Is it possible to track intracellular chitosan nanoparticles using magnetic nanoparticles as contrast agent?

Drug delivery systems prepared with nanostructures are able to overcome biological barriers. However, one of the main challenges in the use of these nanosystems is their internalization by macrophages. This study aims to prepare and characterize chitosan nanoparticles incorporating maghemite nanoparticles and investigate their intracellular tracking in RAW 264.7 macrophages in vitro. Then, maghemite nanoparticles were encapsulated within chitosan nanoparticles by ionotropic gelification method. The images from transmission electron microscopy were used to investigate the intracellular penetration of conjugated nanoparticles by macrophages using different times. Our data suggests that magnetic nanoparticles are suitable to act as a contrast agent to investigate the cellular internalization of chitosan nanoparticles.