title: Quantitative screening of engineered implants in a long bone defect model in rabbits.
abstract: We have standardized a long bone defect model in rabbits to quantitatively compare the bone healing performance of engineered biological implants and have tested the bone healing efficiency of porous cylindrical scaffolds (ø-h, 6-20 mm [diameter 6 mm, height 20 mm] porosity, 70%) that were produced from hydroxyapatite (HA), titanium (Ti), and a novel biodegradable polymer-bioceramic composite (PH70alphaTCP). Scaffolds were perfused with or without 20 x 10(6) rabbit periosteal cells (RPCs) in a bioreactor and implanted in a standardized 2 cm defect in rabbit tibiae. X-rays revealed that new bone had formed at 3 weeks after creation of the defects. At sacrifice after 10 weeks, bone corticalization was observed in the majority of animals. Although PH70alphaTCP scaffolds did not inhibit callus formation, histomorphometric analysis revealed that there was no bone within the biomaterial, in contrast to HA and Ti scaffolds (bone volume ranging from 10% to 25%). We found that Ti and HA scaffold had good osteoconductive properties, but only HA scaffolds seeded with RPCs contributed to long bone mechanical functionality, with the maximum energy and angle being 308% and 155% greater than in control defects without scaffold.
authors.affiliation: Laboratory for Skeletal Development and Joint Disorders, Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: Astrid D
authors.initials: AD
authors.lastname: Bakker
authors.forename: Jan
authors.initials: J
authors.lastname: Schrooten
authors.forename: Tim
authors.initials: T
authors.lastname: van Cleynenbreugel
authors.forename: Johan
authors.initials: J
authors.lastname: Vanlauwe
authors.forename: Jan
authors.initials: J
authors.lastname: Luyten
authors.forename: Evert
authors.initials: E
authors.lastname: Schepers
authors.forename: Peter
authors.initials: P
authors.lastname: Dubruel
authors.forename: Etienne
authors.initials: E
authors.lastname: Schacht
authors.forename: Johan
authors.initials: J
authors.lastname: Lammens
authors.forename: Frank P
authors.initials: FP
authors.lastname: Luyten
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D019149:Bioreactors; D001842:Bone and Bones / Q000378:metabolism / Q000473:pathology*; D002470:Cell Survival; D002478:Cells, Cultured; D017886:Durapatite / Q000737:chemistry; D017102:Fracture Healing; D008422:Materials Testing; D016062:Porosity; D019736:Prostheses and Implants; D011817:Rabbits; D015203:Reproducibility of Results; D023822:Tissue Engineering / Q000379:methods*; D014025:Titanium / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D017886:Durapatite; D014025:Titanium