具有骨诱导活性的仿生骨基质材料的制备

Preparation and characterization of oligopeptide modified PLGA-[ASP-PEG]biomimetic scaffolds

目的将一种具有与骨形态发生蛋白2相似骨诱导活性的多肽p24共价结合于改性聚(丙交酯-co-乙交酯)基质材料上,以制备出具有骨诱导活性的仿生骨基质材料。方法将活性多肽p24通过交联剂共价结合于改性PLGA材料上作为实验组；以未加交联剂多肽溶液和材料简单混合反应为对照组,通过X射线光电子光谱法和扫描电镜检测交联情况；同时对两组材料进行钙离子吸附实验,初步评价其仿生矿化能力。结果XPS检测结果表明,实验组及对照组材料表面均已结合硫元素,两者含有硫元素含量分别为1.50%及0.09%；钙离子吸附实验结果表明,12h及24 h时实验组材料的钙离子吸附量分别为0.126mg及0.231mg；12h及24h时对照组材料的钙离子吸附量分别为0.053、0102mg。多肽交联之材料较混合之材料的钙离子吸附能力显著增强。结论在改性PLGA三嵌段材料上固定了BMP2活性多肽,为以后发挥其骨诱导活性修复骨缺损奠定了良好基础。

Objective To prepare a new biomimetic bone matrix material for tissue engineering by integrating polypeptide, which has excellent osteoinduction, with modified PLGA scaffold using crosslinkers. Methods The BMP-2-derived peptide was devised and synthetized, and PLGA-[ASP-PEG] was modified with polypeptide by methods of physical entrapment and chemical coupling, using 1-ethyl- 3-（3- dimethylaminopropyl） carbodiimide （EDC） and N-hydroxysuccinimide （NHS） as cross-linkers. Under scanning electron microscopy （SEM）, X-ray photoelectron spectroscopy （XPS） and by ion binding experiment, the products were identified. Results The contents of sulphur element on the surfaces of coupled composition and entrapped composition were 1.5 % and 0.09 % respectively. The amounts of ions attaching to the coupled composition were 0. 126 mg at 12 h and 0.231 mg at 24 h, while amounts of ions attaching to the entrapped composition were 0. 053 mg at 12 h and 0. 102 mg at 24 h respectively. The coupled composition showed greater ability to attach to ions than that of the entrapped composition. Conclusion The coupled material established the basement of osteoinductive property and biomimetic mineralized ability for the bone tissue engineering.