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Updated: May 10, 2026

Calvarial Model of Bone Augmentation in Rabbit for Assessment of Bone Growth and Neovascularization in Bone Substitution Materials
Published on: August 13, 2019
Evaluation of a β-calcium metaphosphate bone Graft containing bone morphogenetic protein-7 in rabbit maxillary
Borvornwut Buranawat1, Lucy Di Silvio, Sanjukta Deb
1Department of Biomaterials, Dental Institute, King's College London, London, UK.
Background:
Calcium phosphate-based materials have been widely used as bone substitutes and more recently are being exploited together with growth factors as bone tissue engineering scaffolds regulating cell behavior. The aim of this study is to evaluate the in vitro and in vivo response to a newly developed calcium metaphosphate (CMP) bone graft, with and without bone-stimulating growth factor.
Methods:
Porous scaffolds of CMP were developed and extensively tested in vitro. Subsequently, CMP grafts with osteogenic protein-1 (OP-1) (test) and without OP-1 (control) were implanted into experimental rabbit maxillary bone defects. Animals were sacrificed at 2, 4, and 8 weeks, and samples were examined with microcomputed tomography (micro-CT) and processed for histomorphometric analysis.
Results:
At 8 weeks, the scaffolds containing OP-1 induced greater bone formation (P = 0.018) than CMP alone, based on histomorphometric evaluation (percentage bone area: test: 57.1 ± 5.6; control: 49.4 ± 7.7) and micro-CT analysis (percentage bone volume density: test: 63.46 ± 5.61; control: 51.20 ± 6.71). Thus, these data indicated that both test and control CMP grafts showed a good degree of bone formation. Furthermore, the CMP materials showed signs of resorption from 4 weeks, and no graft materials were observed at 8 weeks.
Conclusions:
In vitro, the OP-1 loaded graft demonstrated a release profile and bioactivity over a 28-day period. In vivo testing confirmed enhanced bone formation of the OP-1 loaded graft after 8 weeks of healing.

