BMP及TGF-β复合生物材料治疗股骨头坏死的组织学观察

Histological observation on effects of degradable porous polymer with osteo-inducing factors in healing of femur head necrosis

目的 观察吸附有BMP 2和TGF β1的PLLA/CPPf多孔材料植入股骨头坏死 (Femurheadnecrosis ,FHN)病灶清除区后的组织学变化 ,评价其诱导成骨活性及生物降解性 ,以探索FHN治疗的新方法。方法 在激素诱导性兔FHN模型上行坏死病灶清除术 ,以该种材料充填骨腔 ,行大体和组织学光镜观察。结果 ①大体观察 ,术后 2周充填区周边出现反应带 ;6周周边反应带基本消失 ,有骨小梁长入充填区 ;12周骨小梁已布满充填区。②光镜观察 ,术后 1周充填区周围间充质细胞大量增生 ,纤维肉芽组织形成 ,开始且持续呈网状长入充填区 ;2周周边有新骨产生 ,以后不断增加并向充填区中心延伸 ,材料逐渐降解 ,12周充填区广布相对较成熟的骨小梁。结论 PLLA/CPPf多孔隙材料是生长因子的良好吸附载体 ,具有较好的生物相容性和生物可降解性 ,适合活组织长入。吸附有BMP 2和TGF β1的PLLA/CPPf多孔隙材料具有较强的诱导成骨能力 ,能有效地提高在骨坏死病理条件下股骨头的骨修复能力。

Objective To observe the histological changes after BMP-2/TGF-β 1-adsorbed PLLA(poly-L-lactic acid)/CPPf(calcium polyphosphate fiber) porous polymer being infilled into the necrotic areas of femoral heads, and evaluate their activity of osteoinduction and biodegradation in order to search a new therapy for femur head necrosis(FHN). Methods BMP-2/TGF-β 1-adsorbed PLLA/CPPf polymer was infilled into the necrotic areas of femoral heads after the nidus had been operatively cleared in glucocorticoid(GC)-inducing experimental model of femur head necrosis in rabbits. The gross and histopathologic changes were investigated in the femoral heads. Results 1) On the macrography, the reaction zone emerged around the polymer at the 2nd week. At the 6th week, the reaction zone disappeared and the bone trabecular formed and elongated into the filling areas. At the 12th week, the bone trabecular was distributed in all over the filling areas. 2) Under the microscope, a large quantity of mesenchymal cells proliferated, fibrous granulation tissue formed and began to elongate into the filling areas at the 1st week. At the 2nd week, new bone formed around the filling areas. Then its quantity continuously increased and the polymer was gradually degraded with the time passing. At the 12th week, the filling areas were full of mature trabecular. Conclusion PLLA/CPPf scaffold, as a fine carrier of growth factors, has sound biocompatibility and biodegradability in tissue growing. PLLA/CPPf-BMP-2/TGF-β1 has strong activity of osteoinduction and improves the ability of bone repair in the osteonecrotic areas of femoral heads. The therapy may become a new and effective choice of the treatment of femur head necrosis in future.