Hypoxia Created Human Mesenchymal Stem Cell Sheet for Prevascularized 3D Tissue Construction

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Stem Cell Biology

Background:

• 3D tissue constructs using human mesenchymal stem cell (hMSC) sheets show promise for connective tissue regeneration.
• Prevascularization with endothelial cells (ECs) is crucial for 3D tissue survival and host integration.
• Hypoxia is hypothesized to enhance microvessel formation and preserve hMSC stemness.

Purpose of the Study:

• To investigate the impact of different oxygen tensions on hMSC sheet vascularization.
• To evaluate the potential of hypoxia-primed hMSC sheets for creating 3D prevascularized tissue constructs.
• To assess the stemness and differentiation potential of hMSCs within the engineered constructs.

Main Methods:

• hMSC sheets were cultured under varying oxygen conditions (hypoxia and normoxia).
• hMSC sheets were co-cultured with ECs under normoxic conditions (HN condition).
• Vascular network formation, angiogenic factor levels, and hMSC stemness were analyzed.
• 3D constructs were fabricated by layering prevascularized hMSC sheets and matured in a rotating wall vessel bioreactor.

Main Results:

• The HN condition (hypoxia-formed hMSC sheets co-cultured with ECs under normoxia) resulted in more extensive and branched microvessel networks.
• Higher levels of angiogenic factors were detected in the co-culture medium under HN conditions.
• Hypoxic hMSC sheets were more uniform, facilitating the fabrication of defect-free 3D constructs.
• hMSCs within the 3D constructs retained their multilineage differentiation ability.

Conclusions:

• Hypoxia preconditioning of hMSC sheets enhances microvessel network development.
• The developed 3D prevascularized tissue constructs are feasible for connective tissue regeneration.
• This approach supports hMSC stemness and promotes vascularization, offering a promising strategy for tissue engineering.