Stereotypic culture systems for liver and bone marrow: Evidence for the development of functional tissue in vitro and following implantation in vivo

Abstract

Stromal cell-associated liver cell and bone marrow (BM) culture on three-dimensional nylon screen or polyglycolic acid (PGA) felt templates conveys certain functional advantages to the parenchyma of these tissues. Hepatic parenchymal cells (PC) manifest long-term ( approximately 2 month) expression of liver-specific activities including cytochrome P450 enzyme activity and the synthesis of albumin, fibrinogen, transferrin, and other proteins. PC also undergo proliferation in association with stromal cells that were pre-established on these templates. PC mitoses are directly proportional to available space within the template for their expansion indication that geometric or sterotypic parameters influence the growth of these cells in vitro. BM cultured on a similar template exhibits long-term multilineage hematopoietic expression and limited expansion of progenitor cell numbers. Progenitor cell concentration within the cultures can be substantially enhanced if these cells are liberated from co-culture and reseeded onto a template containing fresh stromal cells. BM and liver cel cultures established on felt composed of bioresorbable PGA filaments was grafted into various sites in rats. Liver co-cultures generated sinusoids and other liver-like structures in situ; active hematopoietic blasts were observed at sites of BM co-culture grafts. Biodegradable polymer constructs may prove useful for certain clinical applications as vehicles for the delivery of tissues that were engineered in culture.

Effect of cell–cell interactions in preservation of cellular phenotype: cocultivation of hepatocytes and nonparenchymal cells

“…One study showed a 12‐ to 15‐fold increase in mRNA levels for CYP2B1 after 7 days of induction of cocultures by phenobarbital as compared to hepatocytes cultured alone (81). Although each isoenzyme shows a different induction pattern, some have been reported to be inducible for up to 2 months (82). On the other hand, cocultivation does not preserve all isoenzyme activities; some, such as 2C11, 2C6, and 2E1, were reported to decline continuously (45, 46, 79, 80).…”

Hydrogel-coated textile scaffolds as candidate in liver tissue engineering: II. Evaluation of spheroid formation and viability of hepatocytes

“…Microstructure and conformational features of scaffolds have been demonstrated to govern level of differentiation and hepatocyte aggregate behavior in culture [7,8]. We have earlier demonstrated the suitability of textile scaffolds in inducing hepatocyte aggregate formation [9,10].…”

Induction of three-dimensional assembly of human liver cells by simulated microgravity

“…with a synthetic matrix of biodegradable polymeric scaffolds composed of polyglycolic acid (PGA) (4,14). These cells produced albumin (4) and expressed cytochrome P450 enzyme activity that was measured by the ability of cells to transform the nonfluorescent compound ethoxy-fluoreseein ~To whom correspondence should be addressed: Boris Yoffe, M.D., VAMC (151B), 2002 Holcombe Boulevard, Houston, Texas 77030. ethyl ester to fluorescein (14). Hepatocyte cultures have also been maintained with an artificial capillary system and a hollow fiber binreactor with cells entrapped in collagen (9,21).…”