What is the ideal size for a nanocarrier?

The ideal nanocarrier size depends on the application and the required drug loading. Typically, nanocarriers should be smaller than 400 nm to prevent mononuclear phagocytes from being recognized and cleared by the immune system. Nanocarrier size affects in vivo distribution, with smaller particles having lower liver uptake. For most of these applications, the nanocarrier should be smaller than 200 nm, ideally ≤100 nm, to improve the permeability and retention (EPR) effect and thus extravasation of the drug into the tumor. If the size is <100nm, there are reports of higher rates of drug entry into cells and faster lymphatic transport. It should be noted that as the size decreases, the loading capacity also decreases, so more NP may be required to ensure the therapeutic effect. In addition to nanocarrier size, its composition, shape, and surface charge can also influence release behavior and accumulation.