Mass spectrometric identification of intrinsic growth factors accumulated with Immaterial and reconstruction of highly activated bone regenerative material

将磷酸八钙（OCP）植入标准化大鼠颅骨缺损中。植入10天后，取出植入物并冻干，然后提取与植入物一起积累的蛋白质。提取的蛋白质进行纯化，并通过基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）进行测定。本研究制备了骨形态发生蛋白-2（BMP-2）复合OCP（OCP/BMP-2），并将其植入大鼠颅骨缺损区。因为OCP/BMP-2协同增强骨再生，所以OCP可用作BMP-2的有效支架（J Biomed Mater Res A 71 A：299-307，2004）。然后，我们设计了仿生骨组织成分的OCP-胶原复合物（OCP/Col），并植入。OCP/Col比单独的OCP显著增强骨再生（J Biomed Mater Res B Appl Biomater 79 B：210-217，2006），并且申请了作为“用于硬组织的替代支架”的专利。此外，我们证实了在大鼠颅骨缺损中植入OCP/Col比β-磷酸三钙胶原复合物或羟基磷灰石胶原复合物增强了更多的骨再生，这表明OCP/Col将是有效的骨再生材料（J Biomed Mater Res A in press，2007）。

Octacalcium phosphate (OCP) was implanted into the standardized rat calvarial defect. After ten days of implantation, the implants were retrieved and lyophilized, then the protein accumulated with the implants were extracted. The extracted protein was purified and was determined by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Although over 200 types of protein were detected from the experimental groups, it was difficult to identify which protein was directly involved in bone regeneration.During the process of this investigation, we prepared a composite bone morphogenetic protein-2 (BMP-2) combined with OCP (OCP/BMP-2) and implanted into the rat calvarial defect. Because OCP/BMP-2 synergistically enhanced bone regeneration, OCP may be useful as an effective scaffold for BMP-2 (J Biomed Mater Res A 71A : 299-307, 2004). Then, we have engineered OCP-collagen composite (OCP/Col) that was biomimetic components of bone tissue, and implanted. OCP/Col significantly enhanced bone regeneration than OCP alone (J Biomed Mater Res B Appl Biomater 79B : 210-217, 2006), and a patent as "Substitutional scaffold for hard tissue" was applied.. Furthermore, we confirmed that the implantation of OCP/Col in a rat cranial defect enhanced more bone regeneration than β-tricalcium phosphate collagen composite or hydroxyapatite collagen composite, suggesting that OCP/Col would be an effective bone regenerative material (J Biomed Mater Res A in press, 2007).