重组人骨形态发生蛋白2人工骨复合物在腰椎横突间植骨融合中的作用

Effect of recombinant human bone morphorgenetic protein-2 compound on lumber intervertebral fusion

背景:重组人骨形态发生蛋白2(recombinant human bon emorphorgenetic protein-2,rhBMP-2)具有较强的成骨诱导活性,但单纯BMP-2在体内易被蛋白酶所降解,其诱导活性也难以得到充分发挥。最近研究表明20%β-磷酸三钙/消旋聚乳酸(β-tricalciumphos phate/poly-(D,L-lacticacid),β-TCP/PDLLA)在结构上符合骨的生物学特点,已能达到和皮质骨相似的强度,具有良好骨传导能力,又能作为rhBMP-2的良好载体。目的:观察rhBMP-2/20%β-TCP/PDLLA复合物促进兔腰椎横突间植骨融合模型愈合的情况。设计、时间及地点:随机对照动物实验,于2006-05/2008-12在桂林医学院中心实验室完成。材料:采用浇铸盐析技术制备三维多孔20%β-TCP/PDLLA,然后与rhBMP-2复合,制成rhBMP-2/20%β-TCP/PDLLA复合物,每份复合物复合rhBMP-26mg。方法:28只新西兰兔制备L4,5横突间植骨融合模型,随机分4组:rhBMP-2/20%β-TCP/PDLLA组,20%β-TCP/PDLLA组,自体髂骨块组分别植入相应材料,空白组不植入任何材料。主要观察指标:于术后6,12周,通过大体观察、影像学、组织形态学观察,评价脊柱融合愈合情况。结果:rhBMP-2/20%β-TCP/PDLLA组及自体髂骨块组新骨形成良好,脊柱融合良好,而20%β-TCP/PDLLA组、空白组无明显的骨组织形成。结论:rhBMP-2/20%β-TCP/PDLLA复合物是一种较为理想的自体骨组织替代物,可以替代自体髂骨进行椎体间脊柱融合。

BACKGROUND： Recombinant human bone morphorgenetic protein-2 （rhBMP-2） is greatly able to induce osteogenesis; however, BMP-2 alone is easily degraded by protease, and its induction is weak. Recent research indicates that 20% β-tricalcium phosphate/poly-（D,L-lactic acid） （β-TCP/PDLLA） is ideal for biological structure, and its strength is highly closed to cortical bone; additionally, the 20% 13-TCP/PDLLA characterizes by well cranial conduction and good vector for rhBMP-2. OBJECTIVE： To evaluate the efficacy of rhBMP-2/20% β-TCP/PDLLA compound to promote healing of lumber intervertebral fusion in rabbit models. DESIGN, TIME AND SETTING： A randomized controlled animal experiment was performed at Central Laboratory of Guilin Medical College from May 2006 to December 2008. MATERIALS： Three-dimensional porous 20% β-TCP/PDLLA was prepared using casting-saRing-out technique and then composited with rhBMP-2 to obtain rhBMP-2/20% β-TCP/PDLLA compound, containing 6 mg rhBMP-2 per compound. METHODS： A total of 28 New Zealand rabbits were used to establish models of lumber intervertebral fusion; thereafter, the models were randomly divided into rhBMP-2/20% 6-TCP/PDLLA compound group, 20% 13-TCP/PDLLA group, autogenous lilac bone graft group, and blank control group. MAIN OUTCOME MEASURES： Healing of spinal fusion was evaluated using gross observation, image, and histology at 6 and 12 weeks after operation. RESULTS： Bone was well formed and spine was well fused in both rhBMP-2/20% 13-TCP/PDLLA compound group and autogenous lilac bone graft group. However, bone formation was not observed in both 20% β-TCP/PDLLA group and blank control group. CONCLUSION： rhBMP-2/20% I8-TCP/PDLLA compound is an ideal autogenous bone tissue surrogate to promote lumber intervertebral fusion.