The Johns Hopkins Applied Physics Laboratory 1 article published in JoVE Bioengineering Solid Lipid Nanoparticles (SLNs) for Intracellular Targeting Applications Xiomara Calderón-Colón1, Giorgio Raimondi2, Jason J. Benkoski1, Julia B. Patrone3 1Research and Exploratory Development Department, The Johns Hopkins Applied Physics Laboratory, 2Department of Plastic and Reconstructive Surgery, Johns Hopkins School of Medicine, 3Asymmetric Operations Sector, The Johns Hopkins Applied Physics Laboratory In this study, a method for synthesizing ultra-small populations of biocompatible nanoparticles was described, as well as several in vitro methods by which to assess their cellular interactions.