Transient Support from Fibroblasts is Sufficient to Drive Functional Vascularization in Engineered Tissues

Area of Science:

• Biomedical Engineering
• Tissue Engineering
• Developmental Biology

Background:

• Capillary blood vessel formation is essential for organ development and function.
• Fibroblasts are known to support endothelial cell morphogenesis in vitro.
• The long-term necessity and removal strategies for fibroblasts in engineered vasculature are unclear.

Purpose of the Study:

• To investigate the temporal requirement of fibroblasts in endothelial cell morphogenesis.
• To introduce and validate a method for on-demand fibroblast ablation in engineered tissues.
• To assess the impact of fibroblast removal on vascular structure, function, and overall tissue performance.

Main Methods:

• Development of CAMEO (Controlled Apoptosis in Multicellular Tissues for Engineered Organogenesis) for selective fibroblast ablation.
• Co-culture of endothelial cells and fibroblasts to induce vascular morphogenesis.
• Assessment of vascular network development and function post-fibroblast ablation.
• Application of CAMEO in a hepatocyte-tissue construct to evaluate functional improvements.

Main Results:

• Fibroblasts are crucial only during the initial phase of endothelial cell morphogenesis.
• Selective ablation of fibroblasts using CAMEO did not compromise vascular structure or function.
• CAMEO-mediated vascularization of hepatocyte constructs enhanced tissue function.
• Transient fibroblast support is sufficient for engineered vascularization.

Conclusions:

• Fibroblast support for vascular morphogenesis in engineered tissues is transient and limited to the initial stages.
• The CAMEO technique enables controlled elimination of stromal cells, facilitating clinical translation of engineered organs.
• This engineering-via-elimination strategy offers a versatile approach for optimizing cell composition and function in engineered organs.