ACTIVITIES
AM Webinars

Vascularization of an engineered patch fabricated using 3D printing technology

May 19, 2022
13:30
Vertual talk
Ariel Szklanny
|
CTO and Co-founder at Plantish

Abstract:

The main goal of tissue engineering is creating implantable organs and tissue substitutes for patients with a partial or total loss of organ functionality. A fundamental characteristic present in most tissues in the body is a rich vascular network that provides nourishment to tissue-forming cells. A lack of proper vascularization can lead to cell death and subsequent tissue necrosis. Thus, creating functional vascular networks in engineered tissues is a critical challenge in the field. In an adequate environment, vascular networks can spontaneously form when culturing together endothelial cells (ECs, which make the tubular structure) with support cells (SCs, which provide chemical and mechanical support). First, we sought to understand the vessels’ behavior in response to the surroundings’ geometry. For this, we created a novel high-throughput platform that allowed us to observe vessel sprouting and migration processes in real-time. We seeded ECs and SCs on scaffolds with four different compartment geometries and tracked the newly formed branching vessels migration. The migration patterns changed according to the compartment geometry, showing an increased movement towards concave areas of the scaffold.

With this in mind, we aimed to harness the versatility of 3D printing and bioprinting to create a mid-size synthetic vessel scaffold that could connect to self-assembled vascular networks, which are embedded in a natural environment; the formed construct is a tissue flap. We fabricated the polymeric vessel using a 3D printed sacrificial mold. Using a bioink (biological printable ink) formulation of recombinant human type 1 collagen methacrylate (rhCollMA), we bioprinted ECs and SCs and assembled the vessel inside the printed construct. After assembly, the vascular formation process started in the rhCollMA, shrinking the gel and creating a tight contact between the vessel and printed cells. ECs seeded in the vessel lumen created an endothelium-like configuration and communicated with the ECs in the surrounding gel. After in vitro culture, the prevascularized constructs were implanted and anastomosed with a rat host artery using microsurgery. This combination of synthetic and natural materials represents an exciting step towards achieving perfusable thick vascularized tissue flap.

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