Table 2.

Summary of the impact of each type of polydispersity for different types of nanoparticles (NP), and the relationship between impact and nanoparticle size, number of nanoparticles per aggregate and protein corona width. A single tick denotes a nanoparticle for which polydispersity has a slight (0–10%) impact on delivered dose, two ticks denotes a nanoparticle for which polydispersity has a significant (10–40%) impact on delivered dose and three ticks denotes a nanoparticle for which polydispersity has a dramatic (more than 40%) impact on delivered dose. Plus symbols (+) denote an increase in the impact of polydispersity with the corresponding parameter, whereas tilde symbols (∼) denote no change in the impact. There is no decrease in the impact of polydispersity with a parameter. ‘n.a.’ refers to a parameter that is not relevant for a particular type of polydispersity. Polymer nanoparticles refer to low-density nanoparticles (less than 3 g cm⁻³) and inorganic nanoparticles refer to high-density nanoparticles (more than 3 g cm⁻³).

	impact		size		NP/aggregate		protein corona width
polydispersity type	polymer	inorganic	polymer	inorganic	polymer	inorganic	polymer	inorganic
synthesis	✓✓	✓✓✓	+	+	n.a.	n.a.	n.a.	n.a.
aggregate	✓	✓	∼	∼	∼	∼	n.a.	n.a.
protein corona	✓	✓	∼	∼	n.a.	n.a.	+	+
size-dependent protein corona	✓✓	✓✓✓	+	+	n.a.	n.a.	+	+