PURPOSE: Human pigmented tissue-engineered skin substitutes represent an advanced therapeutic option to treat skin defects. The inflammatory response is one of the major factors determining integration and long-term survival of such a graft in vivo. The aim of the present study was to investigate the spatiotemporal distribution of host-derived macrophage and granulocyte graft infiltration as well as hypoxia-inducible factor 1 alpha (HIF-1-alpha) expression in a (nu/nu) rat model. METHODS: Keratinocytes, melanocytes, and fibroblasts derived from human skin biopsies were isolated, cultured, and expanded in vitro. Dermal fibroblasts were seeded into collagen type I hydrogels that were subsequently covered by keratinocytes and melanocytes in 5:1 ratio. These pigmented dermo-epidermal skin substitutes were transplanted onto full-thickness skin wounds on the back of immuno-incompetent rats and analyzed at early (1 and 3 weeks) and late (6 and 12 weeks) stages of wound healing. The expression of distinct inflammatory cell markers specific for granulocytes (HIS48) or macrophages (CD11b, CD68), as well as HIF-1-alpha were analyzed and quantified by immunofluorescence microscopy. RESULTS: Our data demonstrate that granulocytes infiltrate the entire graft at 1 week post-transplantation. This was followed by monocyte/macrophage recruitment to the graft at 3-12 weeks. The macrophages were initially restricted to the borders of the graft (early stages), and were then found throughout the entire graft (late stages). We observed a time-dependent decrease of macrophages. Only a few graft-infiltrating granulocytes were found between 6-12 weeks, mostly at the graft borders. A heterogeneous expression of HIF-1-alpha was observed at both early and late wound healing stages. CONCLUSIONS: Our findings demonstrate the spatiotemporal distribution of inflammatory cells in our transplants closely resembles the one documented for physiological wound healing.
PURPOSE:Human pigmented tissue-engineered skin substitutes represent an advanced therapeutic option to treat skin defects. The inflammatory response is one of the major factors determining integration and long-term survival of such a graft in vivo. The aim of the present study was to investigate the spatiotemporal distribution of host-derived macrophage and granulocyte graft infiltration as well as hypoxia-inducible factor 1 alpha (HIF-1-alpha) expression in a (nu/nu) rat model. METHODS: Keratinocytes, melanocytes, and fibroblasts derived from human skin biopsies were isolated, cultured, and expanded in vitro. Dermal fibroblasts were seeded into collagen type I hydrogels that were subsequently covered by keratinocytes and melanocytes in 5:1 ratio. These pigmented dermo-epidermal skin substitutes were transplanted onto full-thickness skin wounds on the back of immuno-incompetent rats and analyzed at early (1 and 3 weeks) and late (6 and 12 weeks) stages of wound healing. The expression of distinct inflammatory cell markers specific for granulocytes (HIS48) or macrophages (CD11b, CD68), as well as HIF-1-alpha were analyzed and quantified by immunofluorescence microscopy. RESULTS: Our data demonstrate that granulocytes infiltrate the entire graft at 1 week post-transplantation. This was followed by monocyte/macrophage recruitment to the graft at 3-12 weeks. The macrophages were initially restricted to the borders of the graft (early stages), and were then found throughout the entire graft (late stages). We observed a time-dependent decrease of macrophages. Only a few graft-infiltrating granulocytes were found between 6-12 weeks, mostly at the graft borders. A heterogeneous expression of HIF-1-alpha was observed at both early and late wound healing stages. CONCLUSIONS: Our findings demonstrate the spatiotemporal distribution of inflammatory cells in our transplants closely resembles the one documented for physiological wound healing.
Authors: Thorsten Cramer; Yuji Yamanishi; Björn E Clausen; Irmgard Förster; Rafal Pawlinski; Nigel Mackman; Volker H Haase; Rudolf Jaenisch; Maripat Corr; Victor Nizet; Gary S Firestein; Hans Peter Gerber; Napoleone Ferrara; Randall S Johnson Journal: Cell Date: 2003-03-07 Impact factor: 41.582
Authors: Agnieszka S Klar; Sinan Güven; Thomas Biedermann; Joachim Luginbühl; Sophie Böttcher-Haberzeth; Claudia Meuli-Simmen; Martin Meuli; Ivan Martin; Arnaud Scherberich; Ernst Reichmann Journal: Biomaterials Date: 2014-03-27 Impact factor: 12.479
Authors: Agnieszka S Klar; Sophie Böttcher-Haberzeth; Thomas Biedermann; Clemens Schiestl; Ernst Reichmann; Martin Meuli Journal: Pediatr Surg Int Date: 2014-02 Impact factor: 1.827
Authors: Agnes S Klar; Katarzyna Michalak-Mićka; Thomas Biedermann; Claudia Simmen-Meuli; Ernst Reichmann; Martin Meuli Journal: Pediatr Surg Int Date: 2017-11-09 Impact factor: 1.827
Authors: Agnes S Klar; Thomas Biedermann; Claudia Simmen-Meuli; Ernst Reichmann; Martin Meuli Journal: Pediatr Surg Int Date: 2016-12-20 Impact factor: 1.827