In this paper, results concerning the dispersion by different ways of a very common industrial titania NP (Degussa P25 produced in ton quantities). When dispersed in water, the suspensions of NP appear stable for weeks. When transferred in the cell culture medium (DMEM) or if directly dispersed in DMEM, strong evolution of size is seen as well as sedimentation. To address this problem and avoid direct aggregation, when going to DMEM, a "surfactant" relevant with biological studies (FBS) prior to transfer in DMEM (or other cell media) can be used. The main results are presented here.