Biomaterial implants have attracted increasing attention in the past few decades in the healthcare field, for the increasing demands for regenerative medicine and the serious problem of aging trend. Titanium has become one of the most important metallic biomaterials for its good mechanical properties, corrosion resistance, and biocompatibility in clinical applications, like bone implant and endovascular implant. Unfortunately, some issues still exist at the interface between titanium and tissues. It is widely recognized that cell behaviors can be affected by the properties of material surface, including surface topography, chemistry, wettability, and charge. The present work focuses on topography modification of material surface.

Some researchers have already found out that mic...[ Read more ]

Biomaterial implants have attracted increasing attention in the past few decades in the healthcare field, for the increasing demands for regenerative medicine and the serious problem of aging trend. Titanium has become one of the most important metallic biomaterials for its good mechanical properties, corrosion resistance, and biocompatibility in clinical applications, like bone implant and endovascular implant. Unfortunately, some issues still exist at the interface between titanium and tissues. It is widely recognized that cell behaviors can be affected by the properties of material surface, including surface topography, chemistry, wettability, and charge. The present work focuses on topography modification of material surface.

Some researchers have already found out that micro- or nano- structure could affect cell behavior, like adhesion, and proliferation. However, little work has been done on the biomaterials that have both micro and nano structures, which I name it hierarchical structure. I employed the photolithography technique to fabricate micropattern on substrate, and then sputtered chromium on the surface to serve as a mask during the following dry etching process. Dry etching process is performed by HKUST ICP dry etching system. SF₆ was the feed gas that I used to generate plasma and radicals to bombard the surface under the modified parameters, including ICP source power, bias power, pressure, gas flux and time duration. After obtaining micropatterns, hydrothermal process will be applied to form nanostructure, which is directly grown onto micropatterns surface. The nanostructure could also be altered by various temperatures, solution concentrations and reaction time. After acid treatment (ion-exchange process) and heat treatment (anneal process), the final product is obtained: titanium bulk materials with hierarchical structures on the surface.

Bioactivity of the hierarchical structure substrate is tested in-vitro with SBF and SCP solution, and the nanostructure on the surface might contribute to the positive bioactivity effects.