Figure 10. Superior transport and neuroprotective activity of nanozyme loaded in macrophages compared to cell-free nanozyme.

(A) Effect of nanozyme loading into human macrophages on its accumulation in HBMEC: the recipient cells were incubated with cell free nanozyme or exposed to macrophages loaded with fluorescently-labeled nanozyme for four hours. Following incubation, the cells were collected and the amount of nanozyme accumulated in HBMEC was determined by FACS. (B) Effect of nanozyme loading into murine macrophages on its neuroprotective activity in in vitro PD model: CATH.A neurons were incubated with 6-OHDA in the presence of murine macrophages loaded with nanozyme or the same amount of free nanozyme for four hours. Following incubation, the cells were washed, stained with LIVE/DEAD dye and neuronal survival accessed by FACS. Data are expressed as % of control cells cultured in the media. To distinguish between the carrier cells and target cells, human and murine macrophages were labeled with Alexa 678-conjugated Ab to CD 14 and CD 11b, respectively, prior to the addition. Results from N=4 wells (± SEM) clearly demonstrated that transport to HBMEC (A), and neuroprotective activity (B) of nanozyme from the cell-carriers, were substantially greater, compared to the transport and activity of free nanozyme.