Engineering vessel-like networks within multicellular fibrin-based constructs.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Achieving sufficient vascularization is critical for engineered tissues.
• Biomaterial systems and cell types must be carefully selected to support vascular development.
• Existing methods often struggle to promote robust neovascularization.

Purpose of the Study:

• To evaluate the efficacy of 3D fibrin gels, alone or combined with synthetic scaffolds, for supporting in-vitro vascularization.
• To assess the potential of these constructs to enhance neovascularization upon implantation.
• To investigate the role of fibrinogen concentration and scaffold composition on vessel network formation.

Main Methods:

• Utilized 3D fibrin gels and poly(l-lactic acid)/poly(lactic-glycolic acid) (PLLA/PLGA) sponges as biomaterial platforms.
• Incorporated multicellular assays: co-culture of endothelial cells (ECs) and fibroblasts, and tri-culture with ECs, fibroblasts, and skeletal myoblasts.
• Examined in-vitro vessel network formation using confocal microscopy and assessed in-vivo neovascularization after implantation.

Main Results:

• In-vitro vessel network maturity and morphology were significantly influenced by fibrinogen concentration.
• The combination of PLLA/PLGA sponges with fibrin matrices enhanced mechanical strength and promoted mature vessel-like networks.
• Implanted ECs successfully formed 3D interconnected vessel-like networks in-vivo, with PLLA/PLGA scaffolds stimulating neovascularization and graft perfusion.

Conclusions:

• A complex biomaterial platform integrating fibrin and PLLA/PLGA synthetic scaffolds effectively enhances vascularization.
• This approach supports both in-vitro construct development and in-vivo neovascularization.
• The findings offer a promising strategy for improving vascular integration in tissue engineering.