title: Stable immobilization of rat hepatocyte spheroids on galactosylated nanofiber scaffold.
abstract: Primary rat hepatocytes self-assemble into multi-cellular spheroids and maintain differentiated functions when cultured on a two-dimensional (2-D) substrate conjugated with galactose ligand. The aim of this study is to investigate how a functional nanofiber scaffold with surface-galactose ligand influences the attachment, spheroid formation and functional maintenance of rat hepatocytes in culture, as compared with the functional 2-D substrate. Highly porous nanofiber scaffolds comprising of fibers with an average diameter of 760 nm were prepared by electrospinning of poly(epsilon-caprolactone-co-ethyl ethylene phosphate) (PCLEEP), a novel biodegradable copolymer. Galactose ligand with a density of 66 nmol/cm(2) was achieved on the nanofiber scaffold via covalent conjugation to a poly(acrylic acid) spacer UV-grafted onto the fiber surface. Hepatocytes cultured on the galactosylated PCLEEP nanofiber scaffold exhibited similar functional profiles in terms of cell attachment, ammonia metabolism, albumin secretion and cytochrome P450 enzymatic activity as those on the functional 2-D substrate, although their morphologies are different. Hepatocytes cultured on galactosylated PCLEEP film formed 50-300 microm spheroids that easily detached from surface upon agitation, whereas hepatocytes cultured on galactosylated nanofiber scaffold formed smaller aggregates of 20-100 microm that engulfed the functional nanofibers, resulting in an integrated spheroid-nanofiber construct.
authors.affiliation: Divison of Biomedical Sciences, Johns Hopkins in Singapore, Singapore 138669.
authors.forename: Kian-Ngiap
authors.initials: KN
authors.lastname: Chua
authors.forename: Wei-Seng
authors.initials: WS
authors.lastname: Lim
authors.forename: Pengchi
authors.initials: P
authors.lastname: Zhang
authors.forename: Hongfang
authors.initials: H
authors.lastname: Lu
authors.forename: Jie
authors.initials: J
authors.lastname: Wen
authors.forename: Seeram
authors.initials: S
authors.lastname: Ramakrishna
authors.forename: Kam W
authors.initials: KW
authors.lastname: Leong
authors.forename: Hai-Quan
authors.initials: HQ
authors.lastname: Mao
mesh_terms: D000327:Adsorption; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects / Q000502:physiology; D018929:Cell Culture Techniques / Q000379:methods; D048429:Cell Size / Q000187:drug effects; D002470:Cell Survival / Q000502:physiology; D002478:Cells, Cultured; D018914:Cells, Immobilized / Q000187:drug effects / Q000502:physiology; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology; D004146:Dioxanes / Q000737:chemistry*; D005690:Galactose / Q000737:chemistry / Q000494:pharmacology*; D022781:Hepatocytes / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D019164:Liver, Artificial; D008297:Male; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D011091:Polyesters / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D018874:Spheroids, Cellular / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D020099:Coated Materials, Biocompatible; D004146:Dioxanes; D011091:Polyesters; C095495:glycolide E-caprolactone copolymer; D005690:Galactose