title: Axial vascularization of a large volume calcium phosphate ceramic bone substitute in the sheep AV loop model.
abstract: Vascularization still remains an obstacle to engineering of bone tissue with clinically relevant dimensions. Our aim was to induce axial vascularization in a large volume of a clinically approved biphasic calcium phosphate ceramic by transferring the arteriovenous (AV) loop approach to a large animal model. HA/beta-TCP granula were mixed with fibrin gel for a total volume of 16 cm(3), followed by incorporation into an isolation chamber together with an AV loop. The chambers were implanted into the groins of merino sheep and the development of vascularization was monitored by sequential non-invasive magnetic resonance imaging (MRI). The chambers were explanted after 6 and 12 weeks, the pedicle was perfused with contrast agent and specimens were subjected to micro-computed tomography (micro-CT) scan and histological analysis. Sequential MRI demonstrated a significantly increased perfusion in the HA/beta-TCP matrices over time. Micro-CT scans and histology confirmed successful axial vascularization of HA/beta-TCP constructs. This study demonstrates, for the first time, successful axial vascularization of a clinically approved bone substitute with a significant volume in a large animal model by means of a microsurgically created AV loop, thus paving the way for the first microsurgical transplantation of a tissue-engineered, axially vascularized bone with clinically relevant dimensions.
authors: Department of Plastic and Hand Surgery, University Hospital of Erlangen, Erlangen, Germany. Justus.beier@uk-erlangen.de
authors: Justus P
authors: JP
authors: Beier
authors: Raymund E
authors: RE
authors: Horch
authors: Andreas
authors: A
authors: Hess
authors: Andreas
authors: A
authors: Arkudas
authors: Johanna
authors: J
authors: Heinrich
authors: Johanna
authors: J
authors: Loew
authors: Heinz
authors: H
authors: Gulle
authors: Elias
authors: E
authors: Polykandriotis
authors: Oliver
authors: O
authors: Bleiziffer
authors: Ulrich
authors: U
authors: Kneser
mesh_terms: D000818:Animals; D001808:Blood Vessels; D018786:Bone Substitutes; D002130:Calcium Phosphates; D002516:Ceramics; D003287:Contrast Media; D008279:Magnetic Resonance Imaging; D023421:Models, Animal; D012756:Sheep; D014057:Tomography, X-Ray Computed
chemical_list: D018786:Bone Substitutes; D002130:Calcium Phosphates; D003287:Contrast Media; C020243:calcium phosphate