Study on negative ion-implanted biomaterials to induce vascular endothelial cells and neural cells

本研究的目的是研究和开发负离子植入材料，以辅助和诱导修复和再生受损的生物组织，如血管和神经系统。采用中性和电离碱性轰击型重负离子源（NIABNIS），首先选择银负离子（Ag^-）注入聚苯乙烯（PS）和组织培养聚苯乙烯（TCPS），剂量为10^<14> ~ 10^<16>离子“Jm^<-2>”，离子能量相对较低，为5-30 keV。研究了Ag^-植入TCPS和PS的表面性能和生物相容性。采用二次离子质谱（SIMS）、x射线光电子能谱（XPS）、傅里叶变换红外光谱（FTIR）、微拉曼光谱（microraman spectroscopy， FTIR）和接触角测量等方法研究了Ag^-注入PS的表面。由于Ag^——的注入，聚苯乙烯表面发生降解，从而变得更亲水。Ag^-移植后血管内皮细胞（HUVEC）密度明显降低，而Ag^-移植后血管内皮细胞密度明显增加。此外，我们还观察到细胞从Ag^—植入的PS区诱导到PS区，并在与Ag^—植入的TCPS区相邻的TCPS区上平行排列成条形。小鼠来源的神经细胞以与血管内皮细胞相同的方式沉积在Ag^-植入的PS区。此外，还观察到神经突的生长特异性地发生在Ag^-植入的PS区。C^-、Cu^-和Ag^-植入的PS和TCPS对神经细胞的培养没有显著差异，但其对细胞的作用机制尚不清楚，需要进一步研究。

The purpose of this research is to study and develop on negative ion-implanted materials which assist and induce to repair and regenerate wounded biological tissues, such as vascular blood vessels and neural systems. Silver negative ions (Ag^-) were chosen first to be implanted to polystyrene (PS) and tissue culture polystyrene (TCPS) by using neutral and ionized alkaline bombardment-type heavy negative ion sources (NIABNIS) in doses of 10^<14> to 10^<16> ions "Jm^<-2> at relatively low ion energies of 5-30 keV.The surface property and biocompatability of Ag^--implanted TCPS and PS were investigated. Surfaces of Ag^--implanted PS were studied by means of secondary ion mass spectrometry (SIMS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and micro-Raman spectroscopy, and contact angle measurement. As a result of Ag^--implantation, the polystyrene surfaces underwent degradation, thereby becoming more hydrophilic.The cell density of vascular endothelial cells (HUVEC) was observed to decrease remarkably on Ag^--implanted TCPS, compared with that on TCPS, while the cell density was observed to increase extremely on Ag^--implanted PS than on the untreated PS region. In addition, the cells were observed to be induced on Ag^--implanted PS region from PS region, and to be lined up in parallel on the TCPS region contiguous to the Ag^--implanted TCPS region in the shape of stripe. Murine-derived neural cells were observed to settle on the Ag^--implanted PS region in the manner same as vascular endothelial cells. In addition, the neurite outgrowth was also observed to develop specifically on the Ag^--implanted PS region. There was no significant difference for the culture of neural cells among on C^-, Cu^-, and Ag^--implanted PS and TCPS, although the mechanism for effects on cells is unclear and the further study is necessary.