人成骨细胞亲和多肽修饰多孔钽金属促进骨长入及其生物学机制的研究

In recent years, the number of revision total hip arthroplasty (RTHA) continues to grow. The patients coupled with the Paprosky Ⅲ type of bone defect in the acetabulum are the most challenging subject for RTHA. Currently, the porous tantalum metal trabecular prostheses are commonly used to perform the RTHA for the patients coupled with the Paprosky Ⅲ type of bone defect in the acetabulum. However,due to the poor contact between the prostheses and bone, the bone integration in the bone-implant interface is poor,which makes that the aseptic loosening is still the common complications.The purpose of this study is to perform the functional modification of porous tantalum metal to improve its surface compatibility, and finally strengthen the osseointegration in the bone-implant interface.In the previous study, with the method of phage display, we have screened and synthesized the osteoblast-specific affinity peptide QMLKPLE.In this subject, we attempt to further testify the affinity of QMLKPLE peptide to osteoblasts; and explore the biological mechanism of the specific affinity for QMLKPLE peptide to osteoblasts; furtherly,we attempt to construct the “functional porous tantalum metal modified by the QMLKPLE peptide”to improve the surface compatibility of the porous tantalum metal; and also, the physical and chemical properties and the capacity of recruiting osteoblasts of the “functional porous tantalum metal”were determined in vitro; finally, we attempt to use the “functional porous tantalum metal”to repair the bone defect to determine the improvement of osseointegration by the QMLKPLE peptide. Consequently,the completion of this subject could obtain the specific affinity peptide of osteoblasts, reveal the biological mechanism of this peptide to recruit osteoblasts,and could provide the experimental basis for the construction and application of functional porous tantalum metal trabecular prostheses in the RTHA coupled with the Paprosky Ⅲ type of bone defect in the acetabulum.

全髋关节翻修术（revision total hip arthroplasty，RTHA）数目持续增加，其中“髋臼侧伴有Paprosky Ⅲ型骨缺损”是RTHA的难点。目前，常用多孔钽金属材料假体行“髋臼侧伴有Paprosky Ⅲ型骨缺损”的RTHA。但是，由于“骨-假体界面”骨融合差，无菌性松动仍较常见。本研究目的是对多孔钽金属材料行“表面功能化”处理，改善钽金属的表面相容性，以加强“骨-假体界面”间骨融合。前期实验中，我们用噬菌体展示技术，筛选了“成骨细胞亲和多肽QMLKPLE”。本课题的目的是进一步验证“多肽QMLKPLE”对成骨细胞的亲和性及其生物学机制；构建功能性“QMLKPLE多肽修饰的钽金属材料”，以改善多孔钽金属材料表面相容性；并行体内外实验检测此材料促进“骨-假体界面”骨融合的效果。本课题的完成，可为“髋臼侧伴有Paprosky Ⅲ型骨缺损”的RTHA手术，提供新的思路。

全髋关节翻修术（revision total hip arthroplasty，RTHA）数目持续增加，其中“髋臼侧伴有Paprosky Ⅲ型骨缺损”是RTHA的难点。目前，常用多孔钽金属材料假体行“髋臼侧伴有Paprosky Ⅲ型骨缺损”的RTHA。但是，由于“骨-假体界面”骨融合差，无菌性松动仍较常见，导致手术失败。本研究目的是对钽金属材料行“表面功能化”处理，改善钽金属的表面相容性，以加强“骨-假体界面”间骨融合的强度。在实验中，我们首先用噬菌体展示技术，筛选了“人成骨细胞亲和多肽QMLKPLE”，并采用Fmoc固相合成法合成所筛选获得的“人成骨细胞亲和多肽QMLKPLE”。然后，使用激光共聚焦显微镜、流式细胞仪检测等方法验证“多肽QMLKPLE”对于成骨细胞的亲和能力，结果显示“多肽QMLKPLE”对于成骨细胞具有亲和力，并且无种属特异性。进而，探讨了“人成骨细胞亲和多肽QMLKPLE”作用于成骨细胞的生物学机制，研究结果显示，“人成骨细胞亲和多肽QMLKPLE”对于成骨细胞的作用机制可能与成骨细胞表面的整合素受体有关。为实现“人成骨细胞亲和多肽QMLKPLE”的转化应用，采用共价耦连的方法，将“人成骨细胞亲和多肽QMLKPLE”修饰到钽金属材料的表面，成功构建了“人成骨细胞亲和多肽QMLKPLE修饰的钽金属材料”。理化表征分析显示，“人成骨细胞亲和多肽QMLKPLE修饰的钽金属材料”较单纯的钽金属材料具有更好的亲水性，但是粗糙度无明显差异。在体外实验方面，继续使用“人成骨细胞亲和多肽QMLKPLE修饰的钽金属材料”培养成骨细胞，结果显示“人成骨细胞亲和多肽QMLKPLE修饰的钽金属材料”能在体外促进成骨细胞的粘附和伸展。在体内实验方面，进一步使用“人成骨细胞亲和多肽修饰的钽金属材料”修复新西兰大白兔股骨髁骨缺损，结果示“人成骨细胞亲和多肽QMLKPLE修饰的钽金属材料”促进“骨-假体界面”骨融合的能力优于对照组。总之，本课题的完成，可为“髋臼侧伴有Paprosky Ⅲ型骨缺损”的RTHA手术，提供新的思路。