Human Mesenchymal Stem Cells Seeded on Extracellular Matrix-Scaffold: Viability and Osteogenic Potential LETIZIA PENOLAZZI, 1 STEFANIA MAZZITELLI, 1 RENATA VECCHIATINI, 1 ELENA TORREGGIANI, 1 ELISABETTA LAMBERTINI, 1 SCOTT JOHNSON, 2 STEPHEN F. BADYLAK, 2 ROBERTA PIVA, 1 * AND CLAUDIO NASTRUZZI 3 1 Department of Biochemistry and Molecular Biology, University of Ferrara, Ferrara, Italy 2 McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 3 Department of Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy The development and the optimization of novel culture systems of mesenchymal osteoprogenitors are some of the most important challenges in the field of bone tissue engineering (TE). A new combination between cells and extracellular matrix (ECM)-scaffold, containing ECM has here been analyzed. As source for osteoprogenitors, mesenchymal stem cells obtained from human umbilical cord Wharton’s Jelly (hWJMSCs), were used. As ECM-scaffold, a powder form of isolated and purified porcine urinary bladder matrix (pUBM), was employed. The goals of the current work were: (1) the characterization of the in vitro hWJMSCs behavior, in terms of viability, proliferation, and adhesion to ECM-scaffold; (2) the effectiveness of ECM-scaffold to induce/modulate the osteoblastic differentiation; and (3) the proposal for a possible application of cells/ECM-scaffold construct to the field of cell/TE. In this respect, the properties of the pUBM-scaffold in promoting and guiding the in vitro adhesion, proliferation, and three-dimensional colonization of hWJMSCs, without altering viability and morphological characteristics of the cells, are here described. Finally, we have also demonstrated that pUBM-scaffolds positively affect the expression of typical osteoblastic markers in hWJMSCs. J. Cell. Physiol. 227: 857–866, 2012. ß 2011 Wiley Periodicals, Inc. Recently, native allogenic or xenogenic extracellular matrix (ECM) has been proposed for clinical use in tissue engineering (TE) approaches, with the aim to possibly ameliorate tissue regeneration (Wollenweber et al., 2006; Badylak, 2007; Chan and Mooney, 2008). Unfortunately, clinical application of TE technologies has been restricted to a relatively limited number of biomaterials. Among them, structural proteins such as collagen, gelatine, and fibronectin have been used as vehicles for cell seeding and in vivo implantation, since they can approximate the structure and function of ECM (Vinatier et al., 2009; Ode et al., 2010). Nevertheless, it is noteworthy that tissue morphogenesis is heavily influenced by the interaction of cells with the complex architecture and chemical composition of natural ECM (Beattie et al., 2009; Guilak et al., 2009; Iop et al., 2009; Pennesi et al., 2010). Simple polymers provide mechanical support to the seeded/entrapped cells, but do not adequately mimic the multiple interactions between adult stem, progenitor cells, and the ECM, during neo-tissue development. In this respect, exogenous ECM-based biomaterials can provide a native framework for cell adhesion, at the site of a tissue deficit, allowing local cells to migrate into the matrix, adhere, and undergo differentiation. These effects are mediated both by natural ECM signaling and regulatory functions and soluble signals provided by growth factors and hormones. Furthermore, ECM is characterized by a dynamic 3D-architecture, continuously modified by complex interactions with homing cells (Docheva et al., 2007; Badylak et al., 2009). The great complexity of ECM and its unique features, has since now, strongly hurdled the development of laboratory methods for the complete assembly of a true, native ECM from isolated and purified components. Therefore, decellularized tissues or organs have been proposed as sources of biological ECM for TE (Badylak et al., 2009; Nam et al., 2010; Soto-Gutierrez et al., 2010; Stabile et al., 2010; Yang et al., 2010). The relatively high degree of evolutionary conservation of many ECM components has permitted the use of xenogeneic materials. Various acellular matrices have been utilized successfully for TE in animal models and a limited number of xenogeneic products have received regulatory approval for clinical use, including decellularized heart valves, small intestinal submucosa, and urinary bladder matrix (Hodde, 2002; Gabouev et al., 2003; Aitken and Ba ¨gli, 2009; Okada et al., 2010; Zhou et al., 2010). Porcine ECM, derived from urinary bladder used as biomaterials [named throughout the text as porcine urinary bladder matrix (pUBM)-scaffold], can provide the necessary structural support and dynamic exchange signals to local cells leading to tissue infill. The major constituents found in UBM are collagen (types I, III, and IV–VII), glycoproteins (such as fibronectin and laminin), glycosaminoglycans (GAGs) and various growth factors, including transforming growth factor-b, basic fibroblast growth factor and vascular endothelial growth factor (Badylak, 2007; Badylak et al., 2009; Brown et al., 2010; Mazzitelli et al., 2011). *Correspondence to: Roberta Piva, Department of Biochemistry and Molecular Biology, University of Ferrara, Via Fossato di Mortara, 74, 44121 Ferrara, Italy. E-mail: piv@unife.it Received 4 April 2011; Accepted 3 August 2011 Published online in Wiley Online Library (wileyonlinelibrary.com), 9 August 2011. DOI: 10.1002/jcp.22983 ORIGINAL RESEARCH ARTICLE 857 Journal of Journal of Cellular Physiology Cellular Physiology ß 2011 WILEY PERIODICALS, INC.