Incorporation of mesoporous glass particles in a resorbable glass fibrous scaffolds: a strategy to improve its bioactivity

Porous 3-D scaffolds are proposed as an alternative to the use of bone grafting technique in the situations of not-sufficient spontaneous bone regeneration. In this work, resorbable phosphate fibres and bioactive mesoporous particles (i.e. specific surface area up to 800 m2/g, adjustable pore size between 2 and 50 nm, large pore volume [1]) with different morphology and size were selected to combine the resorption property of the fibres with bioactive property of the powders. TiO2-containing phosphate glass (TiPS2.5) fibres (diameter of 110 m) were fabricated following the preform drawing technique, using a drawing tower, as described elsewhere [2]. A dense silica-based bioactive glass (CEL2) [3] was produced by melt quenching as reference sample. Spherical micro-sized mesoporous glass particles based on SiO2-CaO system (SD_MBG) were produced combining sol-gel method with the aerosol-assisted spray-drying technique [4]. Cu-containing (85SiO2-13CaO-2CuO, % mol, referred as Cu_BGn2%) mesoporous glass nanoparticles, with antibacterial properties, were synthetized by an ultra-sound assisted sol-gel method. To produce the fibrous scaffolds, the selected powder and phosphate glass fibres cut at precise length were placed in a beaker containing 2 ml of ethanol. After ethanol evaporation, the powder/fibre mixture was then randomly placed inside a zirconia cylindrical mould. After the thermal treatment, scaffolds were analyzed with micro-CT in order to investigate their inner structure. By soaking them in SBF, their ability to form hydroxyapatite was investigated. Scaffolds morphology before and after immersion in SBF was studied by FESEM.