Preparation of Mesoporous Hydroxylapatite Ceramics Using Polystyrene Microspheres as Template

Mesoporous hydroxylapatite was prepared by Liquid phase precipitation method, using Polystyrene microspheres as template. Polystyrene microspheres mixed uniformly with the prepared hydroxylapatite slurry, then the mixture dryed and sintered at reasonable temperature, mesoporous hydroxylpatite ceramics were obtained. The phase constituent was analyzed by X-ray diffraction (XRD) and the microstructure was observed under scanning electron microscopy (SEM). The results showed that the prepared mesoporous hydroxylapatite ceramics were of high purity and their pores were evenly distributed, with big pore 0.8-1.0 um and small pore 30-80nm in diameter.

In Vitro Generation of Cartilage-Carrier-Constructs on Hydroxylapatite Ceramics with Different Surface Structures

Tissue engineering approaches for healing cartilage defects are partly limited by the inability to fix cartilage to bone during implantation. To overcome this problem, cartilage can be - already in vitro - generated on a ceramic carrier which serves as bone substitute. In this study, the influence of a hydroxylapatite carrier and its surface structure on the quality of tissue engineered cartilage was investigated. Application of the carrier reduced significantly biomechanical and biochemical properties of the generated tissue. In addition, slight changes in the quality of the formed matrix, in the adhesive strength between cartilage and biomaterial and in attachment and proliferation of a chondrocyte monolayer could be observed for commercial grade carriers, with respect to modified topographies obtained by smooth grinding/polishing. These first results demonstrated an influence of the carrier and its surface structure, but further research is needed for explaining the described effects and for optimization of cartilage-carrier-constructs.