含Arg-Gly-Asp肽改性PLGA-[ASP-PEG]矿化的研究

Mineralization of PLGA-[ASP-PEG] Modified with RGD-containing Peptide

将含Arg-Gly-Asp(RGD)肽对多孔的PLGA-[ASP-PEG]表面进行改性,然后置于仿体液中两周,探讨肽改性的PLGA-(PEG-ASP)在仿体液中的矿化情况。通过交联剂Sulfo-LC-SPDP把肽接枝到PLGA-[ASP-PEG],X射线光电子能谱仪(X-ray photoelectron spectroscopy,XPS)鉴定;肽改性PLGA-[ASP-PEG]为实验组(Experiment group,EG),PLGA-[ASP-PEG]为对照组(Control group,CG),均置于仿体液中两周,扫描电子显微镜(Scanning electron microscope,SEM)、X射线能谱仪(Energy dispersive analysis system of X-ray,EDS)及X射线衍射仪(X-ray diffractometry,XRD)对矿化情况进行分析。XPS检测肽改性PLGA-[ASP-PEG]表面硫元素结合能为164eV,碳、硫元素的含量比值(C/S)为99.746∶0.1014;SEM示在EG表面及内部呈现连续的较为致密的矿化层,CG仅见分散稀疏的矿化层;EDS及XRD结果表明矿化物主要成分为羟基磷灰石,EG矿化物中钙/磷比值为1.60,CG矿化物中钙/磷比值为1.52。含RGD肽为矿化提供了丰富的功能基团,PLGA-(PEG-ASP)经肽修饰矿化后,获得了与天然骨基质相似的微观结构。

The RGD-containing peptide was used tO modify the surface of porous PLGA-[-ASP-PEG], and was incubated in the modified simulated body fluid （mSBF） for two weeks. The mineralization of PLGA-[ASP-PEG] was explored. The active peptide was used to modify PLGA-[-ASP-PEG] through cross-linker （Sulfo-LC-SPDP）, characterized by X-ray photoelectron spectroscopy （XPS）; the peptide-modified PLGA-[ASP-PEG] （Experiment group, EG） and PLGA-[-ASP-PEG] without modification （Control group, CG） were all incubated in mSBF for two weeks, confirmed by observation of Scanning electron microscope（SEM） and measurements of Energy dispersive analysis system of X-ray （EDS） and X-ray diffractometry （XRD）. XPS indicated that the binding energy of sulphur in EG was 164eV, and the ratio of carbon to sulphur in EG was 99. 746：0. 1014, however, sulphur was not detected in CG~ SEM analysis demonstrated that the mineralization layers were more consecutive and compact in EG than in CG. The results of EDS and XRD indicated that the main component of mineral was hydroxyapatite, and the ratio of Ca/P was 1.60 in EG, and 1.52 in CG. RGD-containing peptide provided enough functional groups for mineralization; the mineralized peptide-modified PLGA-[ASP-PEG] possessed the bonelike microstructure.