Functional tissue-engineered bone-like graft made of a fibrin scaffold and TG2 gene-modified EMSCs for bone defect repair

Abstract

The transplantation of tissue-engineered scaffolds with stem cells is a promising therapeutic approach for bone defect repair. To improve the therapeutic efficacy of this approach, in this study, a novel biofunctional live tissue-engineered bone-like graft was designed and constructed using a fibrin scaffold loaded with TG2 gene-modified ectomesenchymal stem cells (TG2-EMSCs) derived from nasal respiratory mucosa for bone defect repair. Autocalcification of the cell-free fibrin gel in osteogenic medium with additional alkaline phosphatase (ALP) and the osteogenic differentiation of TG2-EMSCs on the fibrin scaffold were assessed in vitro. The results indicated that the cell-free fibrin gel could autocalcify in the osteogenic medium with ALP and that the overexpression of TG2 by TG2-EMSCs could promote the osteogenic differentiation of these stem cells in the fibrin scaffold. Moreover, TG2 could enhance the deposition of extracellular matrix proteins in the fibrin scaffold, followed by calcification of the bone matrix in vitro. After transplantation into critical-sized cranial defects in rats, the functional tissue-engineered bone-like grafts improved bone regeneration. These results indicate that this tissue-engineered bone-like graft could improve the process of bone defect repair.

Periodic Heat Stress Licenses EMSCs Differentiation Into Osteoblasts via YAP Signaling Pathway Activation

“…TG2 has been identi ed as an important extracellular crosslinking enzyme involved in ECM turnover and bone differentiation [44]. As shown in our previous study, TG2 overexpression enhances the osteogenic differentiation of EMSCs, partially through crosslinking ECM and BMP-2 [6]. Using various cell lines, Fisher and Liu showed that TG2 is directly regulated by YAP [39,40]; by upregulating TG2 expression, YAP probably forms a positive feedback loop.…”

“…EMSCs were isolated from rats as described in our previous studies [6]. Brie y, two rats (50-80 g) were sacri ced by administering pentobarbital sodium (200 mg/kg).…”

“…Numerous studies examining the effects of growth factors or cytokines on MSC differentiation into osteoblasts have been performed [4,5]. Previous studies conducted in our laboratory have shown that the lamina propria of the mucosa lining the respiratory region of the nasal cavity contains ectomesenchymal stem cells (EMSCs) [6,7]. These cells have the potential to differentiate into a variety of cell types, including osteoblasts [8,9].…”

“…These cells have the potential to differentiate into a variety of cell types, including osteoblasts [8,9]. As shown in our recent study, an injection of ectomesenchymal stem cells (EMSCs) into the skull bone defect site contributes to bone defect repair [6]. However, osteoblasts that differentiated from MSCs are still not as functionally mature as primary adult cells.…”

Black Phosphorus Nanoparticles Promote Osteogenic Differentiation of EMSCs Through Upregulated TG2 Expression

“…Besides, EMSCs are self-renewable with multidirectional differentiation potential, which have been thoroughly characterized in our previous studies [ 16 , 17 ]. We have proved that EMSCs can differentiate into several cell lineages including adipocytes, neurocytes, chondrocytes and osteocytes [ 18 , 19 ]. These special properties render EMSCs as a promising tool for exploring potential molecular mechanisms that modulate the osteogenic differentiation of EMSCs by chemical signals, including BPs.…”