山羊胫骨大段骨缺损的组织工程骨修复及放射性核素显像监测

Repair of tibial defect with tissue-enigineered bone graft and radionuclide bone imaging in goats

目的探讨组织工程骨对山羊大段骨缺损的修复能力及放射性核素骨显像技术在此过程中的监测效果。方法将27只中国青山羊,分为组织工程骨组、人工骨组和对照组(每组9只)并分别造成左侧胫骨2cm骨缺损。对组织工程骨组缺损区植入珊瑚羟基磷灰石(CHAP)和骨髓基质干细胞(BMSc)复合体,人工骨组植入CHAP,对照组则不植入任何填充物。采用放射性核素骨显像于术后2、4、8周监测各组骨修复情况。结果通过放射性核素骨显像测定的感兴趣区(ROI)计数和T/NT比值显示:对照组在各时间点均未见再血管化的表现及明显的成骨活动;人工骨组随着时间的延长其血管再生的数量和成骨的质量呈现出上升的趋势;组织工程骨组上升趋势更为显著。结论组织工程骨较人工骨具有更佳的修复大动物大段骨缺损的能力,放射性核素骨显像在修复过程中有比较准确的预测效果。

Objective To observe the effect o f tissue-engineered bone grafts in repairing large tibial defect in goats, and ass ess the value of radionuclide bone imaging in monitoring the therapeutic effect of this approach. Methods Tibial defects measur-ing 2 cm was artificially made in the left tibia of 27 normal goats that were subsequently divided into 3 group s (9 each) to un-dergo treatment with tissue-engineered bone grafts, artificial bone grafts or without any grafts (as control group) respectively. The tissue-engineered bone grafts contained bone marrow stroma cells (BMSCs) of th e goats and coral hydroxyapatite (CHAP), while the artificial bone grafts we re from CHAP only. After the operations, radionuclide bone imaging was used to monitor the therapeutic effects at 2, 4 and 8 postoperative weeks. Results The 99 mTc-MDP uptake of the region of interest (ROI) and the target to non-target ratios (T/NT) of the control group did not indicate any process of revasculariza tion or bone regeneration. An increasing tendency of the revascularization and bone regeneration, in contrast, was observed in goats receiv-ing the artificial bone grafts, a tendency that was far more obvious in the goats with tissue-engin eered bone grafts. Conclusion Tissue-engineered bone graft is eligible in repair ing large defect in the caprine tibia, and radionuclide bone imaging may accu-ra tely monitor the revascularization and bone regeneration after the bone graft im plantation.