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Heinz Redl - One of the best experts on this subject based on the ideXlab platform.
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Establishment of Vascular Networks in Biochips Using Co-cultures of Adipose Derived Stem Cells and Endothelial Cells in a 3D Fibrin Matrix
IFMBE Proceedings, 2020Co-Authors: Michaela Purtscher, Heinz Redl, Wolfgang Holnthoner, Mario Rothbauer, Peter ErtlAbstract:The development of novel vascularization strategies for tissue constructs is still one of the major challenges in tissue engineering and regeneration. In the present study we investigate the establishment of vascular networks in the absence and presence of fluid flow conditions using a microfluidic co-culture system. In the presented configuration adipose derived stem cells (ASCs) and human umbilical vein cells (HUVEC) are embedded within a 3D Fibrin Matrix to study accumulation and depletion of ASCs secreted paracrine pro-angiogenic factors on vascular tube formation. Initial experiments using fluorescently labelled bovine serum albumin confirmed rapid transport of biomolecules within the Fibrin Matrix over a distance of various millimeters. Results using 3D co-cultures showed that even in the presence of low fluid mechanical shear forces of 0.025 dyn/mm2 the onset and maturation of vascular endothelial networks formation were significantly affected, leading to altered tube size and tube length.
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adipose derived stem cells induce vascular tube formation of outgrowth endothelial cells in a Fibrin Matrix
Journal of Tissue Engineering and Regenerative Medicine, 2015Co-Authors: Wolfgang Holnthoner, Karin Hohenegger, Annamaria Husa, Severin Muehleder, Alexandra Meinl, Anja Peterbauerscherb, Heinz RedlAbstract:Vascularization of engineered tissues is one of the current challenges in tissue engineering. Several strategies aim to generate a prevascularized scaffold which can be implanted at sites of injury or trauma. Endothelial cells derived from peripheral blood (outgrowth endothelial cells, OECs) display promising features for vascular tissue engineering, including their autologous nature, capacity for proliferation and ability to form mature vessels. In this study we investigated the ability of OECs to form vascular structures in co-culture with adipose-derived stem cells (ASCs) in a Fibrin Matrix. Using microcarrier beads coated with OECs, we showed ingrowth of endothelial cells in the Fibrin scaffold. Furthermore, co-cultures with ASCs induced vessel formation, as evidenced by immunostaining for CD31. The degradation of Fibrin is at least in part mediated by expression of Matrix metalloproteinase-14. Moreover, we showed OEC/ASC-induced vessel-like structure formation even in the absence of microcarrier beads, where increasing amounts of ASCs resulted in a denser tubular network. Our data add new insights into co-culture-induced vessel formation of outgrowth endothelial cells within a Fibrin Matrix in an autologous system. Copyright © 2012 John Wiley & Sons, Ltd.
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bmp 2 but not vegf or pdgf in Fibrin Matrix supports bone healing in a delayed union rat model
Journal of Orthopaedic Research, 2012Co-Authors: Martin Kaipel, Paul Slezak, Sebastian Schutzenberger, Arthur Schultz, James L Ferguson, Tatjana J Morton, Martijn Van Griensven, Heinz RedlAbstract:Treatment of delayed bone healing and non-unions after fractures, osteotomies or arthrodesis still is a relevant clinical challenge. Artificially applied growth factors can increase bone healing and progressively gain importance in clinical routine. The aim of this study was to determine the effects of rhPDGF-BB, rhVEGF-165, and rhBMP-2 in Fibrin Matrix on bone healing in a delayed-union rat model. Thirty-seven rats underwent a first operation where a standardized femoral critical size defect was created. A silicone spacer was implanted to impair vascularization within the defect. At 4 weeks the spacer was removed in a second operation and rhPDGF-BB, rhVEGF-165, or rhBMP-2 were applied in a Fibrin clot. Animals in a fourth group received a Fibrin clot without growth factors. At 8 weeks Fibrin bound rhBMP-2 treated animals showed a significantly increased union rate and bone volume within the defect compared to the other groups. Single application of Fibrin bound rhPDGF-BB and rhVEGF-165 failed to increase bone healing in our atrophic non-union model. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1563–1569, 2012
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in vitro adipogenesis of adipose derived stem cells in 3d Fibrin Matrix of low component concentration
Journal of Tissue Engineering and Regenerative Medicine, 2012Co-Authors: Anja Peterbauerscherb, Heinz Redl, Martin Danzer, Christian Gabriel, M Van Griensven, Susanne WolbankAbstract:This study evaluated the suitability of adipose-derived stem cells (ASCs) combined with Fibrin Matrix of variable composition for adipose tissue-equivalent formation in vitro. Therefore, undifferentiated ASCs were embedded in Fibrin clots composed of 2 IU/ml thrombin and Fibrinogen of varying concentrations (6.25, 12.5 and 25 mg/ml) and kept under control or adipogenic conditions. Fibrin–cell composites were evaluated by scanning electron microscopy, live/dead staining, lactate-dehydrogenase (LDH) assay, quantitative PCR for the adipogenic markers fatty acid binding protein 4 (FABP4), peroxisome proliferative activated receptor-γ (PPARγ) and leptin, leptin ELISA and oil red O staining. Cells were found homogeneously distributed throughout the clot. Their number increased to day 7 (up to 3.62-fold median) and decreased thereafter until day 28. The proliferation was unaffected by Fibrinogen concentration in the control. Adipogenic conditions generally yielded higher cell numbers, which were in addition increasing with increasing Fibrinogen concentrations. FABP4, PPARγ and leptin mRNA expression was strongly upregulated by adipogenic medium, which was confirmed by the levels of leptin secretion and lipid vesicles formation demonstrated by oil red O staining. When embedded in 25 mg/ml Fibrinogen clots, ASCs showed the highest expression levels of FABP4 (up to 629.0-fold), PPARγ (up to 1.6-fold) and leptin (up to 57.9-fold), corroborated by significantly elevated leptin secretion (median 33.29 ng/ml) on day 14. Constructs composed of Fibrin Matrix of low component concentrations—allowing homogeneous cell distribution—with ASCs should represent a suitable strategy for adipose tissue formation in vivo. Copyright © 2011 John Wiley & Sons, Ltd.
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BMP‐2 but not VEGF or PDGF in Fibrin Matrix supports bone healing in a delayed‐union rat model
Journal of Orthopaedic Research, 2012Co-Authors: Martin Kaipel, Paul Slezak, Sebastian Schutzenberger, Arthur Schultz, James L Ferguson, Tatjana J Morton, Martijn Van Griensven, Heinz RedlAbstract:Treatment of delayed bone healing and non-unions after fractures, osteotomies or arthrodesis still is a relevant clinical challenge. Artificially applied growth factors can increase bone healing and progressively gain importance in clinical routine. The aim of this study was to determine the effects of rhPDGF-BB, rhVEGF-165, and rhBMP-2 in Fibrin Matrix on bone healing in a delayed-union rat model. Thirty-seven rats underwent a first operation where a standardized femoral critical size defect was created. A silicone spacer was implanted to impair vascularization within the defect. At 4 weeks the spacer was removed in a second operation and rhPDGF-BB, rhVEGF-165, or rhBMP-2 were applied in a Fibrin clot. Animals in a fourth group received a Fibrin clot without growth factors. At 8 weeks Fibrin bound rhBMP-2 treated animals showed a significantly increased union rate and bone volume within the defect compared to the other groups. Single application of Fibrin bound rhPDGF-BB and rhVEGF-165 failed to increase bone healing in our atrophic non-union model. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:1563–1569, 2012
Kris Kieswetter - One of the best experts on this subject based on the ideXlab platform.
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effects of negative pressure wound therapy on cellular energetics in fibroblasts grown in a provisional wound Fibrin Matrix
Wound Repair and Regeneration, 2009Co-Authors: Amy Mcnulty, Marisa Schmidt, Teri D Feeley, Patricia A Villanueva, Kris KieswetterAbstract:Negative pressure wound therapy (NPWT) using reticulated open cell foam dressing (ROCF) is effective for treatment of recalcitrant wounds; however, the effects of this therapy on cellular metabolism remain to be elucidated. The effect of two different subatmospheric pressure applications on the cell energetics of human fibroblasts grown in a 3D Fibrin Matrix was studied using two different pressure-manifolding materials, an ROCF or gauze under suction (GUS). It was found that levels of cytochrome c oxidase, energy charge, and adenosine triphosphate/adenosine diphosphate were significantly increased following the application of NPWT using ROCF vs. GUS (p < 0.05). Increases in these parameters likely reflect an improved energetic status. In addition, levels of transforming growth factor-β and platelet-derived growth factor (α and isoforms) were significantly increased (80 and 53%, respectively; p < 0.05) over static control cultures following treatment with NPWT using ROCF but not following GUS. These growth factors are known to be important during wound healing. Clearly, both the material used as the dressing to manifold the subatmospheric pressure and the pressure used have a dramatic effect on cellular response.
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effects of negative pressure wound therapy on fibroblast viability chemotactic signaling and proliferation in a provisional wound Fibrin Matrix
Wound Repair and Regeneration, 2007Co-Authors: Amy Mcnulty, Marisa Schmidt, Teri D Feeley, Kris KieswetterAbstract:Vacuum Assisted Closure® brand Negative Pressure Wound Therapy (V.A.C.® NPWT) has been shown to be an effective therapeutic option for the treatment of recalcitrant wounds; however, the mechanism of action at the cellular level remains to be elucidated. Here, we examined the effects of negative pressure wound therapy, manifolded with two different dressings, on fibroblast viability, chemotactic signaling, and proliferation in a Fibrin clot Matrix. Fibroblasts were grown in a three-dimensional Fibrin Matrix and were treated for 48 hours with either V.A.C.® NPWT and GranuFoam ® Dressing, or with gauze under suction, or as static controls without negative pressure or dressings. Cells treated by gauze under suction showed significantly greater cell death and stimulated less migration and proliferation than static and V.A.C.® NPWT-treated cells (p < 0.05). Apoptosis was also significantly higher in gauze under suction than in static treatments. These results indicate that the dressing material has a significant effect on cell response following negative pressure wound therapy. The ability to support cell growth, stimulate chemotaxis, and proliferation without increasing apoptosis may provide an insight into the mechanisms of action of V.A.C.® NPWT.
Pieter Koolwijk - One of the best experts on this subject based on the ideXlab platform.
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molecular weight Fibrinogen variants determine angiogenesis rate in a Fibrin Matrix in vitro and in vivo
Journal of Thrombosis and Haemostasis, 2006Co-Authors: Eric L Kaijzel, Victor W M Van Hinsbergh, Pieter Koolwijk, M G M Van Erck, M P M De MaatAbstract:Background: During wound repair, Fibrin acts both as a barrier to prevent blood loss and as a temporary Matrix for the invasion and ingrowth of endothelial and tissue cells. A well-controlled angiogenesis process in the Fibrinous exudate Matrix is crucial for optimal wound healing. The composition and structure of the Fibrin Matrix are important determinants of the invasion of endothelial cells and capillary-tube formation into the Matrix. Objective: Fibrinogen circulates in a high and low molecular weight form (HMW and LMW, respectively) and the purpose of this study was to investigate how Fibrin matrices from these naturally occurring Fibrinogen variants influence angiogenesis. Angiogenesis was studied using an in vitro model in which human microvascular endothelial cells (hMVEC) were cultured on three-dimensional Fibrin matrices from different Fibrinogen forms, and using two in vivo mouse models. Results: The in vitro angiogenesis in an HMW-Fibrin Matrix shows increased cell and tubular structure ingrowth compared with unfractionated Fibrin Matrix (median increase 58%, range 46-234%). The ingrowth of tubular structures in an LMW-Fibrin matrices is decreased when compared with unfractionated Fibrin (median decrease 70%, range 67-100%). Similar results were observed for in vivo angiogenesis. Conclusions: The naturally occurring Fibrinogen variants HMW- and LMW-Fibrin modulate the angiogenic capacity of endothelial cells in Fibrin matrices. The different effects of the molecular weight Fibrinogen variants provide further insight in the Matrix characteristics in angiogenesis and could possibly be applied in the context of tissue engineering and wound healing. © 2006 International Society on Thrombosis and Haemostasis.
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role of Fibrin Matrix in angiogenesis
Annals of the New York Academy of Sciences, 2006Co-Authors: Victor W M Van Hinsbergh, Annemie Collen, Pieter KoolwijkAbstract:Abstract: Angiogenesis, the formation of new blood vessels from existing vessels, plays an important role during development. In the adult, it is limited to the female reproductive system and to tissue repair and pathological conditions. Repair associated angiogenesis is usually accompanied by the presence of inflammatory cells, vascular leakage, and Fibrin deposition. The temporary Fibrin Matrix acts, not only as a sealing Matrix, but also as a scaffolding for invading leukocytes and endothelial cells during tissue repair. We have used a three-dimensional Fibrin Matrix to study the outgrowth of human microvascular endothelial cells in capillary-like tubular structures. This process is induced by the simultaneous addition of an angiogenic growth factor (bFGF or VEGF) and the cytokine TNFα, and is enhanced by hypoxia. It involves proteolytic activities, in particular cell bound urokinase/plasmin and Matrix metalloproteinase activities. Modulation of the Fibrin structure markedly affects the extent and stability of capillary tube formation in vitro. Preparation of Fibrin at different pH (7.0–7.8) or crosslinking of the Fibrin Matrix induces differences in Fibrin Matrix rigidity and structure. This is accompanied by a change in capillary ingrowth. Heparins, in particular low molecular weight heparins, modulate the Fibrin structure and by this action affect angiogenesis in vitro. A mutant FibrinogenNieuwegein, which lacks the terminal part of the Aα chain of Fibrin harboring an RGD sequence and the transglutaminase sequence, provided additional evidence that the structure of Fibrin is an important determinant for angiogenesis. These findings may have impact on improving wound healing and on influencing angiogenesis in malignancies with a Fibrinous stroma.
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Aminopeptidase inhibitor bestatin stimulates microvascular endothelial cell invasion in a Fibrin Matrix
Thrombosis and Haemostasis, 2003Co-Authors: Yvette Van Hensbergen, Victor W M Van Hinsbergh, Henk J. Broxterman, Erna Peters, Sareena Rana, Yvonne W. Elderkamp, Pieter KoolwijkAbstract:The aminopeptidase inhibitor bestatin has been shown to have anti-angiogenic effects in a number of model systems. These effects are thought to result from inhibition of CD13 activity. Because tumor angiogenesis can evolve in a Fibrin-rich stroma Matrix we have studied for the first time the effects of bestatin on microvascular endothelial capillary-like tube formation in a Fibrin Matrix. Bestatin enhanced the formation of capillary-like tubes dose-dependently. Its effects were apparent at 8 µM; the increase was 3.7-fold at 125 µM; while high concentrations (>250 µM), that were shown to have anti-angiogenic effects in other systems, caused extensive Matrix degradation. Specific CD13-blocking antibodies WM15 and MY-7, and the aminopeptidase inhibitors amastatin and actinonin also enhanced capillary- like tube formation (maximally 1.5-fold), but these effects did not reach statistical significance. The effect of bestatin was not due to a change in uPAR availability because the relative involvement of the u-PA/u-PAR activity was not altered by bestatin. In view of the present findings we hypothesize that aminopeptidases other than CD13 predominantly contribute to the observed pro-angiogenic effect of bestatin in a Fibrin Matrix. The identification of this novel effect of bestatin is important in the light of the proposed use of bestatin as anti-angiogenic and/or anti-tumor agent.
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collagen type 1 retards tube formation by human microvascular endothelial cells in a Fibrin Matrix
Angiogenesis, 2002Co-Authors: Marielle E Kroon, Victor W M Van Hinsbergh, Marianke L J Van Schie, Bea Van Der Vecht, Pieter KoolwijkAbstract:Angiogenesis, or the formation of new microvessels, is often encountered in pathological situations. A Fibrinous exudate can often act as a temporary Matrix for the ingrowth of these new microvessels. This Matrix consists mainly of Fibrin, but is mingled with other plasma components and interstitial collagen fibres. In vitro, capillary-like tube formation can be mimicked by exposing human microvascular endothelial cells (hMVECs), seeded on top of a three-dimensional Fibrin Matrix, to an angiogenic growth factor (e.g. fibroblast growth factor (FGF)-2) and the cytokine tumour necrosis factor (TNF)-α. Plasmin activity is required in this process. We investigated whether the angiogenic potential of hMVECs was altered by the presence of collagen. The addition of type I collagen to Fibrin matrices dose-dependently inhibited tube-formation. Tube-formation in these Fibrin/collagen matrices by hMVECs required Matrix metalloprotease (MMP) activity, as well as plasmin activity. On a pure collagen type I Matrix, hMVECs were not able to form tube-like structures in the Matrix but formed sprouts. This sprouting required MMP activity and was, in contrast to the tube-like structures in a Fibrin Matrix, not influenced by hypoxia. These data indicate that the interaction between endothelial cells and different Matrix components is of importance for the angiogenic potential of these cells.
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Urokinase receptor expression on human microvascular endothelial cells is increased by hypoxia: implications for capillary-like tube formation in a Fibrin Matrix
Blood, 2000Co-Authors: Marielle E Kroon, Pieter Koolwijk, Bea Van Der Vecht, Victor W M Van HinsberghAbstract:Abstract Hypoxia stimulates angiogenesis, the formation of new blood vessels. This study evaluates the direct effect of hypoxia (1% oxygen) on the angiogenic response of human microvascular endothelial cells (hMVECs) seeded on top of a 3-dimensional Fibrin Matrix. hMVECs stimulated with fibroblast growth factor–2 (FGF-2) or vascular endothelial growth factor (VEGF) together with tumor necrosis factor–α (TNF-α) formed 2- to 3-fold more tubular structures under hypoxic conditions than in normoxic (20% oxygen) conditions. In both conditions the in-growth of capillary-like tubular structures into Fibrin required cell-bound urokinase-type plasminogen activator (uPA) and plasmin activities. The hypoxia-induced increase in tube formation was accompanied by a decrease in uPA accumulation in the conditioned medium. This decrease in uPA level was completely abolished by uPA receptor-blocking antibodies. During hypoxic culturing uPA receptor activity and messenger RNA (mRNA) were indeed increased. This increase and, as a consequence, an increase in plasmin formation contribute to the hypoxia-induced stimulation of tube formation. A possible contribution of VEGF-A to the increased formation under hypoxic conditions is unlikely because there was no increased VEGF-A expression detected under hypoxic conditions, and the hypoxia-induced tube formation by FGF-2 and TNF-α was not inhibited by soluble VEGFR-1 (sVEGFR-1), or by antibodies blocking VEGFR-2. Furthermore, although the αv-integrin subunit was enhanced by hypoxia, blocking antibodies against αvβ3- and αvβ5-integrins had no effect on hypoxia-induced tube formation. Hypoxia increases uPA association and the angiogenic response of human endothelial cells in a Fibrin Matrix; the increase in the uPA receptor is an important determinant in this process.
Anthony P. Sclafani - One of the best experts on this subject based on the ideXlab platform.
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platelet rich Fibrin Matrix prfm for androgenetic alopecia
Facial Plastic Surgery, 2014Co-Authors: Anthony P. SclafaniAbstract:The objective of this study was to determine the effect of platelet-rich Fibrin Matrix (PRFM) treatment on androgenetic alopecia. Prospective cohort study of 15 (9 male and 6 female) subjects with androgenetic alopecia for at least 1 year who were treated with intradermal injections of autologous PRFM three times on a monthly basis. Hair density indices were measured in triplicate in the same area of the scalp before the treatment and 1, 2, 3 and 6 months after initial treatment. Hair density index (HDI) measurements were obtained and compared with pretreatment values for each subject. After a series of three intradermal PRFM injections, hair density indices increased significantly at 2 (47.4 ± 22.7%, p = 0.0031) and 3 (106.4 ± 56.9%, p = 0.0277, paired t -test) months after the initial treatment, and approached statistical significance at 6 months (75.1 ± 46.82%, p = 0.0606) after the initial treatment. Patients who achieved greater than 25% increase in HDI by 2 months after the initial treatment were more likely to have greater than 25% improvement at 6 months after the initial treatment (100 vs. 16.7%, p = 0.0476). Androgenetic alopecia affects a significant number of both men and women. A series of intradermal injections of autologous PRFM increased the HDI in patients with androgenetic alopecia at 2 and 3 months after initial treatment; this improvement approached statistical significance at 6 months after initiating treatment. Autologous PRFM injections may be a valuable treatment for androgenetic alopecia, particularly in cases with mild hair loss. The level of evidence is level 2.
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Platelet-rich Fibrin Matrix for facial plastic surgery.
Facial Plastic Surgery Clinics of North America, 2012Co-Authors: Anthony P. Sclafani, Masoud SamanAbstract:Platelets are known primarily for their role in hemostasis, but there is increasing interest in the effect of platelets on wound healing. Platelet isolates such as platelet-rich plasma have been advocated to enhance and accelerate wound healing. This article describes the use of a novel preparation, platelet-rich Fibrin Matrix (PRFM), for facial plastic surgery applications such as volume augmentation, fat transfer supplementation, and as an adjunct to open surgical procedures.
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induction of dermal collagenesis angiogenesis and adipogenesis in human skin by injection of platelet rich Fibrin Matrix
Archives of Facial Plastic Surgery, 2012Co-Authors: Anthony P. Sclafani, Steven A MccormickAbstract:Objective To evaluate the histological changes induced in human skin by injection of autologous platelet-rich Fibrin Matrix (PRFM). Methods Four healthy adult volunteers were included in the study. Platelet-rich Fibrin Matrix was prepared from 9 mL of autologous blood using a proprietary system (Selphyl; Aesthetic Factors, Wayne, New Jersey) and injected into the deep dermis and immediate subdermis of the upper arms of subjects. Full-thickness skin biopsy specimens were taken from the treated areas over a 10-week period, and the specimens were processed for histological evaluation. Results Findings from histological examination supported the clinical observation of soft-tissue augmentation. As early as 7 days after treatment, activated fibroblasts and new collagen deposition were noted and continued to be evident throughout the course of the study. Development of new blood vessels was noted by 19 days; also at this time, intradermal collections of adipocytes and stimulation of subdermal adipocytes were noted. These findings became more pronounced over the duration of the study, although the fibroblastic response became much less pronounced. No abnormal mitotic figures were observed at any point, and a very mild chronic inflammatory response was noted only at the earliest time points of the study. Conclusions Injection of PRFM into the deep dermis and subdermis of the skin stimulates a number of cellular changes that can be harnessed for use. Coupled with prior in vitro and in vivo studies, we now have a much clearer picture of the cellular effects of PRFM and its potential uses in facial plastic surgery. Further work is planned to more clearly elucidate the potential role of PRFM in aesthetic and reconstructive surgery. Trial Registration clinicaltrials.gov Identifier: NCT00956020
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Platelet-Rich Fibrin Matrix for Facial Plastic Surgery
Facial Plastic Surgery Clinics of North America, 2012Co-Authors: Anthony P. Sclafani, Masoud SamanAbstract:Platelets are known primarily for their role in hemostasis, but there is increasing interest in the effect of platelets on wound healing. Platelet isolates such as platelet-rich plasma have been advocated to enhance and accelerate wound healing. This article describes the use of a novel preparation, platelet-rich Fibrin Matrix (PRFM), for facial plastic surgery applications such as volume augmentation, fat transfer supplementation, and as an adjunct to open surgical procedures. © 2012 Elsevier Inc.
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safety efficacy and utility of platelet rich Fibrin Matrix in facial plastic surgery
Archives of Facial Plastic Surgery, 2011Co-Authors: Anthony P. SclafaniAbstract:Objective To evaluate the clinical safety and efficacy of the use of autologous platelet-rich Fibrin Matrix (PRFM) in facial plastic surgery. Methods Medical charts of the last 50 patients with at least 3 months of follow-up who were treated by the author with PRFM for aesthetic purposes were reviewed for patient satisfaction, objective clinical results, and adverse events. Results The study cohort of patients was followed up for a mean (SD) of 9.9 (8.0) months (range, 3-30 months). Most patients were treated for deep nasolabial folds, while the volume-depleted midface region, superficial rhytids, and acne scars were other commonly treated areas. The patients underwent an average of 1.6 treatments (range, 1-5 treatments). No patients reported any swelling lasting longer than 5 days, and most noted only minimal bruising lasting for 1 to 3 days. Most patients were satisfied with the results of their treatments, although 1 patient felt that there was limited or no improvement after 2 treatments. Conclusions Autologous PRFM treatment is a well-tolerated, excellent choice for use in the face. Further studies on the precise mechanism of action of PRFM are ongoing.
Amy Mcnulty - One of the best experts on this subject based on the ideXlab platform.
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effects of negative pressure wound therapy on cellular energetics in fibroblasts grown in a provisional wound Fibrin Matrix
Wound Repair and Regeneration, 2009Co-Authors: Amy Mcnulty, Marisa Schmidt, Teri D Feeley, Patricia A Villanueva, Kris KieswetterAbstract:Negative pressure wound therapy (NPWT) using reticulated open cell foam dressing (ROCF) is effective for treatment of recalcitrant wounds; however, the effects of this therapy on cellular metabolism remain to be elucidated. The effect of two different subatmospheric pressure applications on the cell energetics of human fibroblasts grown in a 3D Fibrin Matrix was studied using two different pressure-manifolding materials, an ROCF or gauze under suction (GUS). It was found that levels of cytochrome c oxidase, energy charge, and adenosine triphosphate/adenosine diphosphate were significantly increased following the application of NPWT using ROCF vs. GUS (p < 0.05). Increases in these parameters likely reflect an improved energetic status. In addition, levels of transforming growth factor-β and platelet-derived growth factor (α and isoforms) were significantly increased (80 and 53%, respectively; p < 0.05) over static control cultures following treatment with NPWT using ROCF but not following GUS. These growth factors are known to be important during wound healing. Clearly, both the material used as the dressing to manifold the subatmospheric pressure and the pressure used have a dramatic effect on cellular response.
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effects of negative pressure wound therapy on fibroblast viability chemotactic signaling and proliferation in a provisional wound Fibrin Matrix
Wound Repair and Regeneration, 2007Co-Authors: Amy Mcnulty, Marisa Schmidt, Teri D Feeley, Kris KieswetterAbstract:Vacuum Assisted Closure® brand Negative Pressure Wound Therapy (V.A.C.® NPWT) has been shown to be an effective therapeutic option for the treatment of recalcitrant wounds; however, the mechanism of action at the cellular level remains to be elucidated. Here, we examined the effects of negative pressure wound therapy, manifolded with two different dressings, on fibroblast viability, chemotactic signaling, and proliferation in a Fibrin clot Matrix. Fibroblasts were grown in a three-dimensional Fibrin Matrix and were treated for 48 hours with either V.A.C.® NPWT and GranuFoam ® Dressing, or with gauze under suction, or as static controls without negative pressure or dressings. Cells treated by gauze under suction showed significantly greater cell death and stimulated less migration and proliferation than static and V.A.C.® NPWT-treated cells (p < 0.05). Apoptosis was also significantly higher in gauze under suction than in static treatments. These results indicate that the dressing material has a significant effect on cell response following negative pressure wound therapy. The ability to support cell growth, stimulate chemotaxis, and proliferation without increasing apoptosis may provide an insight into the mechanisms of action of V.A.C.® NPWT.