title: Role of magnesium oxide and strontium oxide as modifiers in silicate-based bioactive glasses: Effects on thermal behaviour, mechanical properties and in-vitro bioactivity.
abstract: The composition of a CaO-rich silicate bioglass (BG_Ca-Mix, in mol%: 2.3 Na2O; 2.3 K2O; 45.6 CaO; 2.6 P2O5; 47.2 SiO2) was modified by replacing a fixed 10mol% of CaO with MgO or SrO or fifty-fifty MgO-SrO. The thermal behaviour of the modified glasses was accurately evaluated via differential thermal analysis (DTA), heating microscopy and direct sintering tests. The presence of MgO and/or SrO didn't interfere with the thermal stability of the parent glass, since all the new glasses remained completely amorphous after sintering (treatment performed at 753°C for the glass with MgO; at 750°C with SrO; at 759°C with MgO and SrO). The sintered samples achieved good mechanical properties, with a Young's modulus ranging between 57.9±6.7 for the MgO-SrO modified composition and 112.6±8.0GPa for the MgO-modified one. If immersed in a simulated body fluid (SBF), the modified glasses after sintering retained the strong apatite forming ability of the parent glass, in spite of the presence of MgO and/or SrO. Moreover, the sintered glasses, tested with MLO-Y4 osteocytes by means of a multi-parametrical approach, showed a good bioactivity in vitro, since neither the glasses nor their extracts caused any negative effect on cell viability or any inhibition on cell growth. The best results were achieved by the MgO-modified glasses, both BGMIX_Mg and BGMIX_MgSr, which were able to exert a strong stimulating effect on the cell growth, thus confirming the beneficial effect of MgO on the glass bioactivity.
authors.affiliation: Department of Engineering "E. Ferrari", University of Modena and Reggio Emilia, Via P. Vivarelli 10, 41125 Modena, Italy. Electronic address: devis.bellucci@unimore.it.
authors.forename: Devis
authors.initials: D
authors.lastname: Bellucci
authors.affiliation: Department of Engineering "E. Ferrari", University of Modena and Reggio Emilia, Via P. Vivarelli 10, 41125 Modena, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Sola
authors.affiliation: Lab. Biomaterials, Department of Medical and Surgical Sciences of Children & Adults, University of Modena and Reggio Emilia, Via Campi 213/A, 41125 Modena, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Salvatori
authors.affiliation: Lab. Biomaterials, Department of Medical and Surgical Sciences of Children & Adults, University of Modena and Reggio Emilia, Via Campi 213/A, 41125 Modena, Italy.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Anesi
authors.affiliation: Lab. Biomaterials, Department of Medical and Surgical Sciences of Children & Adults, University of Modena and Reggio Emilia, Via Campi 213/A, 41125 Modena, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Chiarini
authors.affiliation: Department of Engineering "E. Ferrari", University of Modena and Reggio Emilia, Via P. Vivarelli 10, 41125 Modena, Italy.
authors.forename: Valeria
authors.initials: V
authors.lastname: Cannillo
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000633:toxicity; D017610:Calcium Compounds / Q000737:chemistry; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002516:Ceramics / Q000737:chemistry*; D006358:Hot Temperature; D008277:Magnesium Oxide / Q000737:chemistry*; D051379:Mice; D010087:Oxides / Q000737:chemistry; D017640:Silicates / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013324:Strontium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; C022107:Bioglass; D017610:Calcium Compounds; D010087:Oxides; D017640:Silicates; D008277:Magnesium Oxide; C016538:lime; D013324:Strontium
keywords: Bioactive glass; Bioactivity; Bone regeneration; Cell culture; Magnesium oxide; Strontium oxide