HEALING PROCESS OF THE CALVARIAL DEFECT FILLED WITH HYDROXYLAPATITE AND TGF-beta IN RAT

ABSTRACT

hydroxylapatite(HA) and TGF-beta in Rat. 72 Sprague-Dawly rats were divided into 3 groups, control and two experimental groups. Bony defect were artificially prepared in the calvaria of all 72 rats and followed by implantation of HA (experimental group of 24 rats) and HA + TGF-beta (another experimental group of 24 rats) into the defects. Sequential sacrifice was performed at 1, 2, 4, 6, 8, 12 weeks of experiment. Obtained specimen was stained with Hematoxylin and Eosin, Masson's Trichrome and Immunohistochemistry. The results were as follows; 1. Granulation tissue was prominent on control group in 1 and 2 weeks. Bony defects were filled with dense fibrous tissue through the whole experimental period and osteoinduction could not be observed in all groups. 2. Inflammatory cell infiltration was prominent on control group in 1 and 2 weeks and osteoclastic activity was high in HA implanted experimental group at 1 and 2 weeks. 3. Inflammatory cell infiltration was less and maturation of fibrous tissue could be found on HA + TGF-beta implanted experimental group at 1 and 2 weeks. 4. Osteoconduction activity was high in HA + TGF-beta implanted experimental group at 2 and 4 weeks but there was no difference after 6 weeks among 3 group. 5. In grafted site of HA + TGF-beta implanted group, osteonectin expression was slightly increased from 1 week to 6 weeks. In the host site, it was increased from 1 to 4 weeks. 6. In grafted site of HA + TGF-beta implanted group, osteocalcin expression was high at 4 weeks. In the host site, we could find the difference among 3 group. From above results, the HA with mixture of TGF-beta has the potentiality of potentiality of promoting bone formation in the bony defect area in the rat.