Dosage and composition of bioactive glasses differentially regulate angiogenic and osteogenic response of human MSCs

Abstract

Vascularization of the fracture site and cell-mediated deposition of the mineralized matrix are crucial determinants for successful bone regeneration after injury. Ceramic biomaterials such as bioactive glasses (BAGs) that release bioactive ions have shown promising results in bone defect regeneration. However, it remains unclear how the dosage and composition of bioactive ions influence the angiogenic and osteogenic behavior of primary human mesenchymal stromal cells (MSCs). Here, we show that exposure to ionic dissolution products from 1393 and 45S5 BAGs can evoke distinct angiogenic and osteogenic responses from primary MSCs in a dose-and composition-dependent manner. Significantly higher concentrations of the pro-angiogenic factors VEGF, HGF, PIGF, angiopoietin, and angiogenin were detected in conditioned media (CM) from MSCs exposed to 45S5, but not 1393, BAGs. Application of this CM to human umbilical vein endothelial cells (HUVECs) resulted in robust 2D tube formation in vitro. Osteogenic differentiation of MSCs was assessed by gene expression analysis and mineralization assays. Low concentrations (0.1% w/v) of 1393 BAGs significantly enhanced the gene expression of RUNX2 and ALP and induced an earlier onset of matrix mineralization compared to all other groups. We further tested whether simultaneous exposure to both BAGs would improve both angiogenic secretion and osteogenic differentiation of MSCs, and did not find evidence to support this hypothesis. Our results provide evidence of BAG composition-dependent enhancement of primary human MSCs' regenerative function, besides also underlining the importance of an in vitro evaluation of the dose-response relationship to translate BAG based approaches into safe and effective clinical therapies.

Primary osteoblasts, osteoblast precursor cells or osteoblast‐like cell lines: Which human cell types are (most) suitable for characterizing 45S5‐bioactive glass?

“…The group of Qazi et al evaluated the impact of 45S5-BG and 1393-BG on osteogenic differentiation of BMSCs and found an upregulation in osteogenic gene expression patterns induced by both BGs (Qazi et al, 2018). In a study conducted by our group, supplementation with 45S5-BG led to accelerated osteogenic differentiation and maturation of BMSCs compared to pure tricalciumphosphate scaffolds .…”

“…BMSCs are therefore suitable to assess the impact of materials, growth factors, differentiation factors, etc. The impact of BGs on viability (Qazi et al, 2017;Westhauser et al, 2019), proliferation (Qazi et al, 2017;Westhauser et al, 2019), and osteogenic differentiation (Qazi et al, 2018;Westhauser et al, 2019) has been assessed using As summarized in a review paper conducted by the group of Kargozar, they are suitable cell types for transplantation in in various organisms via seeded scaffolds, directly accelerating bone regeneration at site (Kargozar et al, 2019).…”

“…Since the cell lines used in the studies are derived from tumor tissue, they can only be compared to osteoblasts to a limited T A B L E 1 Human cells used for BTE protocols involving BGs, representative studies. (Qazi, Hafeez et al 2017;Qazi, Berkmann et al 2018;Westhauser, Karadjian et al 2019) MG-63 Cell line Osteosarcoma cells, derived from a 13-year-old male Caucasian patient (Billiau, Edy et al 1977;Czekanska, Stoddart et al 2012). Both, cell lines and primary cells are included (Gough, Clupper et al 2004;Huang, Jayasinghe et al 2005;Jones, Tsigkou et al 2007;Deb, Mandegaran et al 2010;Fan, Kalia et al 2014;Xynos et al, 2000;Xynos et al, 2001) BMSC Primary Bone marrow-derived mesenchymal stromal cell (BMSC), early osteoblast precursor.…”

“…Usually isolated by density-gradient centrifugation of bone marrow (Reible, Schmidmaier et al 2017;Reible, Schmidmaier et al 2018). (Qazi, Hafeez et al 2017;Qazi, Berkmann et al 2018;Westhauser, Karadjian et al 2019) MG-63 Cell line Osteosarcoma cells, derived from a 13-year-old male Caucasian patient (Billiau, Edy et al 1977;Czekanska, Stoddart et al 2012). (Price, Bendall et al 1997;Ferraz, Knowles et al 1999;Itala, Ylanen et al 2002;Vitale-Brovarone, Verne et al 2007;Lopes, Ferreira et al 2011;Wang, Falk et al 2011;Gong, Dong etal.…”

Bioactive Glass (BG) ICIE16 Shows Promising Osteogenic Properties Compared to Crystallized 45S5-BG

“…The release of therapeutically active ions from BGs exhibit a dose-dependent impact on osteogenic differentiation of bone precursor cells [5,6,18,24,30,31]. Ion release starts immediately after contact of the BGs to the surrounding liquid, in this case, CCM [7,29].…”