Zeta Potential of nanoparticles?

I have recieved questions regarding zeta potential of many different pegylated PLGA's in our catalog. Although our products can be formulated into nanoparticles (see www.polymermicelles.com) I don't have the equipment in house to analyze their zeta potential directly yet.

These polyvivo polymers will, however, be similar to other which have been reported in literature that have similar block compositions. Relative to just PLGA or PLA particles the zeta potential is reduced due to non-ionic PEG block on the surface and has been reported to be -9 to -12 for mPEG-PLA(see http://www.ff.ul.pt/FCT/PTDC/SAU-FCF/104180/2008/Dong_Y_Biomaterials.pdf) and ranging from -6 to -2.7 for mPEG-PLGA's depending on block weights (Avgoustakis, K., et al. "PLGA–mPEG nanoparticles of cisplatin: in vitro nanoparticle degradation, in vitro drug release and in vivo drug residence in blood properties." Journal of controlled release 79.1 (2002): 123-135.)(http://www.sciencedirect.com/science/article/pii/S0168365901005302)