results suggest that protein cage based nanoparticles may serve as safe, biocompatible, nanoplatforms for applications in medicine.

Keywords: protein cage nanoparticles, Cowpea chlorotic mottle virus, heat shock protein, biodistribution