title: Multilayer nanofilms as substrates for hepatocellular applications.
abstract: Multilayer nanofilms, formed by the layer-by-layer (LbL) adsorption of positively and negatively charged polyelectrolytes, are promising substrates for tissue engineering. We investigate here the attachment and function of hepatic cells on multilayer films in terms of film composition, terminal layer, rigidity, charge, and presence of biofunctional species. Human hepatocellular carcinoma (HepG2) cells, adult rat hepatocytes (ARH), and human fetal hepatoblasts (HFHb) are studied on films composed of the polysaccharides chitosan (CHI) and alginate (ALG), the polypeptides poly(l-lysine) (PLL) and poly(l-glutamic acid) (PGA), and the synthetic polymers poly(allylamine hydrochloride) (PAH) and poly(styrene sulfonate) (PSS). The influence of chemical cross-linking following LbL assembly is also investigated. We find HepG2 to reach confluence after 7 days of culture on only 2 of 18 candidate multilayer systems: (PAH-PSS)(n) (i.e. nPAH-PSS bilayers) and cross-linked (PLL-ALG)(n)-PLL. Cross-linked PLL-ALG and PLL-PGA films support attachment and function of ARH, independently of the terminal layer, provided collagen is adsorbed to the top of the film. (PAH-PSS)(n), cross-linked (PLL-ALG)(n), and cross-linked (PLL-PGA)(n)-PLL films all support attachment, layer confluence, and function of HFHb, with the latter film promoting the greatest level of function at 8 days. Overall, film composition, terminal layer, and rigidity are key variables in promoting attachment and function of hepatic cells, while film charge and biofunctionality are somewhat less important. These studies reveal optimal candidate multilayer biomaterials for human liver tissue engineering applications.
authors.affiliation: Department of Chemical Engineering, Yale University, New Haven, CT 06520-8286, USA.
authors.forename: Corinne R
authors.initials: CR
authors.lastname: Wittmer
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Phelps
authors.forename: Christin M
authors.initials: CM
authors.lastname: Lepus
authors.forename: William M
authors.initials: WM
authors.lastname: Saltzman
authors.forename: Martha J
authors.initials: MJ
authors.lastname: Harding
authors.forename: Paul R
authors.initials: PR
authors.lastname: Van Tassel
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry; D002448:Cell Adhesion; D018929:Cell Culture Techniques / Q000379:methods; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D022781:Hepatocytes / Q000166:cytology* / Q000502:physiology*; D006801:Humans; D008422:Materials Testing; D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D051381:Rats; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods*
chemical_list: D001672:Biocompatible Materials; D008567:Membranes, Artificial