组织工程化缓释骨形态发生蛋白2听骨赝复物听泡植入对豚鼠耳蜗功能的影响

目的 制备含缓释骨形态发生蛋白2(bone morphogenetic protein 2,BMP-2)的组织工程化听骨赝复物,植入豚鼠听泡内,观察其成骨诱导情况及对耳蜗功能的影响.方法 制备脱细胞骨微管,管腔内填塞含BMP-2胶原海绵,形成小柱状听骨赝复物.耳后人路植入豚鼠听泡,对侧耳植入不含BMP-2的赝复物作为对照.植入后不同时间点进行听性脑干反应(ABR)检测,观察听骨赝复物植入对豚鼠反应阈的影响.植入3个月后通过听泡组织切片及基底膜铺片,观察植入物成骨情况以及对听泡、耳蜗大体结构和毛细胞形态的影响.结果 术后动物健康状况良好.植入听骨赝复物即刻,ABR反应阈(声压级,x±s,下同)与术前[(15.5±2.8)dB]相比略有升高[(28.3±4.8)dB,P<0.05],3个月后已恢复正常[(16.1±4.0)dB,P>0.05].术后3个月,大体观察见植入的听骨赝复物被覆黏膜,耳蜗及听泡大体形态正常.组织学检查可见含缓释BMP-2的骨微管内壁有新骨形成,未见耳蜗及听泡骨质异常增生,镫骨底板与前庭窗周围骨质无融合.基底膜铺片硝酸银染色示毛细胞形态正常,未见缺失.结论 含缓释BMP-2的组织工程化听骨赝复物植入听泡后,可诱导新生骨形成,但对听泡及耳蜗形态结构无影响,不会引起周围骨质的异常增生,同时对ABR反应阈无影响.该方法有希望应用于听骨链缺损的修复重建.

Effect on cochlea function by tissue-engineering ossicle prothesis containing controlled release bone morphogenetic protein 2 transplanted into acoustic bulla in guinea pig

Objective To prepare the tissue-engineering ossicle prothesis which contained controlled release BMP-2 and implant into the acoustic bulla of guinea-pig, and observed the osteogenesis of the prothesis in the bulla and the effect of the prothesis on the cochlea. Methods The acellular bony microtuhule filled with collagen containing BMP-2 as tissue-engineering prothesis was implanted into the acoustic bulla of the guinea-pig through the retroauricular approach. The prothesis without BMP-2 was implanted into the contralateral bulla as control. ABR of the animals was checked after surgery at different time to observe the variation of the hearing threshold. After 3 months, the usteogenesis of the prothesis and its effect on the structure of bulla, cochlea and hair cells was observed by histological technique and silver nitrate staining method. Results The animals were recovered soon after surgery. The hearing threshold of the animals [ ( 15.5 ± 2. 8 ) dB SPL ] were increased slightly just after the surgery [ ( 28. 3 ± 4. 8 ) dB SPL, P<0.05], and come back completely after 3 month[ (16. 1 ± 4.0) dB,P >0.05]. The prothesis was covered with mucosa finally while the bulla and cochlea were normal in shape. The osteogenesis was occurred at the inner side of the acellular bony tube. There wasn't any abnormal hyperplasia of bone in the bulla and cochlea. The articulation between the stapes and oval window wasn't merged. The shape of the hair cells were normal and there wasn't obvious deletion of the hair cells compared with control group. Conclusions The tissue-engineering ossicle prothesis contained controlled release BMP-2 can induce osteogenesis in the bulla of the animals. This kind of material doesn't affect the shape of the bulla and the hearing threshold of the cochlea, moreover, they doesn't induce the abnormal hyperplasia of bone in the bulla and might be used to reconstruct the defects of ossicles.