Biocompatibility studies of fluorescent diamond particles-(NV)∼800nm (part V): in vitro kinetics and in vivo localization in rat liver following long-term exposure

Jonathan A Gerstenhaber,1,* Cezary Marcinkiewicz,1,2,* Frank C Barone,3 Mark Sternberg,2 Michael R D’Andrea,4 Peter I Lelkes,1 Giora Z Feuerstein21Department of Bioengineering, College of Engineering, Temple University, Philadelphia, PA, USA; 2Debina Diagnostic Inc., Newtown Square, PA, USA; 3SUNY Downstate Medical Center, Department of Neurology, Brooklyn, NY, USA; 4Analytical Biological Services Inc., Wilmington, DE, USA*These authors contributed equally to this workBackground: We recently reported on long-term comprehensive biocompatibility and biodistribution study of fluorescent nanodiamond particles (NV)-Z-average 800nm (FNDP-(NV)) in rats. FNDP-(NV) primary deposition was found in the liver, yet liver function tests remained normal.Purpose: The present study aimed to gain preliminary insights on discrete localization of FNDP-(NV) in liver cells of the hepatic lobule unit and venous micro-vasculature. Kinetics of FDNP-(NV) uptake into liver cells surrogates in culture was conducted along with cell cytokinesis as markers of cells’ viability.Methods: Preserved liver specimens from a pilot consisting of two animals which were stained for cytoskeletal elements (fluorescein-isothiocyanate-phalloidin) were examined for distribution of FNDP-(NV) by fluorescent microscopy (FM) and Confocal-FM (CFM) using near infra-red fluorescence (NIR). Hepatocellular carcinoma cells (HepG-2) and human umbilical vein endothelial cells (HUVEC) were cultured with FNDP-(NV) and assayed for particle uptake and location using spectrophotometric technology and microscopy.Results: HepG-2 and HUVEC displayed rapid (