Fig. 6

Au NP uptake capacity is donor dependent. MSCs in 3rd or 4th passage were labeled with 10 nM Au NPs for 48 h in vitro. Internalized Au NPs were measured by ICP-MS, revealing considerable variations of Au NP uptake between eleven different MSC donors. Experiments were performed independent to preceding measurements. A different batch of Au NPs was used, which was purified by ultracentrifugation instead by gel electrophoresis. Thus, absolute Au NP content as compared to Fig. 1 may vary