[An experimental study of demineralized bone matrix to repair bone defects as a scaffold of tissue engineering].
OBJECTIVE
To evaluate application of the sponge of demineralized bone matrix (SDBM) in tissue engineering of bone.


METHODS
SDBM was prepared from long bone of rabbits. Bone marrow cells were flushed from the bone shaft of femurs of a two-month-old New Zealand white rabbit. After the cells were cultured for 9 days, the flasks were added into dexamethasone (10(-8) mol/L), beta-glycerophosphate sodium (10 mmol/L) and L-ascorbic acid (50 micrograms/ml). After 5 weeks, the cultured cells were collected and marked by 5-Bromo-2'-dexyouridine (BrdU). The grand sum of cells seeded on a piece of SDBM was about (4-6) x 10(6). The composites of cells and SDBM (tissue engineered chip, TEC) were implanted into muscles and bone defects of radius in rabbits. A standard procedure was applied to make a 10 mm long defect bilaterally in the radius of nine skeletally mature male New Zealand white rabbits. All of the 18 defects were randomly divided into three groups: group I, six defects were grafted by TEC; group II, six defects were grafted with SDBM alone; group III, six defects were empty.


RESULTS
The results of radiographic and histological evaluation showed that all of the defects were repaired in group I and group II at 6 weeks, none of the defects was repaired in group III. The results of BrdU staining showed that the staining was positive in group I, but negative in group II. Biomechanical test showed that the compressive ultimate strength (CUS) of new bone in TEC implanted group was comparable with normal radius (P = 0.623) and in SDBM implanted group was significant lower than normal radius (P = 0.038).


CONCLUSIONS
The TEC can form cartilage and bone tissue in muscles and repair segmental bone defects. SDBM is a kind of effective natural scaffold in tissue engineering of bone.
Sun
Ming-xue
MX
Institute of Orthopedics, PLA General Hospital, Beijing 100853, China.
Lu
Shi-bi
SB
Wang
Ji-fang
JF
Huang
Jing-xiang
JX
Yu
Zheng
Z
Zhao
Bin
B
D000818:Animals; D018775:Bone Demineralization Technique; D001854:Bone Marrow Cells / Q000166:cytology; D016026:Bone Marrow Transplantation; D001857:Bone Matrix; D020007:Implants, Experimental; D008297:Male; D011817:Rabbits; D011885:Radius Fractures / Q000601:surgery; D011897:Random Allocation; D013234:Stem Cells / Q000166:cytology; D023822:Tissue Engineering