2006 - UZ Leuven

skin construct displays authentic full thickness skin with its epidermaland dermal extracellular matrix elements, the more accurate thisconstruct will integrate into the wound environment and will elicit therequired cell signaling pathways that will lead to permanent healingand regeneration. However, unlike the extracellular matrix thatrepresents a millenary natural evolution, artificial biomaterials do nothave such a complex structure and chemical composition. Inconsequence, the pay off to large-scale producibility andstandardization of these ‘man-made devices’ is the very low bioinformationcontent and the scarce quantity of signals they transmit tocells. The development of materials that can specifically andmolecularly interact with cells in the defect has become an emergingfield in research. In our research efforts we focus on an integratedconcept of “smart autologous tissue engineering”. Using the plasticityand growing potential of adult progenitor cells and the guidance andstructural capacities of smart biomaterials, we add intelligence byintroducing selected proteins by ex vivo gene transfer technologies.Due to high availability we currently purify lipoaspirate derived adultprogenitor cells as susbtrate and carriers for growth factor release intofull thickness defects.DICKENS S., VERMEULEN P., VRANCKX J.J.: Transfection with atetracyclin inducible VEGF 165 plasmid results in transient regulablehigh expression of VEGF165 in vitro and in vivo. ETRS Bulletin, 2006;13: 59.Background: Pathofysiology of non-healing skin wounds is oftenrelated to an altered GF profile. Ex vivo Gene Transfer of GrowthFactors (GF) shows great promise for gene delivery into tissue in apathological state. Vascular Endothelial Growth Factor (VEGF)promotes neovascularization of granulation tissue in skin wounds andtherefore seems a good candidate for gene therapy. However,controlled release of VEGF is obligatory to prevent hazardous sideeffects.Methods: A hVEGF165 plasmid was ligated into a pcDNA4/TOvector using EcoR1 and EcoR5 restriction sites. This results inhVEGF165 expression under the control of a CMV-promotor and 2Tetracycline operator2 sites (TeTO2). Porcine Keratinocytes (KC)were transfected with pcDNA4/TO.VEGF (1,5 to 3μg) andpcDNA6/TR (repression molecule; 9-18μg) by means of lipofectinin a DNA:lipofectin ratio of 1:4. For in vitro studies, KC culturesupernatans was collected at timepoints 0, 24, 36 and 48 hours afteraddition of 0-5 μg/ml Tetracyclin (TC). For in vivo studies, VEGFtransfected KC are seeded in Full Thickness Wounds (FTW) in a73