Fabrication of lumenized vascular tubes for tissue engineering applications

Abstract

There is an ever-growing demand for donor organs in the world today which is unmet by the very limited supply. To address this shortage, tissue engineers aim to replace or restore damaged tissue in patients without the need for autologous/allogeneic tissue grafts from donor sites. Engineered tissue is fabricated in a lab using the patient's own cells and implanted into the site of injury after expansion and maturation. This approach to tissue repair eliminates the need for large donor tissue to treat large injuries. It could even be developed to engineer whole organs to replace a patient's entire damaged organ in the future. In order to engineer large tissue grafts or whole organs, vascular networks need to be incorporated into the tissue to prevent cell necrosis caused by insufficient access to nutrients. In this paper, a new method to fabricate lumenized, freestanding vascular tubes is proposed. Human Umbilical Vein Endothelial Cells (HUVECs) were encapsulated within Gelma fibers anchored onto glass cover slips and cultured. At day 3, live/dead staining was performed on encapsulated HUVECs and showed high cell viability. Encapsulated cells proliferated with time and at day 5, they connected with each other to form vascular tubes with clearly defined lumen as shown by confocal images of nuclei and actin staining. We believe that our fabricated vascular tubes will have applications in large 3D tissue engineering.