Sheet‐based Tissue Engineering: Autologous Blood Vessels and Beyond

Sheet‐Based Tissue Engineering (SBTE) is a method that allows the production of completely biological and living autologous tissues that have remarkable mechanical strength without the inclusion of any exogenous scaffolds. The introduction of this approach marks a paradigm shift away from the "off‐the‐shelf" approaches that have repeatedly failed in past, towards a more realistic approach where the patients own cells produce the basic organ structure in vitro. The first construct produced through SBTE is a small diameter blood vessel. In an initial clinical trial, blood vessels were produced for patients (age up to 89 y) suffering from end‐stage renal disease. Vessels displayed artery‐like burst pressures and satisfactory suture retention strength. Vessels were implanted in 10 patients with primary patency up to 22 months at time of submission. Ultrasound examinations demonstrated an increase in graft compliance to achieve physiological levels. Limited histological samples indicated a remodeling of the vessel wall with expression of smooth muscle cell markers. This study establishes for the first time that completely biological and autologous blood vessels produced in vitro have the potential for long‐term patency.