Promoting vascularization for tissue engineering constructs: current strategies focusing on HIF-regulating scaffolds

Area of Science:

• Tissue Engineering
• Biomaterials Science
• Angiogenesis Research

Background:

• Engineered tissues require vascularization for nutrient and oxygen supply, a major challenge in tissue engineering.
• Diffusion limits nutrient/oxygen transport in larger tissue constructs, necessitating perfusable vascular structures.
• Hypoxia-inducible factors (HIFs) are key regulators of adaptive responses to low oxygen, including blood vessel formation (angiogenesis).

Purpose of the Study:

• To review current strategies for vascularizing engineered tissues.
• To summarize knowledge on activating HIF signaling for angiogenesis.
• To focus on incorporating HIF-activating agents into biomaterials for controlled release.

Main Methods:

• Review of current vascularization strategies in tissue engineering.
• Summary of HIF signaling activation pathways (ions, iron chelators, αKG analogues, simvastatin).
• Discussion on incorporating HIF-activating agents into biomaterials and scaffolds.

Main Results:

• HIF activation is a promising strategy for inducing vascularization in engineered tissues.
• Various agents (ions, iron chelators, αKG analogues, simvastatin) can activate HIF signaling.
• Controlled release of HIF activators from biomaterials is a key focus.

Conclusions:

• HIF activation offers advantages for tissue vascularization but has limitations.
• The HIF-induced angiogenic program may be too slow for large constructs.
• Combining HIF activation with cell protection and prevascularization is crucial for viable, large-scale engineered tissues.