Why lipid nanoparticle formulations developed for biological applications should have a low polydispersity index (PDI)?

Lipid nanoparticle (LNP) formulations used in biological applications should have a low polydispersity index (PDI) since this value means that the particles in the formulation are very similar in size. Uniformity in the size of nanoparticle drugs is essential to ensure that the drug behaves consistently. This is because the size of the particles affects how they interact with the body. A PDI of less than 0.2 is generally preferred. A larger PDI indicates a nanoparticle population that is too heterogeneous and will end up showing poor transcription efficiency and repeatability.