Design of bioreactors for mesenchymal stem cell tissue engineering

There is a growing need for efficient mesenchymal stem cell (MSC) production processes for a wide spectrum of clinical conditions ranging from the treatment of life-threatening graft-versus-host disease to cartilage repair. Development of cell and tissue engineered products derived from MSCs will be enabled by scalable production processes with standards of safety and efficacy similar to those established for the pharmaceutical industry. Many of the bioreactor design principles established for production of biopharmaceuticals can be applied to production of MSC products; however, specific control of the microenvironment is required for MSC expansion and differentiation. We review how porous scaffolds and bioreactor technologies are applied to the study of the MSC microenvironment. Current methods for MSC production are based on growth in tissue culture flasks, which is labour-intensive and expensive. We suggest that stirred, perfusion or microfluidic bioreactor technologies can more efficiently address the clinical need for large-scale MSC production. Soft lithography and microfluidic design offer extreme geometric precision to study MSC function as well as defining the microenvironment for tissue engineering at the micron scale. (c) 2008 Society of Chemical Industry.