title: Capillary vessel network integration by inserting a vascular pedicle enhances bone formation in tissue-engineered bone using interconnected porous hydroxyapatite ceramics.
abstract: The aim of the present study was to investigate the possibility of integrating porous hydroxyapatite (HA) ceramics with a capillary vessel network via insertion of a vascular pedicle, and to determine whether this procedure enhances new bone formation in tissue engineering of bone. First, synthetic interconnected porous HA (IP-CHA) was implanted subcutaneously into rat groin with or without insertion of superficial inferior epigastric vessels. At 6 weeks, IP-CHA with vascular insertion contained thick fibrous connective tissue with a number of large blood vessels that seemed to derive from the inserted vascular bundle. Next, IP-CHA loaded with recombinant human bone morphogenetic protein 2 (BMP, 2 or 10 microg/block) was implanted with or without vascular insertion. At 3 weeks, IP-CHA/BMP (10 microg) composite with vascular insertion exhibited abundant new bone formation in the pores of the deep portion close to the inserted vessels. In contrast, IP-CHA/BMP (10 microg) without vascular insertion showed poor bone formation. Histomorphometric analysis demonstrated that vascular insertion significantly increased new bone formation. In IP-CHAs with a lower dose of BMP (2 microg), no bone formation was found, with or without vascular insertion. These results suggest that the present system of integrating a vascular network with IP-CHA is a useful technique for bone tissue engineering.
authors.affiliation: Department of Orthopedics, Osaka University Graduate School of Medicine, Suita, Japan.
authors.forename: Shosuke
authors.initials: S
authors.lastname: Akita
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Tamai
authors.forename: Akira
authors.initials: A
authors.lastname: Myoui
authors.forename: Masataka
authors.initials: M
authors.lastname: Nishikawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Kaito
authors.forename: Kunio
authors.initials: K
authors.lastname: Takaoka
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
mesh_terms: D000818:Animals; D018786:Bone Substitutes; D001842:Bone and Bones / Q000098:blood supply* / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D002196:Capillaries / Q000637:transplantation*; D002516:Ceramics; D016503:Drug Delivery Systems / Q000379:methods; D004343:Drug Implants; D017886:Durapatite; D006133:Growth Substances / Q000494:pharmacology; D020007:Implants, Experimental; D008297:Male; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology*; D016062:Porosity; D051381:Rats; D017207:Rats, Sprague-Dawley; D023822:Tissue Engineering / Q000379:methods*; D019737:Transplants
chemical_list: D018786:Bone Substitutes; D004343:Drug Implants; D006133:Growth Substances; D017886:Durapatite