Polymeric membranes used in bioreactors for bioartificial livers are generally chosen for their transport and separation properties to provide liver cells with adequate nutrients supply and avoid rejection. Possible effects of membrane surface properties on cell metabolism are generally given little consideration. The reported effects of membrane surface wettability on adherent liver cells are qualitative and inconsistent, possibly due to the variation of other surface properties and the culture in Petri dishes, often at confluence, under uncontrolled time- and space-varying metabolite concentrations. In this investigation, rat liver cells were cultured in sub-confluent adhesion on model membranes hydrophilized by physical treatment featuring varying surface wettability in a continuous-flow recycle bioreactor. Bioreactor optimization permitted to culture cells at uniform and measurable pericellular concentrations of metabolic substrates, and to challenge them with controlled increasing ammonia concentrations. Membrane surface wettability was characterized in terms of water sorption, dynamic contact angle, and oxygen content by XPS. The kinetics of oxygen consumption, ammonia elimination and urea synthesis of cells adherent on membranes with increasing wettability was characterized at increasing ammonia concentrations. Cells exhibited increasingly better metabolic functions on membranes with increasing surface wettability. Metabolic reaction rate differences were increasingly more evident at increasing ammonia concentrations. Membrane surface wettability appeared to mainly affect cell capacity to respond to the ammonia challenge. © 2014 Elsevier B.V.

Surface wettability of model microporous membranes enhances rat liver cell functions in sub-confluent adherent culture in a continuous-flow recycle bioreactor depending on the ammonia concentration challenge

Catapano, Gerardo
2014-01-01

Abstract

Polymeric membranes used in bioreactors for bioartificial livers are generally chosen for their transport and separation properties to provide liver cells with adequate nutrients supply and avoid rejection. Possible effects of membrane surface properties on cell metabolism are generally given little consideration. The reported effects of membrane surface wettability on adherent liver cells are qualitative and inconsistent, possibly due to the variation of other surface properties and the culture in Petri dishes, often at confluence, under uncontrolled time- and space-varying metabolite concentrations. In this investigation, rat liver cells were cultured in sub-confluent adhesion on model membranes hydrophilized by physical treatment featuring varying surface wettability in a continuous-flow recycle bioreactor. Bioreactor optimization permitted to culture cells at uniform and measurable pericellular concentrations of metabolic substrates, and to challenge them with controlled increasing ammonia concentrations. Membrane surface wettability was characterized in terms of water sorption, dynamic contact angle, and oxygen content by XPS. The kinetics of oxygen consumption, ammonia elimination and urea synthesis of cells adherent on membranes with increasing wettability was characterized at increasing ammonia concentrations. Cells exhibited increasingly better metabolic functions on membranes with increasing surface wettability. Metabolic reaction rate differences were increasingly more evident at increasing ammonia concentrations. Membrane surface wettability appeared to mainly affect cell capacity to respond to the ammonia challenge. © 2014 Elsevier B.V.
2014
Ammonia; Consumption kinetics; Liver cells; Membrane wettability; Oxygen; Biochemistry; Materials Science (all); Physical and Theoretical Chemistry; Filtration and Separation
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11770/275081
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 2
  • ???jsp.display-item.citation.isi??? 0
social impact