Visualization of hybrid gold-loaded polymeric nanoparticles in cells using scanning electron microscopy

Nanotechnology is growing quickly, with great advances in the area of nanomedicine. Opening the door to personalized medicine, a considerable number of nanosystems have been synthetized for the diagnosis, treatment and monitoring of diseases. Specifically, gold nanoparticles (AuNPs) have been shown to be good contrast agents. However, they have a limited surface area for the transport of active molecules. In this paper, polymeric nanoparticles encapsulating AuNPs have been synthetized by the double emulsion method (w/o/w) and solvent evaporation technique. This approach opens up the possibility of encapsulating hydrophilic and/or lipophilic thermostable biomolecules. The nanoparticles could be monitored in macrophage cells by simple scanning electron microscopy (SEM). Nevertheless, a micro computed tomography (micro-CT) study revealed that they would not be detected in future in vivo studies. In short, this paper explains the difficulty of obtaining nanovehicles that are trackable from early investigation stages to their clinical use, and discusses the controversy surrounding the concentration of AuNPs needed to obtain enough X-ray attenuation with safe doses. (C) 2017 Elsevier B.V. All rights reserved.