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Clinical success in tissue regeneration requires improvements in vascularization capacity of scaffolds. Several efforts have been made in this field including cellular and acellular technologies. In this work we combined the use of stem cells derived from pancreas or submandibular glands expressing green fluorescent protein (GFP(+)) with a commercially available scaffold for dermal regeneration. Cells were isolated, characterized and seeded in a scaffold for dermal regeneration. Scaffolds containing cells were used to induce dermal regeneration in a full skin defect model. After 3 weeks of in vivo regeneration, tissues were harvested and vascularization was analyzed. Results showed that gland-derived stem cells displayed stem cell features and presented multipotential differentiation capacity because they were able to differentiate in cell types representing the 3 different germ layers. After seeding, cells were homogeneously distributed and formed focal adhesions with the scaffold. Metabolic assays showed that cells can be cultured for at least 3 weeks in the scaffold. In vivo, the presence of pancreatic or submandibular stem cells significantly enhanced the vascularization compared to empty scaffolds. Presence of gland-derived stem cells in the regenerating tissue was confirmed by the detection of GFP expression in the wound area. In order to explore the possible mechanisms behind the improvement in vascular regeneration, in vitro experiments were performed, showing that gland-derived stem cells could contribute by angiogenic and vasculogenic mechanisms to this process. Our results suggest that the combined use of stem cells derived from glands and scaffold for dermal regeneration could be a rational alternative to improve vascularization in scaffold-mediated dermal regeneration.

SUMMARY: Recently, a newly recognized familial glomerulopathy with predominant fibronectin deposits has been reported. This is the first report of a family with this condition in Australasia and spans two generations over a 30-year period, with the histologically confirmed glomerulopathy present in the father and five out of eight siblings. The clinical presentations have ranged from asymptomatic proteinuria, pregnancy-associated proteinuria and the nephrotic syndrome to hypertension and proteinuria with progressive renal failure. The time-course from presentation to renal failure was over a 20 years. Histology demonstrated global and diffuse thickening of capillary loops, but no cellular proliferation. Immunofluorescence demonstrated granular positivity for IgM in the capillary loops only. Electron microscopy demonstrated massive electron-dense subendothelial granular deposits with occasional small fibrils and unremarkable epithelial cell foot processes. Immunohistochemical staining was strongly positive for fibronectin and negative for type I or type IV collagen and transforming growth factor b in all biopsies. Genetic studies of familial fibronectin glomerulopathy have recently highlighted two genetic loci. Firstly, a large five-generation pedigree has been described with linkage of fibronectin glomerulopathy to chromosome 1q32. Secondly, fibronectin glomerulopathy has been reported in uteroglobin gene knockout mice. In our studies, DNA sequence analysis of the uteroglobin gene showed that it was normal in all family members, and a DNA polymorphism in the uteroglobin gene did not co-segregate with the disease. In addition, DNA microsatellite markers at the 1q32 locus did not co-segregate with the disease in our family. We presume that the underlying abnormality involves as yet undefined glomerular extracellular matrix regulation and is inherited as an autosomal dominant condition. These data favour genetic heterogeneity for the aetiology of fibronectin glomerulopathy.

Success rates after free tissue transplantation (FTT) have greatly improved over the last 20 years, partly due to improved technical performance of microvascular anastomoses with better optical and instrumental aids. However, flap failure is still a clinical problem and occurs in 5 to 10%, mainly due to blood vessel thrombosis within the first 24 postoperative hours. The clinical results after FTT can be optimized by in-time diagnosis of irreversibly compromised tissue blood flow and immediate operative reexploration. Therefore, there is a special demand for adequate and reliable postoperative monitoring techniques. This article reviews all monitoring techniques which have been performed in the experimental-clinical setting after FTT thus far.

Vascularization is a key process in tissue engineering and regeneration and represents one of the most important issues in the field of regenerative medicine. Thus, several strategies to improve vascularization are currently under clinical evaluation. In the present study, stem cells derived from hu[for full text, please go to the a.m. URL], 49. Jahrestagung der Österreichischen Gesellschaft für Plastische, Ästhetische und Rekonstruktive Chirurgie (ÖGPÄRC), 42. Jahrestagung der Deutschen Gesellschaft der Plastischen, Rekonstruktiven und Ästhetischen Chirurgen (DGPRÄC), 16. Jahrestagung der Vereinigung der Deutschen Ästhetisch-Plastischen Chirurgen (VDÄPC)

The use of scaffolds in skin tissue engineering is accompanied with low regeneration rates and high risk of infection. In this study, we activated an FDA-approved collagen scaffold for dermal regeneration by incorporation of copolymer-protected gene vectors (COPROGs) to induce a temporary release of[for full text, please go to the a.m. URL], 49. Jahrestagung der Österreichischen Gesellschaft für Plastische, Ästhetische und Rekonstruktive Chirurgie (ÖGPÄRC), 42. Jahrestagung der Deutschen Gesellschaft der Plastischen, Rekonstruktiven und Ästhetischen Chirurgen (DGPRÄC), 16. Jahrestagung der Vereinigung der Deutschen Ästhetisch-Plastischen Chirurgen (VDÄPC)

Neovascularization plays a pivotal role in tissue engineering and tissue regeneration. However, reliable technologies to visualize and quantify blood vessel networks in target tissue areas are still pending. In this work, we introduce a new method which allows comparing vascularization levels in normal and tissue-engineered skin. Normal skin was isolated, and vascular dermal regeneration was analyzed based on tissue transillumination and computerized digital segmentation. For tissue-engineered skin, a bilateral full skin defect was created in a nude mouse model and then covered with a commercially available scaffold for dermal regeneration. After 3 weeks, the whole skin (including scaffold for dermal regeneration) was harvested, and vascularization levels were analyzed. The blood vessel network in the skin was better visualized by transillumination than by radio-angiographic studies, the gold standard for angiographies. After visualization, the whole vascular network was digitally segmented showing an excellent overlapping with the original pictures. Quantification over the digitally segmented picture was performed, and an index of vascularization area (VAI) and length (VLI) of the vessel network was obtained in target tissues. VAI/VLI ratio was calculated to obtain the vessel size index. We present a new technique which has several advantages compared to others, as animals do not require intravascular perfusions, total areas of interest can be quantitatively analyzed at once, and the same target tissue can be processed for further experimental analysis.

Augustinus Bader1, Sabine Ebert1, Shibashish Giri1, Mathias Kremer2, Shuhua Liu2, Andreas Nerlich5, Christina I Günter³, Dagmar U Smith4, Hans-Günther Machens2,31Department of Applied Stem Cell Biology and Cell Techniques, Centre for Biotechnology and Biomedicine, University of Leipzig, Leipzieg, 2Department of Plastic and Hand Surgery, University of Lübeck, Lübeck, 3Department of Plastic and Hand Surgery, Technische Universität München, Munich, 4Münchner Studienzentrum, Technische Universität München, Munich, 5Institute of Pathology, Klinikum München-Bogenhausen, Munich, GermanyBackground: Acceleration of skin regeneration is still an unsolved problem in the clinical treatment of patients suffering from deep burns and scalds. Although erythropoietin (EPO) has a protective role in a wide range of organs and cells during ischemia and after trauma, it has been recently discovered that EPO is not tissue-protective in the common β subunit receptor (βCR) knockout mouse. The protective capacity of EPO in tissue is mediated via a heteroreceptor complex comprising both the erythropoietin receptor (EPOR) and βCR. However, proof of coexpression of these heterogenic receptors in regenerating skin after burns is still lacking.Methods: To understand the role of nanosized recombinant human erythropoietin (rhEPO) in wound healing, we investigated the effects of subcutaneous injections of EPO on skin regeneration after deep second-degree scalding injuries. Our aim was to determine if joint expression of EPOR and βCR is a prerequisite for the tissue-protective effect of rhEPO. The efficiency in wound regeneration in a skin scalding injury mouse model was examined. A deep second-degree dermal scald injury was produced on the backs of 20 female Balb/c mice which were subsequently randomized to four experimental groups, two of which received daily subcutaneous injections of rhEPO. At days 7 and 14, the mice were sacrificed and the effects of rhEPO were analyzed with respect to grade of re-epithelialization (wound closure) and stage of epidermal maturation. This was investigated using different histological parameters of epithelial covering, such as depth of the epidermal layer, epidermal stratification, and presence of conical and hair follicle structures.Results: Expression of EPOR, βCR, and growth hormone receptor at the mRNA and protein levels was demonstrated with reverse transcriptase polymerase chain reaction and Western blot analysis. After rhEPO treatment, the rate of re-epithelialization of the scalding injury was increased and the time to final wound closure was reduced. In addition, the quality of regenerated skin was improved. In this investigation, for the first time, we demonstrated coexpression of EPOR and βCR at the RNA and protein levels in vivo using a deep second-degree scalding injury mouse model. These results highlight the potential role of rhEPO in the improved treatment of burns patients, which might be crucial for the development of innovative new therapy regimes.Conclusion: Local injection of nanosized rhEPO directly to the injury site rather than systemic administration for deep second-degree scalding injuries achieved complete skin regeneration with conical and hair follicle structure via combined expression of EPOR and βCR.Keywords: burns, nanosize, common β subunit, erythropoietin, receptor, local injection