Osteoblastic and anti-osteoclastic activities of strontium-substituted silicocarnotite ceramics: In vitro and <i>in vivo</i> studies.

Zeng, Junkai; Guo, Jingshu; Sun, Zhenyu; Deng, Fanyan; Ning, Congqin; Xie, Youzhuan · Bioact Mater · 2020

basic_science · Level V

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Abstract

Osteoporosis bone defect is a refractory orthopaedic disease which characterized by impaired bone quality and bone regeneration capacity. Current therapies, including antiosteoporosis drugs and artificial bone grafts, are not always satisfactory. Herein, a strontium-substituted calcium phosphate silicate bioactive ceramic (Sr-CPS) was fabricated. In the present study, the extracts of Sr-CPS were prepared for <i>in vitro</i> study and Sr-CPS scaffolds were used for <i>in vivo</i> study. The cytocompatibility, osteogenic and osteoclastogenic properties of Sr-CPS extracts were characterized in comparison to CPS. Molecular mechanisms were also evaluated by Western blot. Sr-CPS extracts were found to promote osteogenesis by upregulating Wnt/β-catenin signal pathways and inhibit osteoclastogenesis through downregulating NF-κB signal pathway. <i>In vivo,</i> micro-CT, histological and histomorphometric observation were conducted after 8 weeks of implantation to evaluate the bone formation using calvarial defects model in ovariectomized rats. Compared with CPS, Sr-CPS significantly promoted critical sized ovariectomy (OVX) calvarial defects healing. Among all the samples, Sr-10 showed the best performance due to a perfect match of bone formation and scaffold degradation rates. Overall, the present study demonstrated that Sr-CPS ceramic can dually modulate both bone formation and resorption, which might be a promising candidate for the reconstruction of osteoporotic bone defect.