Oxygen plasma with different treatment powers and durations was utilized to modify the biomedical pure titanium (Ti) surface in the present study. The superficial, microstructural and biological properties of the plasma-oxidized samples were investigated using the electron microscopy, X-ray photoemission spectroscopy, grazing incidence X-ray diffractometer, contact angle goniometer and blood clotting time assay. During different treatment powers and durations, the island-like nanostructural rutile-TiO 2 layer and dimple-like nanostructural rutile-TiO 2 layer were generated on the surfaces of the plasma-oxidized samples, respectively. It was also found that the plasma-oxidized sample with a rough oxide layer resulted in the formation of a higher wettability. Moreover, the blood clotting time assay indicated that the plasma-oxidized samples exhibited the adhesion behaviors of red blood cells. As the Ti surface underwent plasma oxidation at 280 W for 30 min, it not only generates a rough nanostructural rutile-TiO 2 layer, but also presents an excellent hemocompatibility. Therefore, these findings demonstrate that oxygen plasma modification is a potential approach to promote the hemocompatibility of biomedical pure Ti surface.

The microstructural, in vitro and in vivo properties of the microwave-synthesized samples were investigated using the optical microscope, scanning electron microscope, X-ray diffraction, differential scanning calorimeter, contact angle goniometer, cell cytotoxicity assay, and chick chorioallantoic membrane (CAM) model in the study. When the calcium sulfate dihydrate (CSD) precursor underwent microwave irradiation treatment at temperatures between 100°C and 160°C, the crystal morphologies and crystalline structures were transformed from (tablet-like CSD (monoclinic)) ? (tablet-like CSD (monoclinic) + long column a-calcium sulfate hemihydrate (a-CSH, hexagonal)) ? (long column CSD (monoclinic) + short column a-CSH (hexagonal)) ? (uniform short column a-CSH (hexagonal)). The high-purity a-CSH with uniform short column crystals around 10 lm in length can be synthesized at 160°C for 10 minutes and exhibits a higher hydrophilic feature in blood. Moreover, the cell cytotoxicity assay indicated that the microwave-synthesized samples possessed well biocompatibility. In vivo results also demonstrated that the microwave-synthesized a-CSH not only induces angiogenesis formation but also facilitates osteogenesis. Therefore, the microwave-synthesized a-CSH is a promising bone graft substitute that can be applied in dental and orthopedic fields. K E Y W O R D Sbioceramics, biocompatibility, microstructure, microwaves, phase transformations Chin-Sung Chen,

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