Multicellularity, Culture Duration, and Hydrogel Stiffness Guide Induced Pluripotent Stem Cell-Derived Endothelial...

Area of Science:

• Biomaterials Science
• Stem Cell Biology
• Regenerative Medicine

Background:

• Human induced pluripotent stem cells (hiPSCs) are a promising source for patient-specific cell generation.
• Vascularization remains a significant challenge for hiPSC-derived tissues in therapeutic applications and disease modeling.
• hiPSC-derived endothelial progenitor cells (hiPSC-EPs) can self-assemble into microvascular networks in 3D hydrogels.

Purpose of the Study:

• To investigate the early contractility of hiPSC-EPs within hydrogels.
• To determine how multicellularity, culture duration, and hydrogel stiffness influence hiPSC-EP contractility.
• To understand the mechanical interactions governing hiPSC-EP self-assembly into vascular networks.

Main Methods:

• 3D kinematic analysis of hiPSC-EPs encapsulated in norbornene-functionalized hyaluronic acid (NorHA) hydrogels.
• Quantification of cellular contractility at 4 and 7 days post-encapsulation.
• Modified kinematic analysis to account for hydrogel compressibility, incorporating deviatoric and volumetric strain indices.

Main Results:

• hiPSC-EP contractility was significantly and non-linearly influenced by multicellularity, culture duration, and hydrogel stiffness.
• NorHA hydrogels exhibited compressible behavior, with lower stiffness gels being more compressible.
• By day 7, multicellularity synergistically enhanced both deviatoric and volumetric strain components.

Conclusions:

• hiPSC-EP contractility and mechanical interactions are governed by culture duration, multicellularity, and hydrogel stiffness.
• These findings provide critical mechanical insights into hiPSC-EP self-assembly into microvasculature networks.
• Understanding these mechanical factors is essential for developing functional vascular tissues for regenerative medicine.