| Summary: | 碩士 === 國立成功大學 === 製造工程研究所碩博士班 === 94 === This study aims at investigating the effect of nano-surface roughnesss of Ti-6Al-4V alloy on the shot-team responses of Murine NIH-3T3 fibroblasts. Titanium alloy disks are prepared by wet grinding with grit silicon carbide paper and polishing with Al2O3 powder to the surface roughness with Ra values of 2.31, 3.67, 4.65, 9.52, 18.31 and 28.02nm, respectively. After polishing and cleaning, each specimen is passivated by 400℃ air for 45 min. Readings are collected for the nano-surface roughness, surface chemical properties, wettability, and surface potential. The nano-surface roughness is measured by scanning probe microscope (SPM), chemical properties of surface oxide by X-ray Photoelectron Spectroscopy (XPS), wettability by static contact angle assessment method, and surface potential by Zeta Potential analyzer. It has been observed the heat-treatment increased the surface roughness with corresponding Ra values of 2.75, 3.98, 5.26, 11.72, 20.84 and 30.34nm. Significant differences in wettability have been detected among six sample groups. The contact angle increases with the roughness. Cytocompatibility is assessed using cell adhesion, cell proliferation and morphology. While cytodetachment method measures the initial adhesive force for individual cells, Scanning Electron Microscopy (Fe-SEM) is employed to take images of cell morphology, and cell proliferation is measured by MTT. The initial cell adhesive force of fibroblasts ranges from 0.055μN to 0.193μN for samples of six different nano-surface roughness. It has been observed that cell adhesive force increases with the roughness. Differences among expressions of cell proliferation on all six groups of samples are statistically insignificant. Experimental results revealed that nano-surface roughness affect not only the fibroblast-titanium interaction but also wettability and surface potential.
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