In vitro and in vivo evaluation of akermanite bioceramics for bone regeneration.
ABSTRACT This study investigated the effects of a calcium magnesium silicate bioceramic (akermanite) for bone regeneration in vitro and in vivo, with beta-tricalcium phosphate (beta-TCP) as a control. In vitro, the human bone marrow-derived mesenchymal stromal cells (hBMSCs) were cultured in an osteogenic medium supplemented with a certain concentration of two bioceramics' extracts for 20 days. An MTT assay showed that akermanite extract promoted proliferation of hBMSC significantly more than did beta-TCP extract. The results of alkaline phosphatase (ALP) activity test and the expression of osteogenic marker genes such as ALP, osteopontin (OPN), osteocalcin (OCN) and bone sialoprotein (BSP) demonstrated that the osteogenic differentiation of hBMSC was enhanced more by akermanite extract than by beta-TCP extract. In vivo, a histomorphology analysis and histomorphometry of the two porous bioceramics implants in rabbit femur defect models indicated that both in early- and late-stage implantations, akermanite promoted more osteogenesis and biodegradation than did beta-TCP; and in late-stage implantations, the rate of new bone formation was faster in akermanite than in beta-TCP. These results suggest that akermanite might be a potential and attractive bioceramic for tissue engineering.
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ABSTRACT: Two common methods have been used to evaluate the in vitro bioactivity of bioceramics for the application of bone repair. One is to evaluate the ability of apatite formation by soaking ceramics in simulated body fluids (SBF); the other method is to evaluate the effect of ceramics on osteogenic differentiation using cell experiments. Both methods have their own drawbacks in evaluating the in vitro bioactivity of bioceramics. In this commentary paper we review the application of both methods in bioactivity of bioceramics and conclude that (i) SBF method is an efficient method to investigate the in vitro bioactivity of silicate-based bioceramics, (ii) cellular bioactivity of bioceramics should be investigated by evaluating their stimulatory ability using standard bioceramics as controls; and (iii) the combination of these two methods to evaluate the in vitro bioactivity of bioceramics can improve the screening efficiency for the selection of bioactive ceramics for bone regeneration.
Article: Combustion Synthesis and Photoluminescence Characteristics of Akermanite: A Novel Biomaterial[show abstract] [hide abstract]
ABSTRACT: Silicate based bioceramics are the promising candidates as biomaterials for tissue engineering. The combustion synthesis method provides the control on the morphology and the particle size of the synthesised material. This paper discusses the combustion synthesis of Akermanite (Ca 2 MgSi 2 O 7 and Sr 2 MgSi 2 O 7), which has been shown to have good In vitro and in vivo bioactivity by the earlier studies. Both Ca 2 MgSi 2 O 7 and Sr 2 MgSi 2 O 7 have akermanite structure. Ca 2 MgSi 2 O 7 and Sr 2 MgSi 2 O 7 were prepared using urea and ammonium nitrate. The combustion synthesis using Urea and Ammonium Nitrate was found to be cost effective and efficient method of synthesis. The photoluminescence study of Ca 2 MgSi 2 O 7 : Eu 2+ and Sr 2 MgSi 2 O 7 : Eu 2+ shows host specific intense emission of Eu 2+.