Impaired Wound Healing (impaired + wound_healing)

Distribution by Scientific Domains


Selected Abstracts


Delivery of a Growth Factor Fusion Protein Having Collagen-Binding Activity to Wound Tissues

ARTIFICIAL ORGANS, Issue 2 2003
Tetsuya Ishikawa
Abstract: Recently, we established a collagen-binding growth factor consisting of epidermal growth factor and the fibronectin collagen-binding domain (FNCBD-EGF). FNCBD-EGF is a biologically active fusion protein that could stably bind to collagen materials, and exert its growth factor activity even after collagen binding. In this study, we investigated the concept that FNCBD moiety with high collagen affinity may enhance the effective local concentration of EGF at the site of administration in the following tissues: skin wounds, catheter-injured arteries, and hind limb muscles. In an animal model of impaired wound healing, application of FNCBD-EGF in combination with collagen gel induced granulation tissue formation in the wounds due to its sustained retention. In the injured artery, infused FNCBD-EGF remained bound to collagen exposed on the injured tissues even after blood circulation was restored. Injection of the fusion protein into the hind limbs revealed that our delivery system was effective for direct administration to muscular tissue. [source]


Curcumin differentially regulates TGF-,1, its receptors and nitric oxide synthase during impaired wound healing

BIOFACTORS, Issue 1-2 2002
Haresh Mani
Abstract Wound healing is a highly ordered process, requiring complex and coordinated interactions involving peptide growth factors of which transforming growth factor-beta (TGF-,) is one of the most important. Nitric oxide is also an important factor in healing and its production is regulated by inducible nitric oxide synthase (iNOS). We have earlier shown that curcumin (diferuloylmethane), a natural product obtained from the plant Curcuma longa, enhances cutaneous wound healing in normal and diabetic rats. In this study, we have investigated the effect of curcumin treatment by topical application in dexamethasone-impaired cutaneous healing in a full thickness punch wound model in rats. We assessed healing in terms of histology, morphometry, and collagenization on the fourth and seventh days post-wounding and analyzed the regulation of TGF-,1, its receptors type I (tIrc) and type II (tIIrc) and iNOS. Curcumin significantly accelerated healing of wounds with or without dexamethasone treatment as revealed by a reduction in the wound width and gap length compared to controls. Curcumin treatment resulted in the enhanced expression of TGF-,1 and TGF-, tIIrc in both normal and impaired healing wounds as revealed by immunohistochemistry. Macrophages in the wound bed showed an enhanced expression of TGF-,1 mRNA in curcumin treated wounds as evidenced by in situ hybridization. However, enhanced expression of TGF-, tIrc by curcumin treatment observed only in dexamethasone-impaired wounds at the 7th day post-wounding. iNOS levels were increased following curcumin treatment in unimpaired wounds, but not so in the dexamethasone-impaired wounds. The study indicates an enhancement in dexamethasone impaired wound repair by topical curcumin and its differential regulatory effect on TGF-,1, it's receptors and iNOS in this cutaneous wound-healing model. [source]


Granulocyte/macrophage colony-stimulating factor treatment of human chronic ulcers promotes angiogenesis associated with de novo vascular endothelial growth factor transcription in the ulcer bed

BRITISH JOURNAL OF DERMATOLOGY, Issue 1 2006
F. Cianfarani
Summary Background, Granulocyte/macrophage colony-stimulating factor (GM-CSF), a cytokine with pleiotropic functions, has been successfully employed in the treatment of chronic skin ulcers. The biological effects underlying GM-CSF action in impaired wound healing have been only partly clarified. Objectives, To investigate the effects of GM-CSF treatment of chronic venous ulcers on lesion vascularization and on the local synthesis of the angiogenic factors vascular endothelial growth factor (VEGF) and placenta growth factor (PlGF). Methods, Patients with nonhealing venous leg ulcers were treated with intradermal injection of recombinant human GM-CSF, and biopsies were taken at the ulcer margin before and 5 days after administration. Wound vascularization was analysed by immunohistochemistry using antiplatelet endothelial cell adhesion molecule-1/CD31 and anti-,-smooth muscle actin antibodies. VEGF and PlGF transcription was assessed by in situ hybridization. To identify the cell populations transcribing VEGF within the ulcer bed, the VEGF hybridization signal was correlated with the immunostaining for different cell type markers on serial sections. Direct induction of VEGF transcription by GM-CSF was investigated in GM-CSF-treated cultured macrophages and keratinocytes. Results, Blood vessel density was significantly increased in the ulcer bed following GM-CSF treatment. VEGF transcripts were localized in keratinocytes at the ulcer margin both before and after GM-CSF treatment, whereas a VEGF hybridization signal was evident within the ulcer bed only following administration. PlGF mRNA was barely detectable in keratinocytes at the ulcer margin and was not visibly increased after treatment. Unlike VEGF, a specific PlGF hybridization signal could not be detected in cells within the ulcer following GM-CSF administration. Monocytes/macrophages were the main cell population transcribing VEGF after GM-CSF treatment. In vitro analysis demonstrated that VEGF transcription can be directly stimulated by GM-CSF in a differentiated monocytic cell line, but not in keratinocytes. Conclusions, Our data show that increased vascularization is associated with GM-CSF treatment of chronic venous ulcers and indicate that inflammatory cell-derived VEGF may act as an angiogenic mediator of the healing effect of GM-CSF in chronic ulcers. [source]


A case of focal dermal hypoplasia (Goltz) syndrome with exophytic granulation tissue treated by curettage and photodynamic therapy

CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 2 2006
R. Mallipeddi
Summary Focal dermal hypoplasia (Goltz) syndrome is a rare genetic disorder characterized by cutaneous, ectodermal and mesodermal defects. We present a case in which painful, exophytic granulation tissue has been the main symptom over the past 15 years. After unsatisfactory results with a number of treatment modalities including topical steroids, silver-nitrate applications, cryotherapy, curettage, excision and pulsed-dye laser, we achieved significant benefit with curettage in combination with photodynamic therapy. Although impaired wound healing has been described in focal dermal hypoplasia, this is, to our knowledge, the first time that pyogenic granuloma-like lesions have been reported. [source]