Paclitaxel-Primed Mesenchymal Stem Cells

SR4987 and hMSCs (3×10⁵) were treated 24 hours with PTX (2.000 ng/ml) (Serva, Germany). At the end of the incubation, the cells were washed twice with PBS, then trypsinized, washed twice in HBSS and seeded in a new flask. After 24 h of culture, the cell conditioned medium (CM) was collected and replaced by repeating this procedure at 48, 72, 96 and 144 hours. The CM were tested for their anti-tumor proliferation activity in vitro by using CM from untreated MSCs as negative controls. The passive membrane drug adsorption and release by fixed cells were also verified. The internalisation of PTX into MSCs was checked by Fluorescent PTX (Oregon Green 488 Taxol, Invitrogen, UK). The effect of 24 h drug treatment on the cell cycle of MSCs was evaluated by FACS. The presence of PTX in the CM of primed MSCs was confirmed by HPLC [51] (link) (see supporting information Text S1).