Chitosan scaffold combined with recombinant human osteogenic protein-1 promotes proteoglycan synthesis of rabbit anulus fibrosus and nucleus pulposus cells

Tian Hai-quan1, Li Fang2, Ma Zhou-yong2, Chen Xiao-bin2, Wang Xiao-wei1

1Department of Orthopaedics, Second Clinical Medical College, Shanxi Medicial University, Taiyuan   030001, Shanxi Province, China; 2Military Orthopaedic Research Institute, General Hospital of Beijing Military Area Command of Chinese PLA, Beijing   100700, China

Tian Hai-quan★, Studying for master’s degree, Physician, Department of Orthopaedics, Second Clinical Medical College, Shanxi Medicial University, Taiyuan   030001, Shanxi Province, China
tianhaiquan@126. com

Correspondence to: Li Fang, Professor, Chief physician, Tutor of master, Military Orthopaedic Research Institute, General Hospital of Beijing Military Area Command of Chinese PLA, Beijing   100700, China
FANGL6722@sina. com

Received: 2008-04-10
Accepted: 2008-06-06

Abstract
BACKGROUND: Osteogenic protein-1 (OP-1) can effectively stimulate the proteoglycan and collagen synthesis by articular chondrocytes, and a single injection of OP-1 into intervertebral disc has been proved to raise the disc height in animal models.
OBJECTIVE: To in vitro determine the effect of recombinant human OP-1 (rhOP-1) on stimulating the cell proliferation and proteoglycan metabolism of rabbit intervertebral disc cells cultured in chitosan-gel.
DESIGN, TIME AND SETTING: The experiments at grouping design were carried out at the Orthopaedic Laboratory in General Hospital of Beijing Military Area Command of Chinese PLA (Beijing, China) from August 2007 to February 2008.
MATERIALS: Five Japanese rabbits of clean grade and four months old, were adopted in this study. The rhOP-1 was a product of Sigma Company (USA) in divided package. Medical chitosan, deacetylation degree 95.11%, viscosity mPa•s, Mr=870 000, was offered by Beijing Transglobal Biomedical Technology Co,. Ltd (China).
METHODS: Ten rabbit intervertebral discs were harvested, then nucleus pulposus and anulus fibrosus cells were isolated from the discs and inoculated on the self-made chitosan-gel scaffold. Culture solution was divided into three groups: control group without rhOP-1, 100 μg/L rhOP-1 group and 200 μg/L rhOP-1 group.
MAIN OUTCOME MEASURES: The synthesis and accumulation of proteoglycans (35SO42- intake and sulfate glycosaminoglycan content) and the DNA content were biochemically assessed at days 7, 14 and 21 of the culture.
RESULTS: The DNA content was unchanged in two rhOP-1 groups, while that in the control group was reduced. Treatment with rhOP-1, compared with the control condition, significantly upregulated proteoglycan synthesis and accumulation in all cases tested. A longer exposure over 14 days to rhOP-1 resulted in a pronounced response and there were significant differences between day 14 and day 21 (P < 0.001).
CONCLUSION: The rhOP-1 is effective to promote the cell proliferation and proteoglycan synthesis of rabbit anulus fibrosus and nucleus pulposus in vitro.

Tian HQ, Li F, Ma ZY, Chen XB, Wang XW.Chitosan scaffold combined with recombinant human osteogenic protein-1 promotes proteoglycan synthesis of rabbit anulus fibrosus and nucleus pulposus cells.Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu 2008;12(27):5209-5213 [www.zglckf.com/zglckf/ejournal/upfiles/08-27/27k-5209(ps).pdf]