In vivo reactions of beta -tricalcium phosphate and hydroxyapatite single crystals with bone marrow of rats i. reactions of hydroxyapatite single crystals

摘要

Single crystals of hydroxyapatite (HAp) were implanted in femoral bones of rats. In vivo reactions of the crystals with the bone marrow were estimated by histological and cytochemical techniques. The crystals of HAp were synthesized by hydrothermal methods. The obtained crystals was hexagonal prismatic shape lengthened along c-axis and 0.1x0.1x5 mm~3 in maximum. The single crystals were inserted in the femoral medullary cavities of 6-week-old Wister rats using spinal needles from the drilled hole of 1.1 mm in diameter on the trochlea femoris. A new bone formation around the HAp single crystals was observed at 5 days after the implantation by H-E stained sections. The area of newly formed bone decreased with time in the range from 5 to 14 days. Osteoblasts being positive for ALP existed around the crystals and newly formed bones at 5,7 and 14 days after the implantation. TRAP-positive multinucleate great cells assigned to osteoclast appeared at 7 and 14 days. The reaction of HAp single crystals with bone marrow has no considerable difference from that of the sintered HAp ceramics.