Abstract
Purpose :
Titania (TiO2) and titania-based materials are candidate bioceramics for use in the repair of human tissues, including the fabrication of corneal implant skirts. The manufacture of mechanically strong and biocompatible TiO2 materials is of vital importance for these applications. This study was aimed at optimizing the selection of raw powder and sintering conditions for TiO2 ceramics.
Methods :
TiO2 compacts were synthesized from five raw powders, denoted as Altair, Inframat, Alfa, Materion and Amperit, respectively, by spark plasma sintering using different sintering parameters. The samples were evaluated with regard to their sintering behaviour, microstructure and mechanical properties using scanning electron microscopy, X-ray diffraction, Raman spectroscopy, deionized water contact angle analaysis using a Theta optical tensiometer and nanoindenter. To assess biocompatibility human corneal stromal fibroblasts were cultured on the materials and assessed for cell viability using calcein AM and ethidium homodimer-1, and click-iT for cell proliferation.
Results :
The XRD and Raman results confirmed that the anatase TiO2 phase in the Inframat powder had converted completely to rutile TiO2 phase after sintering at 900°C and above. The nanoindentation results indicated that among the five types of TiO2 samples sintered at 1100 °C, the Inframat pellets possessed the highest Young’s modulus and hardness. In addition, when Materion samples were employed to study the effects of SPS parameters, a higher sintering temperature in the range of 1100–1300 °C decreased the mechanical properties of sintered pellets. Culture of human corneal stromal fibroblasts on the sintered sample surfaces showed that comparably high cell viability and proliferation were observed on all TiO2 samples except Amperit compared to positive control. Furthermore, cells cultured on Inframat TiO2 sintered in the temperature range of 900–1300°C exhibited viability and formation of focal adhesion complex similar to those on control, and those prepared at 1100°C.
Conclusions :
In conclusion, Inframat TiO2 consolidated at 1100 °C by SPS was the best formulation for the preparation of mechanically strong and biocompatible Keratoprosthesis skirt.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.