Innovative Approach of Organ Tissue Engineering Using Autologous Decellularized Microcirculatory Beds As Vascularized Bioscaffolds

Introduction:

Advances in tissue engineering are hampered by the inability of artificial scaffolds to recapitulate complex microvascular structures. However, functional microvascular beds exist throughout the body, they are explantable and readily re-integrated into the systemic circulation (i.e. microvascular free flaps). In the current study we utilize these explantable microvascular beds (EMBs) as scaffolds for progenitor cell seeding as a novel approach to organ-level tissue engineering.

Methods:

Superficial inferior epigastric artery flaps (SIEA) were harvested from Sprague-Dawley rats (n=10) and maintained on a perfusion bioreactor. After decellularization, EMBs were seeded with human adipose-derived stem cells (hASCs). hASC seeded-EMBs were microsurgically re-anastomosed into the femoral vessels of nude rats. Vascular integrity was confirmed using SEM and immunohistochemical staining for matrix-specific components. Cell viability and integration were followed using bioluminescent imaging.

Results:

SIEA/EMB tissue flaps were effectively decellularized and maintained on the bioreactor for over 24 hours. SEM and immunohistochemical staining for collagen IV and laminin confirmed vascular integrity. Seeding of hASCs onto EMBs was successfully achieved with perfusion methods. hASCs seeded onto EMBs demonstrated excellent viability and engraftment in vitro. Transplanted EMB/hASC constructs were viably sustained in vivo based on bioluminescence imaging and histology.

Conclusion:

Autologous vascular beds are ideal bioscaffolds that can be effectively decellularized and seeded with hASCs. Reintegration of seeded EMBs with longterm viability is feasible. Together, these successful studies suggest that progenitor cell-seeded vascularized scaffolds are a promising approach to fabricate complex organ-level constructs.