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ABSTRACT: Tissue engineering of vascular grafts still presents several shortcomings. Aiming to vascular regeneration, we developed a biomimetic multilayered scaffold with a middle pivotal collagen lamina between two functionalized layers of poly-L-lactide by means of electrospinning technique, with oriented drug-delivery capacity for the differentiation of human mesenchymal stem cells seeded therein. Applying appropriate cytokines, the inner layer is able to act as a drug delivery system in order to generate a pro-angiogenic and anti-thrombotic environment and the outer one is used to induce the media and adventitia generation. Our findings are consistent with an adequate cell engrafting and a double type of differentiation in each side of the scaffold, in particular cells exhibited morphostructural changes resulting in the achievement of an endothelial-like phenotype in cells populating the inner side of the scaffold and SMA positivity with cell elongation resembling muscular phenotype in the cells of the outer layer. The proposed “smart” vascular bio-prosthesis will recapitulate the structure and microenvironment of native cardiovascular tissues. It could surmount many hurdles to clinical use and would be relevant for therapeutic applications in a variety of medical fields.
Engineering in Medicine and Biology Society (EMBC), 2010 Annual International Conference of the IEEE; 10/2010
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ABSTRACT: Targeting wound repair, we developed an electrospun poly-L-lactide fibrous scaffold functionalized with G-CSF, a growth factor which is widely recognized as important in wound healing homeostasis. The scaffold was characterized in terms of morphology, mechanical properties and in vitro capacity to induce organization of co-cultures of murine fibroblasts and keratinocytes into a dermo-epidermal multilayered structure. Our findings are consistent with the promotion of a nonhostile environment, in which seeded cells could arrange themselves in an appropriate topographic distribution of elements at different levels of maturation up to a cornified epithelium on the top layer, resembling native skin.
Engineering in Medicine and Biology Society (EMBC), 2010 Annual International Conference of the IEEE; 10/2010
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ABSTRACT: Tissue engineering of blood vessels is a promising strategy in regenerative medicine with a broad spectrum of potential applications. However, many hurdles for tissue-engineered vascular grafts, such as poor mechanical properties, thrombogenicity and cell over-growth inside the construct, need to be overcome prior to the clinical application. To surmount these shortcomings, we developed a poly-L-lactide (PLLA)/poly-epsilon-caprolactone (PCL) scaffold releasing heparin by a combination of electrospinning and fused deposition modeling technique. PLLA/heparin scaffolds were produced by electrospinning in tubular shape and then fused deposition modeling was used to armor the tube with a single coil of PCL on the outer layer to improve mechanical properties. Scaffolds were then seeded with human mesenchymal stem cells (hMSCs) and assayed in terms of morphology, mechanical tensile strength, cell viability and differentiation. This particular scaffold design allowed the generation of both a drug delivery system amenable to surmount thrombogenic issues and a microenvironment able to induce endothelial differentiation. At the same time, the PCL external coiling improved mechanical resistance of the microfibrous scaffold. By the combination of two notable techniques in biofabrication--electrospinning and FDM--and exploiting the biological effects of heparin, we developed an ad hoc differentiating device for hMSCs seeding, able to induce differentiation into vascular endothelium.
Biofabrication 03/2010; 2(1):014102. · 3.48 Impact Factor
