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Surface biofunctionalisation of many biodegradable polymers is one of the used strategies to improve the biological activity of such materials. In this work, the introduction of collagen type I over the surface of a biodegradable polymer (poly lactic acid) processed in the forms of films and fibers leads to an enhancing of the cellular adhesion of human dermal fibroblast when compared to unmodified polymer and biomolecule-physisorbed polymer surface. The change of topography of the material does not affect the cellular adhesion but results in a higher proliferation of the fibroblast cultured over the fibers. Moreover, the difference of topography governs the cellular morphology, i.e. cells adopt a more stretched conformation where cultured over the films while a more elongated with lower area morphology are obtained for the cells grown over the fibers. This study is relevant for designing and modifying different biodegradable polymers for their use as scaffolds for different applications in the field of Tissue Engineering and Regenerative Medicine.

This is a copy of an article published in Tissue Engineering: Part C and it is available online at http://online.liebertpub.com, Successful preliminary studies have encouraged a more translational phase for stem cell research. Nevertheless, advances in the culture of human bone marrow-derived mesenchymal stromal/stem cells (hBM-MSC) and osteoconductive qualities of combined biomaterials can be undermined if necessary cell transportation procedures prove unviable. We aimed at evaluating the effect of transportation conditions on cell function, including the ability to form bone in vivo, using procedures suited to clinical application. hBM-MSC expanded in current Good Manufacturing Practice (cGMP) facilities (cGMP-hBM-MSC) to numbers suitable for therapy were transported overnight within syringes and subsequently tested for viability. Scaled-down experiments mimicking shipment for 18 h at 4 C tested the influence of three different clinical-grade transportation buffers (0.9% saline alone or with 4% human serum albumin [HSA] from two independent sources) compared with cell maintenance medium. Cell viability after shipment was > 80% in all cases, enabling evaluation of (1) adhesion to plastic flasks and hydroxyapatite tricalcium phosphate osteoconductive biomaterial (HA/b-TCP 3D scaffold); (2) proliferation rate; (3) ex vivo osteogenic differentiation in contexts of 2D monolayers on plastic and 3D HA/b- TCP scaffolds; and (4) in vivo ectopic bone formation after subcutaneous implantation of cells with HA/b-TCP scaffold into NOD/SCID mice. Von Kossa staining was used to assess ex vivo osteogenic differentiation in 3D cultures, providing a quantifiable test of 3D biomineralization ex vivo as a rapid, cost-effective potency assay. Near-equivalent capacities for cell survival, proliferation, and osteogenic differentiation were found for all transportation buffers. Moreover, cGMP-hBM-MSC transported from a production facility under clinical-grade conditions of 4% HSA in 0.9% saline to a destination 18 h away showed prompt adhesion to HA/b-TCP 3D scaffold and subsequent in vivo bone formation. A successfully validated transportation protocol extends the applicability of fresh stem cells involving multicentric trials for regenerative medicine, This work was supported in part by the European Commission Seventh Framework Program (FP7/2007–2013) (grant no. 241879), through the REBORNE project, the Italian Ministry of Health ‘‘Bando Cellule Staminali 2008’’ (M.D., P.P.), Regione Emilia Romagna (P.P., M.D.), and the Associazione ASEOP (P.P.).