Human endothelial colony-forming cells expanded with an improved protocol are a useful endothelial cell source for...

Area of Science:

• Biomaterials Science
• Cell Biology
• Regenerative Medicine

Background:

• Tissue engineering faces challenges in vascularizing large 3D constructs, necessitating nutrient and oxygen supply and waste removal.
• Endothelial cells are crucial for initiating new blood vessel formation on scaffolds, but obtaining sufficient quantities is a bottleneck.
• Existing methods for endothelial cell expansion often compromise their functionality for tissue engineering applications.

Purpose of the Study:

• To investigate the potential of umbilical cord blood (CB)-derived endothelial colony-forming cells (ECFCs) as a cell source for tissue engineering.
• To develop and optimize a Good Manufacturing Practice (GMP)-compatible protocol for expanding ECFCs.
• To assess the viability, proliferation, and vascularization capacity of ex vivo-expanded ECFCs on biomaterial scaffolds.

Main Methods:

• ECFCs were isolated from umbilical cord blood.
• Marginal expansion of ECFCs was performed and their settlement on biomaterial scaffolds was assessed.
• A GMP-compatible expansion protocol was developed using human platelet lysates and novel tissue-culture ware, replacing animal sera.
• Apoptosis, proliferation, and viability rates of ECFCs cultured under new conditions were analyzed.
• The ability of extensively expanded ECFCs to form tubular structures in Matrigel assays and their settlement on scaffolds was evaluated.

Main Results:

• Marginally expanded ECFCs demonstrated successful settlement and survival on various scaffold biomaterials.
• The novel GMP-compatible culture conditions significantly reduced ECFC apoptosis and increased proliferation and viability rates.
• Ex vivo-expanded ECFCs retained their ability to settle on scaffolds and form tubular structures, indicating preserved vascularization potential.
• The developed protocol provides a scalable method for generating functional ECFCs.

Conclusions:

• Ex vivo-expanded ECFCs, cultured under GMP-compatible conditions, represent a highly effective cell source for scaffold-based tissue engineering.
• The optimized protocol overcomes the limitations of traditional endothelial cell sourcing and expansion.
• These findings pave the way for improved vascularization strategies in large-scale tissue engineering applications.