Mass transfer properties, synthetic

Naruse et al. proposed another bioreactor design [22,23], in which porcine hepatocyte spheroids are immobilized on non-woven polyester fabric. This device allows more direct contact between hepatocytes and perfused medium and improves, therefore, the mass transfer capacity. The non-woven fabric module expressed better metabohc and synthetic functions at 24 hours than a hollow fiber module containing spheroids in suspension culture. Longer term results are not yet available and the immunoexclusion properties of this fabric have not been addressed. 

FIGURE 41.2 Basic principle of artificial cells Artificial cells are prepared to have some of the properties of biological cells. Like biological cells, artificial cells contain biologically active materials (I). The enclosed material (I) can be retained and separated from undesirable external materials, such as antibodies, leukocytes, and destructive substances. The large surface area and the ultra-thin membrane allow selected substrates (X) and products (Y) to permeate rapidly. Mass transfer across 100 mL of artificial cells can be 100 times higher than that for a standard hemodialysis machine. The synthetic membranes are usually made of ultrathin synthetic polymer membranes for this type of artificial cell. (From Chang, T.M.S., Artif. Cells Blood Substit. ImmobU. Biotechnol., 22(1), vii, 1994.)... 

Furthermore, disadvantages caused by heterogeneous catalysis, such as mass-transfer limitations and alteration of catalytic properties, are largely avoided [446]. A variety of synthetic membranes are available in various shapes such as foils or hollow fibers. 

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