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Most of biomaterials come in direct contact with the body, making standardized methods of evaluation and validation of biocompatibility an important aspect to biomaterial development. However, biomaterial validation guidelines have not been fully established, until now. This study was to compare the in vitro behavior of osteoblasts cultured on nanomaterial TiO2 surfaces to osteoblast behavior on culture plates. Comparisons were also made to cells grown in conditioned media (CM) that creates an environment similar to the in vivo environment. Comparisons were made between the different growth conditions for osteoblast adhesion, proliferation, differentiation, and functionality. We found that the in vivo-like system of growing cells in concentrated CM provided a good validation method for biomaterial development and in vivo implant therapy. The TiO2 materials were biocompatible, showing similar behavior to that observed in vivo. This study provided valuable information that would aid in the creation of guidelines into standardization and evaluation of biocompatibility in TiO2 biomaterials.

The degree of self-assembly and the size variation of nanotubular structures in anodic titanium oxide prepared by the anodization of titanium in ethylene glycol containing 0.25 wt % NH4F at 40 V were investigated as a function of anodization time. We found that the degree of self-assembly and the size of the nanotubes were strongly dependent on thickness deviation and thus indirectly on anodization time, as the thickness deviation was caused by the dissolution of the topmost tubular structures at local areas during long anodization. A large deviation in thickness led to a large deviation in the size and number of nanotubes per unit area. The dissolution primarily occurred at the bottoms of the nanotubes (Dbottom) in the initial stage of anodization (up to 6 h), which led to the growth of nanotubes. Dissolution at the tops (Dtop) was accompanied by Dbottom after the formed structures contacted the electrolyte after 12 h, generating the thickness deviation. After extremely long anodization (here, 70 h), Dtop was the dominant mode due to increase in pH, meaning that there was insufficient driving force to overcome the size distribution of nanotubes at the bottom. Thus, the nanotube array became disorder in this regime.

Sjögren's syndrome is a chronic autoimmune disorder characterized by lymphocytic infiltration of the lacrimal and salivary glands, leading to dryness of eyes (kerato-conjunctivitis sicca) and mouth (xerostomia). The skin lesions in Sjögren's syndrome are usually manifested as xeroderma, but sometimes appear as annular erythema or vasculitis. Central nervous system symptoms may be presented as one of extraglandular manifestations, though rare in incidence, and need differential diagnosis from multiple sclerosis. We report a case of a 45-year-old woman diagnosed as multiple sclerosis at first but later as neurologic manifestation of primary Sjögren's syndrome, showing signs of multiple sclerosis and cutaneous erythematous lesions.