title: Interconnected porous hydroxyapatite ceramics for bone tissue engineering.
abstract: Several porous calcium hydroxyapatite (HA) ceramics have been used clinically as bone substitutes, but most of them possessed few interpore connections, resulting in pathological fracture probably due to poor bone formation within the substitute. We recently developed a fully interconnected porous HA ceramic (IP-CHA) by adopting the 'foam-gel' technique. The IP-CHA had a three-dimensional structure with spherical pores of uniform size (average 150 microm, porosity 75%), which were interconnected by window-like holes (average diameter 40 microm), and also demonstrated adequate compression strength (10-12 MPa). In animal experiments, the IP-CHA showed superior osteoconduction, with the majority of pores filled with newly formed bone. The interconnected porous structure facilitates bone tissue engineering by allowing the introduction of mesenchymal cells, osteotropic agents such as bone morphogenetic protein or vasculature into the pores. Clinically, we have applied the IP-CHA to treat various bony defects in orthopaedic surgery, and radiographic examinations demonstrated that grafted IP-CHA gained radiopacity more quickly than the synthetic HA in clinical use previously. We review the accumulated data on bone tissue engineering using the novel scaffold and on clinical application in the orthopaedic field.
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita 565-0871, Japan. yhideki@ort.med.osaka-u.ac.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Tamai
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Murase
authors.forename: Akira
authors.initials: A
authors.lastname: Myoui
mesh_terms: D000328:Adult; D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000601:surgery / Q000628:therapy; D018786:Bone Substitutes / Q000737:chemistry*; D016025:Bone Transplantation; D002356:Cartilage / Q000601:surgery; D002516:Ceramics; D002675:Child, Preschool; D002986:Clinical Trials as Topic; D017886:Durapatite / Q000737:chemistry*; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D059630:Mesenchymal Stem Cells; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000639:trends; D051381:Rats; D013710:Tendons / Q000601:surgery; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D019485:Bone Morphogenetic Proteins; D018786:Bone Substitutes; D017886:Durapatite