Session I: Read-across and data completenessBack to the session
Gives a first approximation of surface charge (in buffer) which "might" give some indication of MoA - e.g. cationic particles cause membrane damage! Also, in buffer / DI water gives some indication of stability (+/- 30 mV indicates steric stabilisation and particles considered colloidally stable). But, zeta potential in media with FBS shows almost all NMs have a close to neutral but slightly negative chaarge due to protein adsorption, which also provides steric stabilisation (usually) so zeta potential in FBS-containing media is not that relevant for biological testing.
Questionable if zeta potential is predictive of toxicity. Amine and quaternized Nitrogens due lead to increased toxicity, but that does not seem to be related to their positive zeta potentials, but rather the direct attack on the cell membrane. Measuring zeta potential across several pH levels to determine the isoelectric point would confirm that the starting material is what the investigator believes it is.