A Full Skin Defect Model to Evaluate Vascularization of Biomaterials <em>In Vivo</em>

Abstract

Insufficient vascularization is considered to be one of the main factors limiting the clinical success of tissue-engineered constructs. In order to evaluate new strategies that aim at improving vascularization, reliable methods are required to make the in-growth of new blood vessels into bioartificial scaffolds visible and quantify the results. Over the past couple of years, our group has introduced a full skin defect model that enables the direct visualization of blood vessels by transillumination and provides the possibility of quantification through digital segmentation. In this model, one surgically creates full skin defects in the back of mice and replaces them with the material tested. Molecules or cells of interest can also be incorporated in such materials to study their potential effect. After an observation time of one's own choice, materials are explanted for evaluation. Bilateral wounds provide the possibility of making internal comparisons that minimize artifacts among individuals as well as of decreasing the number of animals needed for the study. In comparison to other approaches, our method offers a simple, reliable and cost effective analysis. We have implemented this model as a routine tool to perform high-resolution screening when testing vascularization of different biomaterials and bio-activation approaches. Video LinkThe video component of this article can be found at

Hypoxic pre-conditioning increases the infiltration of endothelial cells into scaffolds for dermal regeneration pre-seeded with mesenchymal stem cells

“…All animal procedures were performed strictly adhering to protocols approved by the Institutional Animal Care and Use Committee at UC Davis. Two excisional wounds were generated bilaterally on the flanks of immune deficient NOD/SCID IL2Rγ –/– (NSG) mice, as previously described (Egaña et al, 2009 ; Schenck et al, 2014 ). Briefly, animals were placed under anesthesia (1.5–3% isoflurane), fur was shaved and an area of skin was removed on both the left and/or right flank of the animal using a 10 mm biopsy punch.…”

Towards autotrophic tissue engineering: Photosynthetic gene therapy for regeneration

“…In order to quantify the rate of vascularization over the wound, tissue transillumination and digital segmentation was performed as described before [21]. Briefly, the skin from the back of the animals was removed and stretched out on a petri dish over a transilluminator device.…”

Photosynthetic biomaterials: A pathway towards autotrophic tissue engineering

“…Experiments were performed on female nu/nu mice of 6-8 weeks age and body weight of 6 20-25 g (Charles River, Sulzfeld, Germany). Under inhalative anesthesia (Isoflurane, Baxter Germany, Unterschleissheim, Germany), a bilateral 10 mm full skin defect was created as we described before [19]. Control and HULK scaffolds were implanted and covered with a transparent dressing (V.A.C.® Drape, KCI Medical Products, Wimborne Dorset, UK).…”