In vitro Evaluation of Porous borosilicate, borophosphate and phosphate Bioactive Glasses Scaffolds fabricated using Foaming Agent for Bone Regeneration

Abstract

In this work, glasses within the borosilicate borophosphate and phosphate family were sintered into 3D porous scaffolds using 60 and 70 vol. % NH4(HCO3) as a foaming agent. All scaffolds produced remained amorphous; apart from one third of the glasses which crystallized. All produced scaffolds had porosity >50% and interconnected pores in the range of 250–570 µm; as evidenced by µCT. The in-vitro dissolution of the scaffolds in SBF and changes in compression were assessed as a function of immersion time. The pH of the solution containing the borosilicate scaffolds increased due to the typical non-congruent dissolution of this glass family. Borophosphate and phosphate scaffolds induced a decrease in pH upon dissolution attributed to the congruent dissolution of those materials and the large release of phosphate within the media. As prepared, scaffolds showed compressive strength of 1.29 ± 0.21, 1.56 ± 0.63, 3.63 ± 0.69 MPa for the borosilicate, borophosphate and phosphate samples sintered with 60 vol. % NH4 (HCO3), respectively. Evidence of hydroxyapatite precipitation on the borosilicate glass scaffolds was shown by SEM/EDS, XRD and ICP-OES analysis. The borophosphate scaffolds remained stable upon dissolution. The phosphate scaffolds were fully crystallized, leading to very large release of phosphate in the media.

<p>Gadolinium-doped bioglass scaffolds promote osteogenic differentiation of hBMSC via the Akt/GSK3&beta; pathway and facilitate bone repair in vivo</p>

“…[2][3][4][5][6] Numerous studies have revealed that hierarchically porous characteristics and bioactive components could effectively regulate cellular performances such as attachment, migration, proliferation, and differentiation. [10][11][12][13][14][15] In particular, Gd element is found in human bones and plays a key role in bone tissue growth and regeneration. [19][20][21][22] In this study, we successfully fabricated Gd-BG scaffolds with hierarchical pores and bioactive Gd element for effective bone defect healing.…”

“…Mesoporous BGs have thus far been widely studied for bone regeneration. 11,12 The mesopores could increase ion exchange with the surrounding fluids in human bodies, mainly of Ca 2+ by H + . 16 The dissolution products of BGs, including Ca, Si, and P elements, have an upregulation effect on pro-osteoblastic genes.…”

“…9,10 In addition, the hierarchically porous characteristics of BG scaffolds play a pivotal role in bone regeneration performances. 11,12 The interconnected macroporous architecture facilitates the attachment of cells, diffusion of nutrients, and in-growth of blood vessels and newly formed bones. 11 The mesopores not only provide more active sites for protein adsorption and bone-like apatite formation, but also are useful for drug-delivery application.…”

“…11,12 The interconnected macroporous architecture facilitates the attachment of cells, diffusion of nutrients, and in-growth of blood vessels and newly formed bones. 11 The mesopores not only provide more active sites for protein adsorption and bone-like apatite formation, but also are useful for drug-delivery application. 12,13 In particular, BG microspheres that combine hollow cores with mesoporous shells provide the hierarchically porous microenvironment for tissue regeneration.…”

Novel borosilicate bioactive scaffolds with persistent luminescence

“…Finally, the scaffold should have a porous three-dimensional (3D) architecture with interconnected pore structure [9]. Recently, it was found that borosilicate glass can be sintered into 3D porous scaffolds allowing good bioactivity [11,12]. However, these scaffolds do not exhibit spectroscopic properties to allow one to track in-vivo the bioresponse of the scaffold.…”