OBJECTIVE: To explore the survival time of autogeneic BMSCs labeled by superparamagnetic iron oxide (SPIO) in rabbit intervertebral discs and the rule of migration so as to prove bases of gene therapy preventing intervertebral disc degeneration. METHODS: Twelve rabbits were used in this experiment, aged 8-10 weeks, weighing 1.5-2.0 kg and neglecting their gender. BMSCs were separated from rabbits bone marrow by density gradient centrifugation and cultivated, and the 3rd generation of BMSCs were harvested and labeled with SPIO, which was mixed with poly-l-lysine. The labeling efficiency was evaluated by Prussian blue staining and transmission electron microscope. Trypanblau stain and MTT were performed to calculate the cell's activity. Rabbits were randomly divided into experimental group (n = 8) and control group (n = 4), the labeled BMSCs and non-labeled BMSCs (5 x 10(5)/mL) were injected into their own intervertebral discs (L1,2, L2,3, L3,4 and L4,5), respectively. At 2, 4, 6 and 8 weeks, the discs were treated with Perl's fluid to observe cell survival and distribution. RESULTS: The labeling efficiency of BMSCs with SPIO was 95.65% +/- 1.06%, the cell activity was 98.28% +/- 0.85%. There was no statistically significant difference in cell proliferation within 7 days between non-labeled and labeled cells (P > 0.05). After 8 weeks of operation, the injected cells was alive. CONCLUSION: Labeled BMSCs with SPIO is feasible in vitro and in vivo, and the cells can survive more than 8 weeks in rabbit discs.
OBJECTIVE: To explore the survival time of autogeneic BMSCs labeled by superparamagnetic iron oxide (SPIO) in rabbit intervertebral discs and the rule of migration so as to prove bases of gene therapy preventing intervertebral disc degeneration. METHODS: Twelve rabbits were used in this experiment, aged 8-10 weeks, weighing 1.5-2.0 kg and neglecting their gender. BMSCs were separated from rabbits bone marrow by density gradient centrifugation and cultivated, and the 3rd generation of BMSCs were harvested and labeled with SPIO, which was mixed with poly-l-lysine. The labeling efficiency was evaluated by Prussian blue staining and transmission electron microscope. Trypanblau stain and MTT were performed to calculate the cell's activity. Rabbits were randomly divided into experimental group (n = 8) and control group (n = 4), the labeled BMSCs and non-labeled BMSCs (5 x 10(5)/mL) were injected into their own intervertebral discs (L1,2, L2,3, L3,4 and L4,5), respectively. At 2, 4, 6 and 8 weeks, the discs were treated with Perl's fluid to observe cell survival and distribution. RESULTS: The labeling efficiency of BMSCs with SPIO was 95.65% +/- 1.06%, the cell activity was 98.28% +/- 0.85%. There was no statistically significant difference in cell proliferation within 7 days between non-labeled and labeled cells (P > 0.05). After 8 weeks of operation, the injected cells was alive. CONCLUSION: Labeled BMSCs with SPIO is feasible in vitro and in vivo, and the cells can survive more than 8 weeks in rabbit discs.