@@An in vitro method by using microfludic chip was reported to investigate the cellular uptake of FITC-doped SiO2 nano-particles to simulate the in vivo blood flowing condition. Cell suspension was delivered from the inlet of the microchannel and immobilized onto the bottom of the channel in static conditions. The microfluidic chip containing adherent cell was placed inside an incubator (37oC and 5% CO2). Culture medium is continuously transported through the microchannel by adjusting the liquid levels of the reservoirs for 1 day (Fig.1) . After culturing the cells inside microfluidic channel, FITC-doped SiO2 particles with a diameter of 500 nm as fluorescent markers were added to the culture medium, and perfused through the microchannel via the adhered cells at different flow rates for 6 h. The effect of flow rate on the uptake efficiency of FITC-doped SiO2 particles was determined by fluorescence microscope (Fig. 2). Compared to the result (100%) in conventional cell culture flask, the uptake efficiency was significantly decreased from 74.7% to7.1%, when the flow rate increased from 0.022 to 0.74 mm/s (Fig. 3).