Proangiogenic Potential of a Collagen/Bioactive Glass Substrate

Abstract

These studies suggest that this bioactive glass possesses a robust proangiogenic potential, and this strategy may provide an alternative to recombinant inductive growth factors.

Bioactive glass and glass-ceramic scaffolds for bone tissue engineering

“…For example, it has been demonstrated that dissolution products from bioactive glasses up-regulate the expression of genes that control osteogenesis [7,51], which explains the higher rate of bone formation in comparison to other inorganic ceramics such as hydroxyapatite [52]. Further studies using 45S5 Bioglass ® particles have shown encouraging results regarding potential angiogenic effects of Bioglass ® , i.e., increased secretion of vascular endothelial growth factor (VEGF) and VEGF gene expression in vitro, as well as enhancement of vascularization in vivo [53][54][55][56] (see §4). In addition, the incorporation of particular ions into the silicate network, such as silver [20][21][22] and boron [26,27], has been investigated in order 6 to develop antibacterial and antimicrobial materials.…”

“…After two weeks of implantation, histological analyses of calvaria demonstrated significantly greater neo-vascularisation and vascular density within defects treated with 45S5 BG (35 ± 16 vessels/mm 2 ) than with collagen controls alone (12 ± 2 vessels/mm 2 ) ( Figure 17). The angiogenic effect of bioactive glass was, however, much more pronounced in bioactive glass-based scaffolds (i.e., loaded sponges [56], discs [208], meshes [203], tubes [209] and porous glass-ceramics scaffolds [52,121,122]) than in composite structures incorporating and fully embedding bioactive glass particles (e.g., microsphere composites [164], or foams [55,210]). However, in vivo results so far are inconsistent with in vitro results, and provide an incomplete picture concerning the suggested angiogenic potential.…”

45S5-Bioglass®-Based 3D-Scaffolds Seeded with Human Adipose Tissue-Derived Stem Cells Induce In Vivo Vascularization in the CAM Angiogenesis Assay

“…For a plain biofunctionalization of the scaffold materials, we referred to a previously published technique, 32 where cell adhesion on the polypropylene meshes could be clearly enhanced by coating them before seeding with collagen containing extracellular matrix-like coating. Leu and Leach, 13 as well as Yao et al 37 already showed that collagen does not produce false-positive angiogenic side effects: Sponges made of collagen type-1 improved neither endothelial cell proliferation, HUVEC tube formation or an upregulation of VEGF production in coculture experiments in vitro 13 nor an ingrowth of blood vessels in the CAM angiogenesis assay in vivo.…”

“…[6][7][8][9] More recently, studies have shown that bioactive glasses may also be effective in promoting the vascularization of tissue constructs in different combinations, for example, as sintered scaffolds and composites. [10][11][12][13][14][15][16][17] The use of Bioglass Ò to fabricate scaffolds using a foam replica method was introduced in 2006 followed by studies on the possible angiogenic effect of such scaffolds. 18 Similar bioactive glass scaffolds were investigated in coculture studies using human umbilical vein endothelial cells (HUVEC) and human osteoblasts, 14 and it was shown that the scaffolds were able to support both endothelial and human osteoblast proliferation.…”

Structure and biological activity of glasses and ceramics

“…As is well known, they can bond to both bone and soft tissue, and the extent of the bioactivity can be controlled through adjusting the composition. They have recently been found to show proangiogenic tendencies [24][25][26][27][28], further promoting their use in tissue engineering. They are also resorbable, because the glass structure is fragmented and gradually dissolves during the process of forming an amorphous calcium phosphate layer and afterwards.…”