Intracutaneously injected human adipose tissue-derived stem cells in a mouse model stay at the site of injection.

The aim of this study was to evaluate the local behavior of intracutaneously injected human mesenchymal stem cells from adipose tissue and to determine the safety of a cell-based cutaneous therapy in an animal model.Human mesenchymal stem cells from adipose tissue were labeled with red fluorochrome and were injected intradermally in the paravertebral area in immunodeficient BalbC/nude mice (n = 21). As a control, cell culturemedium was injected in the same fashion on the contralateral paravertebral side. Four weeks, 6 months, and 12 months after the injection, seven mice were examined. In addition to the injected areas, the lungs, kidneys,spleens, and brains were excised and processed for histological evaluation. Serial sections of all the tissues excised were evaluated for adipose tissue-derived stem cells by means of emerging red fluorescent signals.The injected stem cells could be detected throughout the follow-up period of 1-year at the injection site within the dermal and subcutaneous layers. Bar these areas, adipose tissue-derived stem cells were not found in any otherexamined tissue at any point in time. The adipose tissue-derived stem cells showed a slow transition to deeper subcutaneous adipose tissue layers and, in part, a differentiation into adipocytes. No ulceration, inflammation, ortumor induction could be detected.The present study shows that intracutaneously injected human mesenchymal stem cells from adipose tissue stay at the site of injection, survive in vivo for up to 1-year, and partly differentiate into adipocytes. This is a new andvery important finding needed to safely apply therapies based on such stem cells in fat transplants in regenerative medicine.

Abrogation of TGF-beta by antisense oligonucleotides modulates expression of VEGF and increases angiogenic potential in isolated fibroblasts from radiated skin.

The transforming growth factor-beta (TGF-beta) has been identified as an important component of wound healing. Recent developments in molecular therapy offer good prospects for the modulation of wound healing, specifically those targeting TGF-beta. The aim of this study was to analyze the effect of TGF-beta targeting on the expression of angiogenic vascular endothelial growth factor (VEGF), a key regulator of angiogenesis and in vitro angiogenic activity in fibroblasts isolated from radiation-induced chronic dermal wounds. The expression of angiogenic VEGF in tissue samples from radiation-induced chronic dermal wounds was investigated by immunohistochemistry and microarray technique. The effect of TGF-beta targeting using antisense oligonucleotides on the expression of VEGF in isolated fibroblasts was analyzed by ELISA and multiplex RT-PCR. Human endothelial cells (ECs) were grown in conditioned medium produced from the treated fibroblasts. EC migration was measured using a modified Boyden chamber; EC tube formation was analyzed under a light microscope. Immunohistochemical investigation and microarray analysis demonstrated a decreased expression of VEGF protein and mRNA in tissue samples from radiation-induced chronic dermal wounds compared to normal human skin. Antisense TGF-beta oligonucleotide treatment significantly up-regulated VEGF secretion in vitro. Addition of conditioned medium from TGF-beta antisense-treated fibroblasts resulted in an increase in EC cell migration and tube formation. In conclusion, our results demonstrate that TGF-beta antisense oligonucleotide technology may be a potential therapeutic option for stimulation of angiogenesis in radiation-induced dermal wounds.

[Pathogenesis of chronic wounds]. / Pathophysiologie der chronischen Wunde.

Chronic, nonhealing wounds and their therapy are not only a medical problem but a severe economic one as well. Such wounds have a great effect on quality of life. Basic research has enhanced our understanding of the stimulation and inhibition of wound healing and provides the basis for introducing new and innovative treatment methods. This paper reviews the most relevant in- and extrinsic factors that disturb physiologic wound healing to result in chronic nonhealing wounds. In addition, molecular intervention modalities targeting various aspects of wound repair are demonstrated.

TGF-beta antisense oligonucleotides modulate expression of matrix metalloproteinases in isolated fibroblasts from radiated skin.

BACKGROUND: Transforming growth factor-beta (TGF-beta) has been identified as an important component of wound healing. Recent developments in molecular therapy offer exciting prospects for the modulation of wound healing, specifically those targeting TGF-beta. The purpose of this study was to analyze the effect of TGF-beta targeting on the expression of matrix metalloproteinases (MMPs) in fibroblasts isolated from radiation-induced chronic dermal wounds. MATERIALS AND METHODS: The expression of MMPs in tissue samples from radiation-induced chronic dermal wounds was investigated by immunohistochemistry and microarray technique. The effect of TGF-beta targeting using antisense oligonucleotides on the expression of MMPs in isolated fibroblasts was analysed by ELISA and multiplex RT-PCR. RESULTS: Immunohistochemical investigation and microarray analysis demonstrated an increased expression of MMP protein and mRNA in tissue samples from radiation-induced chronic dermal wounds compared to normal human skin. Antisense TGF-beta oligonucleotide treatment significantly down-regulated MMP secretion in vitro. CONCLUSION: TGF-beta antisense oligonucleotide technology may be a potential therapeutic option for the inhibition of proteolytic tissue destruction in radiation-induced chronic wounds.

Long-term nipple shrinkage following augmentation by an autologous rib cartilage transplant in free DIEP-flaps.

Aesthetically pleasing nipple-areola reconstruction is a satisfying part of a two-stage breast reconstruction. The up to 50% [Banducci DR, Le TK, Hughes KC. Long-term follow-up of a modified Anton-Hartrampf nipple reconstruction. Ann Plast Surg 1999;43(5):467-9; discussion 469-70] postoperative shrinkage following a conventional nipple reconstruction is a well-known problem. Augmentation of the nipple with autologous banked cartilage seems to be a promising solution. From 2000-2003, 17 patients underwent a nipple-areola-complex reconstruction following secondary breast reconstruction using free perforator flaps. The rib cartilage harvested during the preparation of the internal thoracic vessels was banked subcutaneously and six months later replanted under the 'arrow flap' after contouring it in a 'mushroom' shape. One year later the shrinkage of the nipple in comparison to the intraoperative status was measured. In addition, patients were asked about their personal palpation impression and the aesthetic outcome. The average height decreased one year postoperatively about 25%. Thirteen of 17 patients judged the aesthetic outcome as very good, 16 nipples healed without cartilage protrusion and no patient felt discomfortable stiffness of the nipple. Our concept of a nipple augmentation with rib cartilage improves the projection and allows a more correct judgement of the later nipple shrinkage. We consider this technique to be an aesthetically satisfying and safe method, which could be used with any kind of breast reconstruction.

The impact of vacuum freeze-drying on collagen sponges after gas plasma sterilization.

The sterilization of porous collagen sponges remains a challenging procedure. Gamma irradiation denatures collagen, resulting in dramatic changes to its structure. Ethylene oxide leaves toxic residues requiring weeks to evaporate. This study investigated the impact on cell behavior of gas plasma treatment when combined with vacuum freeze-drying. The goal of this procedure is to eliminate the molecules of hydrogen peroxide remaining after the sterilization process, together with their decomposition products, from the scaffolds. These molecules hinder the immediate use of the porous designs. Collagen and EDC/NHS-heparinized collagen scaffolds were sterilized with gas plasma. H2O2 released by the collagen specimens was measured by peroxidase test both immediately and also 1 week after the plasma treatment. Further measurements were done 24, 36, 48 and 72 h after vacuum freeze-drying. The activity of these scaffolds was further evaluated in relation to the proliferation, migration and differentiation of human umbilical vein endothelial cells (HUVECs). Both immediately after exposure to gas plasma and also 1 week later, the collagen designs contained significantly higher concentrations of H2O2 than scaffolds having also undergone vacuum freeze-drying. This procedure achieved faster decontamination of the remaining H2O2. Following vacuum freeze-drying, sponges already allowed HUVEC proliferation after 48 h, but in non-lyophilized specimens after gas plasma treatment alone, cell death occurred as early as only 1 week later. These data highlight the advantages of carrying out vacuum freeze-drying following gas plasma sterilization. The results show the substantial impact of sterilization of porous materials made for tissue engineering.