冻干骨的骨诱导作用

The osteoinductive properties of freeze-dried cancellous bone

目的 了解冻干骨的骨诱导特性 ,为冻干骨的应用提供依据。方法 取 4例股骨头松质骨 ,每例分成 2组。冻干照射组按骨制品制备要求处理后 ,与新鲜骨组一样 ,常规固定、脱钙 ,石蜡包埋切片 ,用免疫组织化学方法检测转化生长因子 β1(TGFβ1)和碱性成纤维细胞生长因子 (bFGF)。另用冻干骨和羟基磷灰石提取液对人骨髓间充质干细胞进行培养 ,用原位杂交方法检测细胞的碱性磷酸酶(AKP)、Ⅰ型胶原mRNA表达情况。结果 冻干照射组TGFβ1和bFGF检测阳性。但其阳性率和阳性信号要低于新鲜骨组。细胞经冻干骨提取液培养后 ,AKP、Ⅰ型胶原mRNA表达要明显高于经羟基磷灰石提取液和单纯培养液培养的细胞。结论 骨组织经冻干照射后保留了一定的有生物活性的骨诱导成分 。

Objective To understand the osteoinductive properties of freeze dried cancellous bone, and to provide the evidence for its application. Methods Each of total 4 cases of cancellous bones of femoral head was divided into two groups. After the freeze dried group was treated according to the criteria of bone bank, both of the two groups were performed fixation, decalcification, paraffin embedding, section, and assayed by immunohistochemistry of transforming growth factor β 1 (TGFβ 1)and basic fibroblast growth factor (bFGF). The in situ hybridization of alkaline phosphatase(AKP) was also performed. The human bone marrow mesenchymal stem cells were cultured with the extract of freeze dried bone and hydroxyapatite respectively, and the expression of AKP, tape Ⅰ collagen mRNA were assayed with in situ hybridization. Results The bone of freeze dried group were positive for TGFβ 1 and bFGF, but the positive site was fewer, and the positive chromogenic reaction was weaker than that of fresh bone group. The cells cultured with the extract of freeze dried bone expressed more mRNA of AKP and type I collagen than that cultured with the extract of hydroxyapatite and control medium.Conclusion After radiated, the freeze dried cancellous bone still keep some bioactive inductive elements, and possess the capability of osteoinduction.