If you mean homogenous particle dispersion in liquid phase, ultrasonic irradiation has an excellent dispersion capability for these particles with whitish color in liquid within few minutes. 35 kHz commercial cleaning ultrasonic baths is appropriate . I have already studied 1.25mg/5mL.

Thanks for you answer, Asu. 

I'm working with a rutile TiO2 nanoparticle dispersion in distilled water. After that, my goal is to study this dispersion on a biological in vitro systems.

Do you have any protocol or article that can send me? 

Thanks a lot

I use TiO2 for AOP applications in water treatment so that I don't use any dispersion  stabilizers but I had found some articles from literature about the preparation of TiO2 dispersion for biological studies such as Particle and Fibre Toxicology 2008, 5:14 and J Nanosci Nanotechnol. 2010 Aug;10(8):5213-9 which use both ultrasound and some stabilizers. Moreover, there is a protocol "Preparation of NanoscaleTiO2 Dispersions in Biological Test Media for Toxicological Assessment" published by National Institute of Standards and Technology, U.S in 2012 (NIST Special Publication 1200-4). It may be helpful for you.

I'm sure that it will help me.

thank you so much for your answer.

Dear Juliana,

you may try polyphosphate or metaphosphate.