title: Osteoinduction with highly purified beta-tricalcium phosphate in dog dorsal muscles and the proliferation of osteoclasts before heterotopic bone formation.
abstract: 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.
authors.affiliation: 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.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kondo
authors.forename: Akira
authors.initials: A
authors.lastname: Ogose
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Tokunaga
authors.forename: Hajime
authors.initials: H
authors.lastname: Umezu
authors.forename: Katsumitsu
authors.initials: K
authors.lastname: Arai
authors.forename: Naoko
authors.initials: N
authors.lastname: Kudo
authors.forename: Makiko
authors.initials: M
authors.lastname: Hoshino
authors.forename: Hikaru
authors.initials: H
authors.lastname: Inoue
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Irie
authors.forename: Koichi
authors.initials: K
authors.lastname: Kuroda
authors.forename: Hisashi
authors.initials: H
authors.lastname: Mera
authors.forename: Naoto
authors.initials: N
authors.lastname: Endo
mesh_terms: 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
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; C485817:beta-tricalcium phosphate; D002403:Cathepsins; D056657:Cathepsin K