| Research Abstract |
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.
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