[A preliminary study of high viscous chitosan/glycerol phosphate with demineralized bone matrix to repair cartilage defects in rabbits].
OBJECTIVE
To evaluate the effect of implantation of the complex of high viscous chitosan/glycerol phosphate with demineralized bone matrix (HV-C/GP-DBM) in repairing cartilage defects of rabbits.


METHODS
HV-C/GP-DBM was prepared by compounding HV-C/GP and DBM by 2:1 (W/W). Twenty-four 34-week-old New Zealand white adult rabbits, weighing 3.5-4.5 kg, were included. A bit with the diameter of 3.5 mm was used to drill 3-cm-deep holes in both sides of femoral condyle to make cartilage defects. The complex of HV-C/GP-DBM was then injected into the right holes as the experimental group and the left ones serve as the control group. The rabbits were killed at 4, 8 and 16 weeks after the operation, respectively. The obtained specimens were observed macroscopically, microscopically and histologically. According to the International Cartilage Repair Society Histological Scoring (ICRS), the effect of cartilage repair was assessed at 16 weeks postoperatively.


RESULTS
At 4-8 weeks postoperatively, in the experimental group, the defects were filled with hyaline cartilage-like tissues; the majority of chitosan degradated; and the DBM particles were partly absorbed. However, in the control group, there were small quantities of discontinuous fibrous tissues and maldistributed chondrocytes at the border and the bottom of the defects. At 16 weeks postoperatively, 6 joints in the experimental group had smooth surface, and the defects were basically repaired by hyaline cartilage-like tissues. The newly-formed tissues integrated well with the surrounding area. Under the cartilage, the new bone formation was still active and some DBM particles could be seen. However, the defects in the control group were repaired by fibrous tissues. The result of histological scoring of the specimens at 16 weeks showed that a total of 6 aspects including formation of chondrocytes and integration with the surrounding cartilages were superior in the experimental group to those in the control group, and there were significant differences between the two groups (P < 0.05).


CONCLUSIONS
The biodegradable and injectable complex of HV-C/GP-DBM with good histocompatibility and non-toxic side effects can repair cartilage defects and is a promising biomaterial for cartilage defect repair.
Jing
Bo
B
Department of Orthopaedics, First Municipal Hospital of Handan, Handan Hebei 056002, PR China. Jumbojing2006@gmail.com
Wang
Zhiqiang
Z
Li
Baoxing
B
Cheng
Zhishan
Z
Kang
Yue
Y
Li
Qijia
Q
D000818:Animals; D001672:Biocompatible Materials; D018775:Bone Demineralization Technique; D001857:Bone Matrix / Q000637:transplantation; D002356:Cartilage / Q000473:pathology / Q000601:surgery; D002357:Cartilage Diseases / Q000601:surgery*; D017690:Cell Transplantation; D002478:Cells, Cultured; D048271:Chitosan / Q000627:therapeutic use*; D005990:Glycerol / Q000627:therapeutic use*; D048091:Guided Tissue Regeneration; D011817:Rabbits; D023822:Tissue Engineering; D014945:Wound Healing
D001672:Biocompatible Materials; D048271:Chitosan; D005990:Glycerol