title: Hepatocyte viability and protein expression within hydrogel microstructures.
abstract: Poly(ethylene) glycol (PEG) hydrogels have been successfully used to entrap mammalian cells for potential high throughput drug screening and biosensing applications. To determine the influence of PEG composition on the production of cellular protein, mammalian hepatocytes were maintained in PEG hydrogels for 7 days. Total cell viability, total protein production, and the production of two specific proteins, albumin and fibronectin, were monitored. Studies revealed that while PEG composition has no effect on cell viability, increasing amounts of PEG in the hydrogel decrease the amount of protein production by the cells after 7 days from 1.0 x 10(5) +/- 1.7 x 10(4) to 5.2 x 10(3) +/- 1.3 x 10(3) g accumulated protein/mL/million cells. Additionally, cells entrapped in PEG hydrogels produce greater amounts of protein than traditional monolayer culture (1.5 x 10(3) +/- 1.9 x 10(2) g accumulated protein/mL/million cells after 7 days). The addition of the synthetic peptide RGD to 10% PEG hydrogels altered the production of the proteins albumin and fibronectin. Hydrogels with the RGD sequence produced 287 +/- 27 ng/mL/million cells albumin after 7 days, an order of magnitude greater than monolayer cultures, whereas cells in hydrogels without the RGD sequence produced undetectable levels of albumin. Conversely, cells entrapped in 10% PEG hydrogels without the RGD sequence produced 1014 +/- 328 ng/mL/million cells fibronectin after 7 days, whereas 10% PEG hydrogels with the RGD sequence produced 200 +/- 58 ng/mL/million cells fibronectin after 7 days.
authors.affiliation: Department of Chemical Engineering, The Huck Institute for the Life Sciences, The Pennsylvania State University, University Park, Pennsylvania 16802-4420, USA.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Itle
authors.forename: Won-Gun
authors.initials: WG
authors.lastname: Koh
authors.forename: Michael V
authors.initials: MV
authors.lastname: Pishko
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D001681:Biological Assay / Q000379:methods; D018929:Cell Culture Techniques / Q000379:methods*; D002460:Cell Line; D002470:Cell Survival / Q000502:physiology; D005353:Fibronectins / Q000378:metabolism*; D020869:Gene Expression Profiling; D022781:Hepatocytes / Q000166:cytology* / Q000502:physiology*; D020100:Hydrogels / Q000737:chemistry*; D008422:Materials Testing; D051379:Mice; D011092:Polyethylene Glycols / Q000737:chemistry*; D012709:Serum Albumin / Q000378:metabolism*
chemical_list: D001672:Biocompatible Materials; D005353:Fibronectins; D020100:Hydrogels; D012709:Serum Albumin; D011092:Polyethylene Glycols