title: Mixture designs to assess composition-structure-property relationships in SiO₂-CaO-ZnO-La₂O₃-TiO₂-MgO-SrO-Na₂O glasses: potential materials for embolization.
abstract: Embolization with micron-sized particulates is widely applied to treat uterine fibroids. The objective of this work was to develop mixture designs to predict materials composition-structure-property relationships for the SiO₂-CaO-ZnO-La₂O₃-TiO₂-MgO-SrO-Na₂O glass system and compare its fundamental materials properties (density and cytocompatibility), against a state-of-the-art embolic agent (contour polyvinyl alcohol) to assess the potential of these materials for embolization therapies. The glass structures were evaluated using ²⁹Si MAS NMR to identify chemical shift and line width; the particulate densities were determined using helium pycnometry and the cell viabilities were assessed via MTT assay. ²⁹Si MAS NMR results indicated peak maxima for each glass in the range of -82.3 ppm to -89.9 ppm; associated with Q² to Q³ units in silicate glasses. All experimental embolic compositions showed enhanced in vitro compatibility in comparison to Contour PVA with the exceptions of ORP9 and ORP11 (containing no TiO₂). In this study, optimal compositions for cell viability were obtained for the following compositional ranges: 0.095-0.188 mole fraction ZnO; 0.068-0.159 mole fraction La₂O₃; 0.545-0.562 mole fraction SiO₂ and 0.042-0.050 mole fraction TiO₂. To ensure ease of producibility in obtaining good melts, a maximum loading of 0.068 mole fraction La₂O₃ is required. This is confirmed by the desirability approach, for which the only experimental composition (ORP5) of the materials evaluated was presented as an optimum composition; combining high cell viability with ease of production (0.188 mole fraction ZnO; 0.068 mole fraction La₂O₃; 0.562 mole fraction SiO₂ and 0.042 mole fraction TiO₂).
authors.affiliation: Department of Applied Oral Sciences, Dalhousie University, Halifax, NS, Canada. sharonkehoe@dal.ca
authors.forename: Sharon
authors.initials: S
authors.lastname: Kehoe
authors.forename: Maxine
authors.initials: M
authors.lastname: Langman
authors.forename: Ulli
authors.initials: U
authors.lastname: Werner-Zwanziger
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Abraham
authors.forename: Daniel
authors.initials: D
authors.lastname: Boyd
mesh_terms: D045424:Complex Mixtures; D004621:Embolization, Therapeutic; D005898:Glass; D010087:Oxides / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D045424:Complex Mixtures; D010087:Oxides