To identify whether posttransplantation symptom improvement is induced by the transplantation, invasive method is traditionally used, but this method is not suitable for dynamic tracing or human study. Under the help of suitable tracer, noninvasive imaging technique for in vivo identification and for tracing cell survival following transplantation can significantly elevate academic value of the cell transplantation therapy.OBJECTIVE:
To primarily explore the feasibility of protocols using Feridex-polylysine compound for in vivo magnetic labeling of rabbit bone marrow stromal cells (BMSCs).DESIGN, TIME AND SETTING:
The cytological in vitro observation was performed at the Laboratory of the Department of Neurosurgery, Zhujiang Hospital from March to August 2008.MATERIALS:
Eight New Zealand rabbits aged 2 months were supplied by the Experimental Animal Center, Guangzhou University of Chinese Medicine. Feridex (Advanced Magnetic) and polylysine (Sigma, USA) were used for this study.METHODS:
Under the sterile condition, the rabbit bone marrow stromal cells were harvested from rabbit femur by density gradient centrifugation following a thighbone puncture. At the second passage, cells were collected and incubated in neural stem cell medium containing leukaemia inhibitory factor, basic fibroblast growth factor and fetal bovine serum for 5 days. 50 mg/L Feridex was mixed with 1.5 mg/L polylysine for 30 minutes of shaking. The compound was added into cell medium for labeling, and incubated with cells for 24 hours.MAIN OUTCOME MEASURES:
The following parameters were measured: differentiation of BMSCs into neural stem cells; determination of iron in cells; effects of Feridex-polylysine compound labeling for cell proliferation or differentiation.RESULTS:
Following induction, the bodies of some BMSCs became round and big, with short processes. With time prolonged, round cells gradually increased, and some gathered in cluster. FITC fluorescence staining showed BMSCs were positive for nestin. Prussian blue staining showed numerous blue stained fine particles in the cytoplasm of 99% BMSCs. BMSCs in Feridex-polylysine compound medium could proliferate and differentiate, but number of iron particles decreased in cytoplasm following proliferation, and some were positive for neuron specific enolase.CONCLUSION:
Feridex-polylysine compound may be used to effectively label BMSCs in vitro, and cell viability, proliferation and differentiation ability is not affected.