Novel perfusion bioreactor for accelerated tissue engineered vascular wall histogenesis using additional longitudinal stretch of a tubular construct

The most important mechanical element of embryonic vascular development is longitudinal strain associated with arterial longitudinal growth. The increased use of stem cells as a cellular source in cardiovascular tissue engineering is transforming this field into an in vitro approach that seeks to accelerate recapitulation of in vivo embryonic vascular development. Thus, in order to "biomimic" the embryonic mechanical vascular environment (EMVE), the perfusion bioreactor must include the functional capacity for longitudinal strain. To accomplish this, a new perfusion bioreactor was developed to provide the simulation of the EMVE, and also investigate the impact of longitudinal strain on the cardiovascular engineered tubular construct (CETC) on acceleration of tissue engineered vascular wall histogenesis. The bioreactor includes two media perfusion systems: one for the inside and one for the outside perfusion of the CETC, and a third system, which controls the biomechanical properties of the CETC. A watertight chamber has a mechanism, which allows periodical changing of a longitudinal strain of the construct during the mechanical conditioning of the construct. The range of the longitudinal strain is 0% to 300%. The system that controls the biomechanical properties of the CETC includes a pressure transducer and a digital TV camera. Both controls are connected to the computer. This system allows the recording of a relationship between the radius of the CETC and pressure in static and dynamic regimes. Results indicate this new bioreactor can provide new critical components of biomechanical conditioning, which is essential to mimic EMVE and accelerate vascular wall histogenesis.