Repair of the calvarial defect in goat model using magnesium-doped porous hydroxyapatite combined with recombinant human bone morphogenetic protein-2

Article type: Research Article

Authors: Deng, Liqing^{a; b; *} | Li, Donghai^{a; *} | Yang, Zhouyuan^a | Xie, Xiaowei^a | Kang, Pengde^{a; **}

Affiliations: [a] Department of Orthopaedics surgery, West China Hospital, Sichuan University, 37# Wainan Guoxue Road, Chengdu 610041, People’s Republic of China. E-mails: 604982346@qq.com, LiDh9090@163.com, yangzhouyuan1986@163.com, 459519596@qq.com, kangpd@163.com | [b] Department of Orthopaedics surgery, Hospital of Chengdu Office of People’s Government of Tibetan Autonomous Region, 20# Ximianqiaoheng street, Chengdu 610041, People’s Republic of China

Correspondence: [**] Corresponding author. Tel.: +86 28 85422426; Fax: +86 28 85423438; E-mail: kangpd@163.com.

Note: [*] Donghai Li and Liqing Deng contributed equally to this work and should be regarded as first co-author.

Abstract: Hydroxyapatite (HA) is a representative bone repairing biomaterial for its similar composition to human bones and teeth. However, pure HA is limited in application for some unwanted characteristic, such as it is brickle and weakness in degradation. In this study, we modified HA by doping magnesium (Mg) to the material and studied its property in vitro. Besides, we also evaluated the calvarial defect repair effect using MgHA combined with rhBMP-2 in goat model. According to our outcomes, HA composited Mg made the scaffold smooth and the pore regular. In vitro study, Mg could increase the Ca releasing, which may reflect a faster degradation property modified by Mg. And then, MgHA improved the cell viability and proliferation. Furthermore, MgHA could increase the expression of ALP, Collagen I and VEGF protein compared with pure HA (p<0.5, respectively). In the vivo study, MgHA showed a better bone defect healing effect in computed tomography (CT) evaluation compared with HA (p<0.05), but it was inferior to the MgHA/rhBMP-2 (p<0.05). Besides, in the histological analysis, MgHA/rhBMP-2 showed the most effective bone formation outcome (p<0.05), and the MgHA group was significant better than the pure HA group on osteogenesis (p<0.05). Furthermore, Collagen I and VEGF mRNA expression at 12 week in MgHA/rhBMP-2 group were also significat higher than other two groups. In conclusion, Mg had effects on bone formation and angiogenesis, and MgHA/rhBMP-2 had improved the bone defect repair effect. It is worthy of being recommended to bone tissue engineering.

Keywords: Bone defect repair, magnesium, hydroxyapatite, recombinant human bone morphogenetic protein-2

DOI: 10.3233/BME-171678

Journal: Bio-Medical Materials and Engineering, vol. 28, no. 4, pp. 361-377, 2017