Abstract

Engineering of Complex 3-D-Tissues

Heike Walles, Chair/Head, University Hospital of Wuerzburg

Vascularization is a major challenge in creating tissues ex vivo. Complex tissue engineered constructs exceeding a thickness of 100-200 µm need a vascular system in order to supply the cells with oxygen and nutrients and moreover remove waste products. We developed 3D vascularized tissues based on decellularized porcine small bowl segments and preserved tubular structures of the capillary network within the collagen matrix which is functional associated with one small vein and artery (biological vascularized scaffold - BioVaSc). This vascularized matrix enables the generation of a functional artificial vascular network and vascularized tissues as trachea, bone, skin, fatty tissue, intestine, liver and tumour. These vascularized tissues are applied as tissue models as a preliminary stage to animal experiments for investigations of functional parameters like the penetration, the distribution and metabolization of substances in different tissue layers. Further, with the help of suitable markers, issues concerning the proliferation, differentiation, cell death (necrosis, apoptosis), but also, the initiation and graduation of tumors of the applied cell types can be examined. Non-invasive monitoring of such engineered tissues during their in vitro maturation or post implantation in vivo is relevant for graft evaluation. However, traditional methods to analyse cell and matrix components in tissue engineered constructs such as histology, immuno-histochemistry or biochemistry requires invasive tissue processing, resulting in scarification of these constructs. At the end of the presentation an overview of non-destructive methods to characterize the complex implants will be given. Our Team is focusing on the impedance and Raman spectroscopy for these applications.