RGD肽修饰壳聚糖作为种植体表面基因载体的研究

目的 探索改善钛种植体表面处理的新方法，提高种植体植入后成骨效率。方法 将RGD肽与壳聚糖（CS）通过酰化反应发生偶联形成RGD-CS，采用复凝聚法制备RGD-CS/pDNA复合体，并将RGD-CS/pDNA复合体接枝到经物理、生化处理后的纯钛表面。采用红外光谱仪和元素分析仪对 RGD-CS进行化学结构的表征检测，凝胶电泳阻滞试验结合原子力显微镜观察RGD-CS对质粒的包裹情况及RGD-CS/pDNA复合体的形态， EB染色法检测钛片表面 RGD-CS/pDNA复合体的接枝效果。结果 红外光谱检测结合元素分析表明，CS和RGD肽偶联成功；凝胶电泳阻滞试验结合原子力显微镜观察表明，在N/P≥2时，RGD-CS与pDNA完全复合，RGD-CS/pDNA复合体呈类球形；EB染色表明RGD-CS/pDNA复合体接枝钛片成功。结论 经RGD肽修饰的壳聚糖可以携带 pDNA作为钛种植体表面质粒包装的载体。

RGD peptide-modified chitosan as a gene carrier of implant surface

Objective This study is conducted to explore new methods to perform surface biomodification of titanium implants and improve osteogenic efficiency. Methods An RGD peptide and chitosan (CS) were combined by acylation reaction, forming RGD-CS. An RGD-CS/pDNA complex was subsequently prepared using a complex coacervation method and grafted on a pure titanium surface after physical and biochemical treatments were performed. The chemical structural characteristics of RGD-CS were evaluated using an infrared spectrometer and an elemental analyzer. The shape of this complex was then assessed by gel electrophoresis combined with atomic force microscopy. The grafting effect of this complex on the titanium surface was detected by EB staining. Results CS and RGD peptides were coupled by an amide bond. The RGD-CS/pDNA complex was completely composited at N/P≥2. Atomic force microscopy results showed that the morpho-logy of this complex was mainly spherical. EB staining experiments showed that this complex was successfully grafted on the titanium plate. Conclusion RGD peptide-modified CS can be used as a titanium implant surface plasmid package carrier of pDNA.