胶原复合梯度TCP修复关节软骨的形态学观察

目的采用新型双向三维可降解生物活性材料胶原复合梯度TCP（collagen complexTCP，Col／TCP）对兔关节软骨缺损进行修复，并对再生软骨进行组织形态学观察。方法取30只成年大白兔，体重2．0～2．5kg，雌雄不限，于双侧股骨外侧髁制作关节软骨缺损模型。于右侧植入Col／TCP修复缺损，作为实验组，左侧不予处理作为对照组。术后4、6、8、12和24周分别处死6只动物，取股骨外侧髁关节面行大体、组织学、透射电镜及Ⅱ型胶原免疫组织化学染色观察。采用Wakitanifa法软骨组织形态学评分评价修复组织质量。结果大体观察：实验组术后4周，缺损区由白色组织完全充填，表面较光滑，有光泽；12周，修复关节软骨组织与周围正常软骨基本一致，且与关节下骨结合紧密；24周，再生软骨未见明显退变。对照组观察期内均未见软骨组织形成，缺损由纤维组织填充，修复组织表面粗糙，与正常组织界线清楚。实验组术后4、6、8、12和24周组织学评分分别为（7．60±0．98）、（5．69±0．58）、（4．46±0．85）、（4．35±0．12）、（4．41±0．58）分，对照组分别为（10．25±1．05）、（9．04±0．96）、（8．96±0．88）、（8．88±0．68）、（8．66±0．54）分；Ⅱ型胶原含量实验组分别为0．28％±0．01％、0．59％±0．03％、0．68％±0．02％、0．89％±0．02％和0．90％±0．01％，对照组为0．08％±0．02％、0、09％±0．04％、0．11％±0．03％、0．25％±0．03％和0．29％±0．01％；两组各指标比较差异均有统计学意义（P〈0．05）。透射电镜观察实验组可见典型软骨细胞，而对照组为粗大胶原纤维，细胞少见。结论双向三维可降解生物活性材料Col／TCP在动物体内可诱导关节软骨缺损后的软骨修复。

MORPHOLOGICAL OBSERVATION ON REPAIRING ARTICULAR CARTILAGE DEFECTS WITH COLLAGEN COMPLEX GRADIENT TCP

OBJECTIVE: To repair the defects in articular cartilage with collagen complex gradient TCP in vivo and to study the regenerated cartilage histomorphologically. METHODS: The models of defects in articular cartilage were made artificially in both condylus lateralis femoris of mature rabbits, male or female, with the weight of 2.0-2.5 kg. The right defects were implanted with the material of Col/TCP as the experimental group and the left defects were untreated as the control group. The rabbits were killed at 4, 6, 8, 12 and 24 weeks after operation, respectively, with 6 ones at each time, and the macroscopic, histological, ultrastructural examinations and semi-quantity cartilage scoring employing Wakitanifa repaired cartilage value system were performed. RESULTS: Four weeks after operation, the defects in the experimental group were partly filled with hyaline cartilage. Twelve weeks after operation, the defects in the experimental group were completely filled with mature hyaline cartilage. Twenty-four weeks after operation, regenerated cartilage had no cataplasia. However, fibrous tissues were seen in the control group all the time. At 4, 6, 8, 12 and 24 weeks postoperatively, the Wakitanifa cartilage scores were 7.60 +/- 0.98, 5.69 +/- 0.58, 4.46 +/- 0.85, 4.35 +/- 0.12 and 4.41 +/- 0.58, respectively, in the experimental group and 10.25 +/- 1.05, 9.04 +/- 0.96, 8.96 +/- 0.88, 8.88 +/- 0.68 and 8.66 +/- 0.54, respectively, in the control group. At 4, 6, 8, 12 and 24 weeks postoperatively, the collagen II contents were 0.28% +/- 0.01%, 0.59% +/- 0.03%, 0.68% +/- 0.02%, 0.89% +/- 0.02% and 0.90% +/- 0.01%, respectively, in the experimental group, while 0.08% +/- 0.02%, 0.09% +/- 0.04%, 0.11% +/- 0.03%, 0.25% +/- 0.03% and 0.29% +/- 0.01%, respectively, in the control group. Differences between the control group and the experimental group were significant (P < 0.05). By then, typical chondrocyte was observed by transmission electron microscope in the experimental group and much fiber with less fibrocyte was observed in the control group. CONCLUSION: Three-dimensional scaffold collagen complex gradient TCP may induce cartilage regeneration to repair the defects of articular cartilage in vivo.