Direct oxygen supply with polydimethylsiloxane (PDMS) membranes induces a spontaneous organization of thick heterogeneous liver tissues from rat fetal liver cells in vitro.
Oxygen is a vital nutrient for growth and maturation of in vitro cells (e.g., adult hepatocytes). We previously demonstrated that direct oxygenation through a polydimethylsiloxane (PDMS) membrane increases the oxygen supply to cell cultures and improves hepatocyte functions. In this  study, we removed limits on oxygen supply to fetal rat liver cells through the use of direct oxygenation through a PDMS membrane to investigate in vitro growth and maturation. We chose fetal liver cells because they are considered a feasible source of liver progenitor cells for regenerative  medicine therapy due to their highly efficient maturation and proliferation. Cells from 17-day-old pregnant rats were cultured under 5% and 21% oxygen atmospheres. Some cells were first cultured under 5% oxygen, and then switched to a 21% oxygen atmosphere. When oxygen supply was enhanced  by a PDMS membrane, the rat fetal liver cells organized into a complex tissue composed of an epithelium of hepatocytes above a mesenchyme-like tissue. The thickness of this supportive tissue was directly correlated to oxygen concentration and was thicker under 5% oxygen. When cultures were  switched from 5% to 21% oxygen, lumen-containing structures were formed in the thick mesenchymal-like tissue and the albumin secretion rate increased. In addition, cells adapted their glycolytic activity to the oxygen concentrations. This system promoted the formation of a functional and organized  thick tissue suitable for use in regenerative medicine.
Laboratory for Integrated Micro-Mechatronic Systems, Institute of Industrial Science, University of Tokyo, Meguro-ku, Tokyo, Japan. mhamon@iis.u-tokyo.ac.jp
Morgan
M
Hamon
Sanshiro
S
Hanada
Teruo
T
Fujii
Yasuyuki
Y
Sakai
D000818:Animals; D018929:Cell Culture Techniques; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D005260:Female; D005333:Fetus / Q000166:cytology*; D005947:Glucose / Q000378:metabolism; D019344:Lactic Acid / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000378:metabolism / Q000473:pathology*; D008567:Membranes, Artificial; D008954:Models, Biological; D010100:Oxygen / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000502:physiology; D010539:Permeability; D011247:Pregnancy; D051381:Rats; D044968:Regenerative Medicine
D004129:Dimethylpolysiloxanes; D008567:Membranes, Artificial; D019344:Lactic Acid; C013830:baysilon; D005947:Glucose; D010100:Oxygen