New pulsatile bioreactor for fabrication of tissue-engineered patches

To date, one approach to tissue engineering has been to develop in vitro co nditions to ultimately fabricate functional cardiovascular structures prior to final implantation, In our current experiment, we developed a new pulsa tile flow system that provides biochemical and biomechanical signals to reg ulate autologous patch-tissue development in vitro. The newly developed pat ch bioreactor is made of Plexiglas and is completely transparent (Mediport Kardiotechnik, Berlin), The bioreactor is connected to an air-driven respir ator pump, and the cell culture medium continuously circulates through a cl osed-loop system. We thus developed a closed-loop, perfused bioreactor for long-term patch-tissue conditioning, which combines continuous, pulsatile p erfusion and mechanical stimulation by periodically stretching the tissue-e ngineered patch constructs. By adjusting the stroke volume, the stroke rate , and the inspiration/expiration time of the ventilator, it allows various pulsatile flows and different levels of pressure. The whole system is a hig hly isolated cell culture setting, which provides a high level of sterility , gas supply, and fits into a standard humidified incubator. The bioreactor can be sterilized by ethylene oxide and assembled with a standard screwdri ver, Our newly developed bioreactor provides optimal biomechanical and biod ynamical stimuli for controlled tissue development and in vitro conditionin g of an autologous tissue-engineered patch. (C) 2001 John Wiley & Sons, Inc .