title: Efficacy of novel synthetic bone substitutes in the reconstruction of large segmental bone defects in sheep tibiae.
abstract: The treatment of large bone defects, particularly those with segmental bone loss, remains a significant clinical challenge as current approaches involving surgery or bone grafting often do not yield satisfactory long-term outcomes. This study reports the evaluation of novel ceramic scaffolds applied as bone graft substitutes in a clinically relevant in vivo model. Baghdadite scaffolds, unmodified or modified with a polycaprolactone coating containing bioactive glass nanoparticles, were implanted into critical-sized segmental bone defects in sheep tibiae for 26 weeks. Radiographic, biomechanical, μ-CT and histological analyses showed that both unmodified and modified baghdadite scaffolds were able to withstand physiological loads at the defect site, and induced substantial bone formation in the absence of supplementation with cells or growth factors. Notably, all samples showed significant bridging of the critical-sized defect (average 80%) with evidence of bone infiltration and remodelling within the scaffold implant. The unmodified and modified baghdadite scaffolds achieved similar outcomes of defect repair, although the latter may have an initial mechanical advantage due to the nanocomposite coating. The baghdadite scaffolds evaluated in this study hold potential for use as purely synthetic bone graft substitutes in the treatment of large bone defects while circumventing the drawbacks of autografts and allografts.
authors.affiliation: Biomaterials and Tissue Engineering Research Unit, School of AMME, University of Sydney, Sydney, NSW 2006, Australia. These authors contributed equally.
authors.forename: Jiao Jiao
authors.initials: JJ
authors.lastname: Li
authors.forename: Seyed-Iman
authors.initials: SI
authors.lastname: Roohani-Esfahani
authors.forename: Colin R
authors.initials: CR
authors.lastname: Dunstan
authors.forename: Terrence
authors.initials: T
authors.lastname: Quach
authors.forename: Roland
authors.initials: R
authors.lastname: Steck
authors.forename: Siamak
authors.initials: S
authors.lastname: Saifzadeh
authors.forename: Peter
authors.initials: P
authors.lastname: Pivonka
authors.forename: Hala
authors.initials: H
authors.lastname: Zreiqat
mesh_terms: D000818:Animals; D018786:Bone Substitutes / Q000008:administration & dosage* / Q000138:chemical synthesis*; D002516:Ceramics / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008422:Materials Testing; D012756:Sheep; D017640:Silicates / Q000737:chemistry*; D013978:Tibial Fractures / Q000473:pathology / Q000628:therapy*; D023822:Tissue Engineering / Q000295:instrumentation / Q000379:methods; D054457:Tissue Scaffolds; D016896:Treatment Outcome
chemical_list: D018786:Bone Substitutes; C000592768:Ca(3)ZrSi(2)O(9); D017640:Silicates