Abstract
The physiological O2 microenvironment of mesenchymal stem cells (MSCs) and osteoblasts and the dimensionality of a substrate are known to be important in regulating cell phenotype and function. By providing the physiologically normoxic environments of bone marrow (5%) and matrix (12%), we assessed their potential to maintain stemness, induce osteogenic differentiation, and enhance the material properties in the micropatterned collagen/silk fibroin scaffolds that were produced in 2D or 3D. Expression of osterix (OSX) and vascular endothelial growth factor A (VEGFA) was significantly enhanced in the 3D scaffold in all oxygen environments. At 21% O2, OSX and VEGFA expressions in the 3D scaffold were respectively 13,200 and 270 times higher than those of the 2D scaffold. Markers for assessing stemness were significantly more pronounced on tissue culture polystyrene and 2D scaffold incubated at 5% O2. At 21% O2, we measured significant increases in ultimate tensile strength (p < 0.0001) and Young’s modulus (p = 0.003) of the 3D scaffold compared to the 2D scaffold, whilst 5% O2 hindered the positive effect of cell seeding on tensile strength. In conclusion, we demonstrated that the 3D culture of MSCs in collagen/silk fibroin scaffolds provided biomimetic cues for bone progenitor cells toward differentiation and enhanced the tensile mechanical properties.
Highlights
Culturing cells in 3D is typically conducted at atmospheric O2, which is approximately 21% [1,2,3,4]
In in vivo tissues, including bone, the physiological O2 level is much lower between 5–14%, and resident cells respond to the changing O2 environment through the hypoxia inducible factor (HIF)-regulated O2-sensing mechanism [5]
These works on hypoxia do not include scaffolds that are proposed to be used for bone tissue engineering (TE) purposes, but they were about in vitro osteogenic differentiation of mesenchymal stem cells (MSCs) on tissue culture plate in the range of
Summary
Culturing cells in 3D is typically conducted at atmospheric O2, which is approximately 21% [1,2,3,4]. The bone matrix has ambient O2 tension of approximately 12% owing to arterial blood vasculature This 12% O2 level plays a role in maintaining osteoblast phenotype [6], as low O2 condition is associated with the stem cell niche and preservation of cells in an undifferentiated state [7]. Contrary to the majority of studies using 21% O2 to culture MSCs, fewer studies focus on utilizing hypoxia for bone cell culture These works on hypoxia do not include scaffolds that are proposed to be used for bone tissue engineering (TE) purposes, but they were about in vitro osteogenic differentiation of MSCs on tissue culture plate in the range of
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
