具有骨诱导活性的仿生骨基质材料的制备

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24h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、0．102mg。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。

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

Objective To prepare a new biomimetic bone matrix material for tissue engineering by integrating polypeptide,which has excellent osteoinduction,with modified PLGA scaffold using cross- linkers.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 exper- iment,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 attach- ing to the coupled composition were 0.126 mg at 12 h and 0.231 mg at 24 h,while amounts of ions at- taching 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.Con- clusion The coupled material established the basement of osteoinductive property and biomimetic miner- alized ability for the bone tissue engineering.