Well, a major challenge is the liver, because the liver is the body's filtration system, and the liver recognizes and destroys foreign objects, such as viruses, bacteria and also nanoparticles.
Tantangan terbesar adalah hati, karena hati adalah sistem penyaringan tubuh, hati mengenali dan menghancurkan objek asing, seperti virus, bakteri, dan nanopartikel.