Department of Periodontology, College of Dental Medicine, Nova Southeastern University, Fort Lauderdale, FL, USA.
Department of Cranio-Maxillofacial Surgery, Bern University Hospital, Inselspital, Bern, Switzerland.
Clin Oral Investig. 2017 Jun;21(5):1883-1893. doi: 10.1007/s00784-016-1983-0. Epub 2016 Oct 22.
Recently, recombinant human bone morphogenetic protein 9 (rhBMP9) has been characterized as one of the most osteogenic growth factors among the 15 human BMPs. The aim of the present study was to investigate the effects of rhBMP9 in comparison to the clinically utilized rhBMP2 on in vitro cell behavior when combined with two bone graft materials including demineralized freeze-dried bone allografts (DFDBAs) and biphasic calcium phosphate (BCP).
The absorption and release kinetics of rhBMPs from DFDBA and BCP were investigated by ELISA. Moreover, murine bone stromal ST2 cell behavior was investigated on DFDBA or BCP seeded on (1) graft only, (2) rhBMP2 (10 ng/ml), (3) rhBMP2 (100 ng/ml), (4) rhBMP9 (10 ng/ml), and (5) rhBMP9 (100 ng/ml). The effects of rhBMPs on DFDBA and BCP were assessed for cell adhesion, proliferation, and osteoblast differentiation by alkaline phosphatase (ALP) activity, alizarin red staining, and real-time PCR for genes encoding Runx2, ALP, and bone sialoprotein (BSP).
While both BMPs were gradually released from DFDBA and BCP over time, significantly higher adsorption was observed on BCP when compared to DFDBA. Cell attachment and proliferation was higher on BCP with little influence of either rhBMP2/9. Despite rhBMPs having relatively no effect on cell attachment/proliferation, a pronounced and marked effect was observed on osteoblast differentiation for both rhBMP2/9. Interestingly, it was observed that rhBMP9 induced significantly higher ALP activity, alizarin red staining, and messenger RNA (mRNA) levels of ALP and BSP when compared to rhBMP2. Our results also revealed higher differentiation for rhBMP2/9 with BCP when compared to DFDBA most likely as a result of higher growth factor adsorption.
While both rhBMP2/9 combined with DFDBA or BCP induced osteoblast differentiation, rhBMP9 induced greater osteoblast differentiation when compared to rhBMP2.
rhBMP9 may be a recombinant growth factor with higher potential to induce new bone formation when compared to rhBMP2. Further in vivo studies are necessary to characterize its regenerative potential in various animal models.
最近，重组人骨形态发生蛋白 9（rhBMP9）被确定为 15 种人 BMP 中最具成骨活性的生长因子之一。本研究旨在比较 rhBMP9 与临床应用的 rhBMP2 与两种骨移植材料（脱矿冻干骨同种异体移植物（DFDBA）和双相磷酸钙（BCP））联合使用时对体外细胞行为的影响。
通过 ELISA 研究 rhBMPs 从 DFDBA 和 BCP 中的吸收和释放动力学。此外，将鼠骨基质 ST2 细胞接种于 DFDBA 或 BCP 上（1）仅接种移植物，（2）rhBMP2（10ng/ml），（3）rhBMP2（100ng/ml），（4）rhBMP9（10ng/ml）和（5）rhBMP9（100ng/ml），研究 rhBMPs 对 DFDBA 和 BCP 的影响。通过碱性磷酸酶（ALP）活性、茜素红染色和实时 PCR 评估 rhBMPs 对编码 Runx2、ALP 和骨涎蛋白（BSP）的基因对 DFDBA 和 BCP 中细胞粘附、增殖和成骨分化的影响。
虽然两种 BMP 都随时间从 DFDBA 和 BCP 中逐渐释放，但与 DFDBA 相比，在 BCP 上观察到的吸附量明显更高。细胞附着和增殖在 BCP 上更高，而 rhBMP2/9 的影响很小。尽管 rhBMPs 对细胞附着/增殖几乎没有影响，但对成骨分化有明显而显著的影响。有趣的是，与 rhBMP2 相比，rhBMP9 诱导的 ALP 活性、茜素红染色和 ALP 和 BSP 的信使 RNA（mRNA）水平更高。我们的结果还表明，rhBMP2/9 与 BCP 结合时，与 DFDBA 相比，分化程度更高，这可能是由于生长因子的吸附量更高。
rhBMP2/9 联合 DFDBA 或 BCP 均可诱导成骨分化，但 rhBMP9 诱导的成骨分化比 rhBMP2 更强。
rhBMP9 可能是一种具有更高诱导新骨形成潜力的重组生长因子。需要进一步的体内研究来表征其在各种动物模型中的再生潜力。
