ABSTRACT
Membrane systems are becoming an important and strategic tool in the fi eld of biomedical engineering and regenerative medicine. This emerging fi eld combines more established disciplines like engineering, chemistry, biochemistry, biology and medicine with the same fi nal goal: the realization of tuneable microenvironments to restore, maintain or improve tissue functions (Langer and Vacanti 1993). The role of biomaterials in the fi eld of tissue engineering has evolved from the early ideas of an inert scaffolding device (Hench 1980) to one in which biomatrices are actively contributing to the regeneration of tissue (Hench and Polak 2002, Stevens and George 2005). The biomaterial scaffold serves to house the cells supporting their growth and adhesion and to direct their reorganization in a three-dimensional architecture exposing them to an adequate perfusion of nutrients, oxygen, metabolic products and growth factors to guide their differentiation
1Institute on Membrane Technology, National Research Council of Italy, ITM-CNR, c/o University of Calabria, via P. Bucci cubo 17/C, Rende (CS) Italy. aEmail: s.salerno@itm.cnr.it 2Department of Chemical Engineering and Materials, University of Calabria, via P. Bucci, Rende (CS) Italy. 3WCU Energy Engineering Department, Hanyang University, Seoul 133-791 S. Korea. *Corresponding author
and functions (Moreno-Borchart 2004). Organ level tissue engineering requires a microenvironment that not only provides substrates for cell proliferation but also affords signalling cues directing morphogenesis and cell differentiation into tissue-specifi c structures (Rustad et al. 2010). In the last few years different polymeric membranes with suitable properties of biocompatibility, biostability, selectivity in transport phenomena and ability in promoting favourable cell interactions offered interesting opportunities for the design of artifi cial organs (Drioli and De Bartolo 2006) and innovative medical therapies and research strategies for the next 20 yr will focus on the implantation of bioartifi cial tissue and the induction of the regeneration (De Bartolo et al. 2012). The new developed membranes have been widely used for in vitro cell culture in the absence of the endogenous tissue. Many tissue properties can be mimicked with membranes such as the structured environment with tissue specifi c mechanical strength and a porous niche for cell adhesion. Membrane systems supporting and stimulating cell differentiation and proliferation have been involved in the biofabrication of active substitutes in static and dynamic conditions. The great impact of membrane systems in tissue engineering is represented not only by the ambition of reproducing complex integrated membrane artifi cial organs to use as implantable or extracorporeal devices for tissue loss or organ failure, but is further addressed for the designing of in vitro physiological models. A homogeneous and stable in vivo-like microenvironment can be employed as a valid tool to study diseases, to investigate the basic biology of tissue development as well as to develop therapeutic strategies for drugscreening applications. In particular hepatocyte bioreactors with different confi guration and a well defi ned fl uid dynamic microenvironment have been designed and tested to evaluate both therapeutic and toxicological effects of various drugs and chemicals on hepatic metabolism.
