Vascularized Flaps as Living Bioreactors in Bone Tissue Engineering: From Biological Principles to Translational...

Area of Science:

• Regenerative Medicine
• Biomaterials Science
• Surgical Innovation

Background:

• Large segmental bone defects pose significant reconstructive challenges, especially with poor vascularization.
• Insufficient vascular supply is a primary limitation in bone tissue engineering, hindering osteogenesis and graft success.
• Current scaffold designs and biomaterials struggle to overcome vascularization deficits.

Purpose of the Study:

• To review the role of vascularized flaps as "living bioreactors" in bone tissue engineering.
• To analyze their capacity to improve scaffold vascularization and osteogenesis.
• To assess their potential for clinical translation in bone regeneration.

Main Methods:

• Conducted a narrative review of PubMed, Scopus, and Web of Science.
• Used keywords: "bone tissue engineering", "vascularized flaps", "arteriovenous loop", "in vivo bioreactor".
• Selected preclinical and clinical studies on scaffold vascularization strategies.

Main Results:

• Vascularized flaps provide essential vascular networks and microenvironments for scaffold integration and regeneration.
• Periosteal flaps show osteogenic potential; muscle/omental flaps serve as vascular carriers.
• Arteriovenous (AV) loop strategies and hybrid approaches like regenerative matching axial vascularization (RMAV) ensure rapid, homogeneous perfusion of large constructs.

Conclusions:

• Vascularization strategies are shifting bone tissue engineering towards actively engineered, vascularized constructs.
• Integrating microsurgical techniques with advanced biomaterials is key for personalized bone regeneration.
• These approaches hold significant promise for clinically applicable bone regeneration strategies.