Design of vascular graft bioreactors

Abstract

The overall aim of vascular bioreactor design and operation is the use of a perfusion system to allow adhesion, growth and proliferation of vascular cells under in vitro conditions that emulate the in vivo physiological environment. There are three key factors to be considered: design of a bioreactor that allows the uniform in situ seeding of specific cells to the required scaffold surfaces; use of an appropriate system to generate mechanical forces and transmit them to the cells in the bioreactor; creation of an bioreactor infrastructure to allow long-term, aseptic culture and monitoring of human primary or stem cells and the developing tissue. Due to its relative infancy, literature describing the development of vascular bioreactors is limited with little in the way of standardized design. Such reports describe in some detail the perfusion circuits that incorporate the bioreactors, though few describe the vascular bioreactors in detail. Researchers are using unique, non-standardized systems, drawing on what little information is available. A drawback of this lack of standardisation is the inability to draw common conclusions from the different studies because of the design variation. Given that the mechanical environment is a strong determinant of gene expression, differences in design will effect gene expression and thus the performance of the graft as a whole. Clearly there is a need to define the underpinning design parameters and flow characteristics in order to facilitate comparative studies to improve design and integration methodologies. © 2005 Springer.