Combination of Selective Etching and Impregnation toward Hollow Mesoporous Bioactive Glass Nanoparticles

Abstract

In this study, binary SiO2-CaO hollow mesoporous bioactive glass nanoparticles (HMBGNs) are prepared by combing selective etching and impregnation strategies. Spherical silica particles (SiO2 NPs) are used as hard cores to assemble cetyltrimethylammonium bromide (CTAB)/silica shells, which are later removed by selective etching to generate a hollow structure. After the removal of CTAB by calcination, the mesoporous shell of particles is formed. Calcium (Ca) is incorporated into the particles using impregnation by soaking the etched SiO2 NPs in calcium nitrate aqueous solution. The amount of incorporated Ca is tailorable by controlling the ratio of SiO2 NPs:calcium nitrate in the soaking solution. The produced HMBGNs are bioactive, as indicated by the rapid formation of hydroxyapatite on their surfaces after immersion in simulated body fluid. In a direct culture with MC3T3-E1 cells, HMBGNs were shown to exhibit concentration-dependent cytotoxicity and can stimulate osteogenic differentiation of MC3T3-E1 cells at concentrations of 1, 0.5, and 0.25 mg/mL. Our results indicate that the combination of selective etching and impregnation is a feasible approach to produce hierarchical HMBGNs. The produced hollow particles have potential in drug delivery and bone tissue regeneration applications, and should be further investigated in detailed in vitro and in vivo studies.

Bio‐Inspired Synthesis of Hollow Mesoporous Bioactive Glass Nanoparticles Using Calcium Carbonate as Solid Template

“…Due to the latter, it has been considered as a third generation biomaterial with immense importance in both soft and hard tissue repair and regeneration [11–13] . Hollow mesoporous bioactive glass nanoparticles have been formerly synthesized through individual or combination of templates under sol‐gel conditions [2–6,8–10] . Previous studies indicate CTAB alone [3,9,10,14] or in combination with block copolymers [5] to be effective template for generating hollow and mesoporous bioactive glass nanospheres.…”

“…Further, use of co‐templates for inducing mesoporous shell has been reported in addition to core‐forming template. In a recent study by Bocaccini et al , [8] in order to overcome the limitations of soft templates, solid silica spheres have been utilized as hard templates for synthesis of hollow mesoporous bioactive glass. The solid template provides control over size and dispersion to hollow bioactive glass nanoparticles.…”

“…Mesoporous and hollow bioactive glass nanoparticles are being currently explored owing to the advantages it provides in terms of higher drug loading capacity, biocompatibility and formation of hydroxyapatite when in presence of biological solutions. [1][2][3][4][5][6][7][8][9][10] Due to the latter, it has been considered as a third generation biomaterial with immense importance in both soft and hard tissue repair and regeneration. [11][12][13] Hollow mesoporous bioactive glass nanoparticles have been formerly synthesized through individual or combination of templates under sol-gel conditions.…”

“…[11][12][13] Hollow mesoporous bioactive glass nanoparticles have been formerly synthesized through individual or combination of templates under sol-gel conditions. [2][3][4][5][6][8][9][10] Previous studies indicate CTAB alone [3,9,10,14] or in combination with block copolymers [5] to be effective template for generating hollow and mesoporous bioactive glass nanospheres. Further, use of co-templates for inducing mesoporous shell has been reported in addition to core-forming template.…”

Nanoparticles for Bio-Medical Applications

“…These nanoparticles showed an absence of toxicity on MC3T3-E1 cells and lay the foundations for further applications in bone regeneration, tooth implants, and drug delivery. Mutlu et al prepared SiO 2 -CaO hollow mesoporous bioactive glass nanoparticles for bone applications using a combination of etching and impregnation strategies [ 4 ]. The authors demonstrated that differentiation of MC3T3-E1 cells occurs after incubation with these nanoparticles, showing their effectiveness in bone regeneration.…”