Abstract

Demineralized bone matrix (DBM) has been regarded as an ideal bone substitute as a native carrier of bone morphogenetic proteins (BMPs) and other growth factors. However, the osteoinductive properties diverse in different DBM products. We speculate that the harvest origin further contributing to variability of BMPs contents in DBM products besides the process technology. In the study, the cortical bone of femur, tibia, humerus, and ulna from a signal donor were prepared and followed demineralizd into DBM products. Proteins in bone martix were extracted using guanidine-HCl and collagenase, respectively, and BMP-2 content was detected by sandwich enzyme-linked immunosorbent assay (ELISA). Variability of BMP-2 content was found in 4 different DBM products. By guanidine-HCl extraction, the average concentration in DBMs harvested from ulna, humerus, tibia, and femur were 0.613 ± 0.053, 0.848 ± 0.051, 3.293 ± 0.268, and 21.763 ± 0.344, respectively (p < 0.05), while using collagenase, the levels were 0.089 ± 0.004, 0.097 ± 0.004, 0.330 ± 0.012, and 1.562 ± 0.008, respectively (p < 0.05). In general, the content of BMP-2 in long bones of Lower limb was higher than that in long bones of upper limb, and GuHCl had remarkably superior extracted efficiency for BMP-2 compared to collagenase. The results suggest that the origin of cortical bones harvested to fabricate DBM products contribute to the variability of native BMP-2 content, while the protein extracted method only changes the measured values of BMP-2.

中文翻译：

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不同长骨DBM产品中BMP-2含量的差异

摘要

脱矿骨基质（DBM）作为骨形态发生蛋白（BMP）和其他生长因子的天然载体被认为是理想的骨替代品。然而，不同 DBM 产品的骨诱导特性各不相同。我们推测，除了加工技术之外，收获来源进一步导致 DBM 产品中 BMP 含量的变化。在这项研究中，制备了来自信号供体的股骨、胫骨、肱骨和尺骨的皮质骨，然后将其脱矿质制成 DBM 产品。分别用盐酸胍和胶原酶提取骨基质中的蛋白，采用夹心酶联免疫吸附法（ELISA）检测BMP-2含量。在 4 种不同的 DBM 产品中发现 BMP-2 含量存在差异。通过盐酸胍提取，从尺骨、肱骨、胫骨和股骨中收获的 DBM 的平均浓度分别为 0.613 ± 0.053、0.848 ± 0.051、3.293 ± 0.268 和 21.763 ± 0.344 (p < 0.05)，而使用胶原酶 时，水平分别为 0.089 ± 0.004、0.097 ± 0.004、0.330 ± 0.012 和 1.562 ± 0.008 ( p  < 0.05)。总体而言，下肢长骨中BMP-2的含量高于上肢长骨，GuHCl对BMP-2的提取效率明显优于胶原酶。结果表明，为制造 DBM 产品而收获的皮质骨的来源导致了天然 BMP-2 含量的变化，而蛋白质提取方法仅改变了 BMP-2 的测量值。