Entwicklung und Anwendungen von Biokeramik

Diameter of a Hollow Center in Cylindrical Hydroxyapatite Scaffold for Hard Tissue Formation

Abstract

N. Tsuji, M. Yoshikawa, H. Hayashi, and H. Ohgushi

The purpose of this study was to obtain an appropriate geometry of porous hydroxyapatite scaffold for hard tissue formation in most of the pores. Porous cylindrical hydroxyapatite structures with a hollow center as a scaffold were manufactured. The diameter of a hollow center was 2 or 3 mm. Bone marrow cells were obtained from bone shafts of femora of 6-week-old male Fischer 344 rats. The cell/hydroxyapatite composite scaffolds were implanted in dorsal subcutis of 7-week-old male Fischer 344 rats. They were removed 8 weeks postoperatively. Serially sectioned paraffin specimens were made and observed histologically. The ratio of pores including hard tissue to the number of total pores per a square centimeter of the cross-sectional area in the scaffolds was calculated. In the scaffold with a hollow center measuring 2mm in diameter, a new hard tissue formation was observed near the superficies and the number of pores including hard tissue was 260.6 ± 60.8/cm2. In the scaffold with a hollow center measuring 3mm in diameter, new hard tissue was observed between superficies and the wall of the hollow center. The number of pores including hard tissue was 589.6 ± 73.3/cm2.