 Polymer nanoparticles, N-piece, are a promising approach for drug delivery applications due to their biocompatibility and ability to target specific organs or tissues. They can be made from a variety of biocompatible synthetic polymers such as polylactic acid, PLA, polylactic co-glycolic acid, PLGA, and polyethylene glycol, PG. These polymers are composed of simple monomers that are already present in the body and thus easily excreted without causing any harm. Different loading methods have been developed to incorporate therapeutic agents into these polymer N-piece, including physical dispersion and encapsulation within the polymer matrix. Additionally, polymer N-piece can be designed to target specific cells or cross cellular membranes, making them ideal for treating diseases like cancer. This article was authored by Eleonora Calzoni, Alessio Cesarelli, Alice Polci, and others.