fabrication-engineered-vascular-flaps-using-3d-printing

Fabrication of Engineered Vascular Flaps Using 3D Printing Technologies

Engineering implantable, functional, thick tissues requires designing a hierarchical vascular network. 3D bioprinting is a technology used to create ...

Technion-Israel Institute of Technology

Engineering hierarchical vasculatures is critical for creating implantable functional thick tissues. Current approaches focus on fabricating mesoscale vessels for implantation or hierarchical microvascular in vitro models, but a combined approach is yet to be achieved to create engineered tissue flaps. Here, millimetric vessel-like scaffolds and 3D bioprinted vascularized tissues interconnect, creating fully engineered hierarchical vascular constructs for implantation. Endothelial and support cells spontaneously form microvascular networks in bioprinted tissues using a human collagen bioink. Sacrificial molds are used to create polymeric vessel-like scaffolds and endothelial cells seeded in their lumen form native-like endothelia. Assembling endothelialized scaffolds within vascularizing hydrogels incites the bioprinted vasculature and endothelium to cooperatively create vessels, enabling tissue perfusion through the scaffold lumen. Using a cuffing microsurgery approach, the engineered tissue is directly anastomosed with a rat femoral artery, promoting a rich host vasculature within the implanted tissue. After two weeks in vivo, contrast microcomputer tomography imaging and lectin perfusion of explanted engineered tissues verify the host ingrowth vasculature's functionality. Furthermore, the hierarchical vessel network (VesselNet) supports in vitro functionality of cardiomyocytes. Finally, the proposed approach is expanded to mimic complex structures with native-like millimetric vessels. This work presents a novel strategy aiming to create fully-engineered patient-specific thick tissue flaps.

3D Bioprinting of Engineered Tissue Flaps with Hierarchical Vessel Networks (VesselNet) for Direct Host-To-Implant Perfusion.

Microtia is a small, malformed external ear, which occurs at an incidence of 1-10 per 10 000 births. Autologous reconstruction using costal cartilage is the most widely accepted surgical microtia repair technique. Yet, the method involves donor-site pain and discomfort and relies on the artistic skill of the surgeon to create an aesthetic ear. This study employed novel tissue engineering techniques to overcome these limitations by developing a clinical-grade, 3D-printed biodegradable auricle scaffold that formed stable, custom-made neocartilage implants. The unique scaffold design combined strategically reinforced areas to maintain the complex topography of the outer ear and micropores to allow cell adhesion for the effective production of stable cartilage. The auricle construct was computed tomography (CT) scan-based composed of a 3D-printed clinical-grade polycaprolactone scaffold loaded with patient-derived chondrocytes produced from either auricular cartilage or costal cartilage biopsies combined with adipose-derived mesenchymal stem cells. Cartilage formation was measured within the construct, and cartilage maturation and stabilization were observed 12 weeks after its subcutaneous implantation into a murine model. The proposed technology is simple and effective and is expected to improve aesthetic outcomes and reduce patient discomfort.

Human-engineered auricular reconstruction (hEAR) by 3D-printed molding with human-derived auricular and costal chondrocytes and adipose-derived mesenchymal stem cells.

Article	Year
3D Bioprinting of Engineered Tissue Flaps with Hierarchical Vessel Networks (VesselNet) for Direct Host-To-Implant Perfusion. Advanced materials (Deerfield Beach, Fla.)\| PubMed ID: 34510579	2021
Human-engineered auricular reconstruction (hEAR) by 3D-printed molding with human-derived auricular and costal chondrocytes and adipose-derived mesenchymal stem cells. Biofabrication\| PubMed ID: 34798628	2021

Majd Machour

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