Objective        To investigate how to culture and identify rabbit adipose-derived stem cells (ADSCs)

and to explore the feasibility of tracing ADSCs after being labeled by superparamagnetic iron oxide particles (SPIO) combined with poly-l-lysine (PLL) in vitro.       Methods        ADSCs were isolated from New Zealand rabbit

and then purified and primarily cultured. Flow cytometry (FCM) was used to identify cell surface antigens CD44

CD90 and CD34. Transmission electron microscopy (TEM) was used to observe the intracellular iron particles in SPIO-PLL labeled ADSCs after Prussian blue staining. 3.0-T MR scanning in vitro system was used to scan 1×10

7

ADSCs unlabeled and labeled with 25

50 and 75 μg/mL SPIO-PLL respectively

or labeled with 25 μg/mL for 1 or 3 d

or to scan 5×10

6

cells labeled with 25 μg/mL for 1 d. T

1

WI

T

2

WI and T

*

2

WI arrays were performed for the signal intensity (SI) and relaxation time of each tube.       Results        The ADSCs of third generation were of high purity

in regular arrangement presenting whirlpool-like. The cells had an expression rate of 98.7% for CD44 and 99.2% for CD90

but negative expression for CD34. TEM showed that iron particles existed in the cytoplasm of ADSCs after Prussian blue staining

and the rate of labeling was nearly 100%. T

*

2

WI and T

2

WI demonstrated a more obvious decrease in SI than that of T

1

WI with the increasing concentration of SPIO-PLL. The percentage of SI in 1×10

7

ADSCs (labeled for 1 d) was significantly higher than that of 1×10

7

(labeled for 3 d) and 5×10

6

(labeled for 1 d). The relaxation time of T

*

2

and T

2

compared with T

1

was significant different (F=161.47

P

0.05)

but the relaxation time between T

*

2

and T

2

was not statistically significant (F=5.88

P

0.05).       Conclusion        Sufficient ADSCs are obtained th

rough isolation

purification and culture. ADSCs are labeled effectively by SPIO-PLL and detected through MR scanning in vitro

with T

*

2

WI and T

2

WI arrays more sensitive.