Osteoinduction with highly purified beta-tricalcium phosphate in dog dorsal muscles and the proliferation of osteoclasts before heterotopic bone formation.
The aim of the study was to examine the chronological histology of osteoinduction of highly purified beta-tricalcium phosphate (beta-TCP) implanted in dog dorsal muscles. Specimens were harvested on days 14, 28, 42, 56, 112 and 168 after implantation, and were analyzed by hematoxylin and eosin (HE) staining, tartrate-resistant acid phosphatase (TRAP) staining, immunohistochemistry, in situ hybridization, and silver impregnation. After day 28, abundant TRAP- and cathepsin K-positive multinucleated cells adhered to beta-TCP, suggesting that these cells are osteoclasts that can resorb beta-TCP. On day 56, new bone was formed and alpha1 chain of type I procollagen mRNA-positive osteoblasts lined the newly formed bone. Silver impregnation showed abundant collagen fibrils within the beta-TCP micropores. These results suggest that micropores function as a storage space for extracellular matrix components, including collagen. Newly formed bone never degenerated in the late stage, suggesting that beta-TCP has good biocompatibility and this material retains the conditions appropriate for osteointegration and bioresorption. In conclusion, beta-TCP has osteoinductivity after implantation in dog dorsal muscles without use of bone marrow cells or osteoinductive cytokines. The appearance of a large number of active osteoclasts precedes new bone formation.
Kondo
Naoki
N
Division of Orthopedic Surgery, Department of Regenerative and Transplant Medicine, Niigata University Graduate School of Medical and Dental Sciences, 757-1 Asahimachi Dori, Niigata-shi, Niigata 951-8510, Japan.
Ogose
Akira
A
Tokunaga
Kunihiko
K
Umezu
Hajime
H
Arai
Katsumitsu
K
Kudo
Naoko
N
Hoshino
Makiko
M
Inoue
Hikaru
H
Irie
Hiroyuki
H
Kuroda
Koichi
K
Mera
Hisashi
H
Endo
Naoto
N
D000818:Animals; D001672:Biocompatible Materials; D001846:Bone Development / Q000187:drug effects*; D002130:Calcium Phosphates / Q000494:pharmacology*; D056657:Cathepsin K; D002403:Cathepsins / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D004285:Dogs; D005260:Female; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D018482:Muscle, Skeletal / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D010010:Osteoclasts / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology
D001672:Biocompatible Materials; D002130:Calcium Phosphates; C485817:beta-tricalcium phosphate; D002403:Cathepsins; D056657:Cathepsin K