Accelerate Burn Wound Healing Research Articles

Recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) could accelerate burn wound healing in hamster skin

Burns are one of the most devastating forms of trauma and wound healing is a complex and multicellular process, which is executed and regulated by signaling networks involving numerous growth factors, cytokines, and chemokines. Recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) was specifically produced from rice cell culture through use of a recombinant technique in our laboratory. The effect of rhGM-CSF on promotion of deep second-degree burn wound healing on the back skin of a hamster model was evaluated through a randomized and double-blind trial. As macroscopic results, hamster skins of the experimental groups showed earlier recovery by new epidermis than the control groups. Immunohistochemical reactions of proliferating cell nuclear antigen and transforming growth factor-β1, which are indicators of cell proliferation, were more active in the experimental group, compared with the control group. On electron microscopy, basal cells in the epidermis of the experimental group showed oval nuclei, prominent nucleoli, numerous mitochondria and abundant free ribosomes. In addition, fibroblasts contained well-developed rough endoplasmic reticulum with dilated cisternae. Bundles of collagen fibrils filled the extracellular spaces. Particularly, ultrastructural features indicating active metabolism for regeneration of injured skin at 15 days after burn injury, including abundant euchromatin, plentiful free ribosomes, and numerous mitochondria, were observed. These findings suggest that use of rhGM-CSF could result in accelerated deep second-degree burn wound healing in animal models.

Gelam (Melaleucaspp.) Honey-Based Hydrogel as Burn Wound Dressing

A novel cross-linked honey hydrogel dressing was developed by incorporating Malaysian honey into hydrogel dressing formulation, cross-linked and sterilized using electron beam irradiation (25 kGy). In this study, the physical properties of the prepared honey hydrogel and its wound healing efficacy on deep partial thickness burn wounds in rats were assessed. Skin samples were taken at 7, 14, 21, and 28 days after burn for histopathological and molecular evaluations. Application of honey hydrogel dressings significantly enhanced (P < 0.05) wound closure and accelerated the rate of re-epithelialization as compared to control hydrogel and OpSite film dressing. A significant decrease in inflammatory response was observed in honey hydrogel treated wounds as early as 7 days after burn (P < 0.05). Semiquantitative analysis using RT-PCR revealed that treatment with honey hydrogel significantly (P < 0.05) suppressed the expression of proinflammatory cytokines (IL-1α, IL-1β, and IL-6). The present study substantiates the potential efficacy of honey hydrogel dressings in accelerating burn wound healing.

β-lapachone accelerates the recovery of burn-wound skin.

β-lapachone is a quinone of lapachol extracted from the bark of lapacho tree. Recent findings demonstrated that punched skin wounds of mice healed faster with β-lapachone treatment. The present study investigates the effects of β-lapachone on burn-wound skin of C57BL/6 mice injured by a 100 °C iron stick. Our results indicated that wounds treated with β-lapachone recovered faster than those treated with control ointment containing no β-lapachone. On the third day after burning, the area of β-lapachone treated-wound was 30% smaller than wound treated with control ointment. H&E and immunohistochemistry staining showed that burn-wound skin treated with ointment containing β-lapachone healed faster in its epidermis, dermis, and underlying connective tissues with more macrophages appeared than those treated with control ointment alone. RAW264.7 cell, a macrophage-like cell line derived from BALB/C mice, was used as a model for scrutinizing the effect of β-lapachone on macrophages. We found that the proliferation and the secretion of EGF and VEGF by macrophages were higher in cultures treated with β-lapachone and that ß-lapachone can also increase the release of EGF with TNF-α pretreatment. We conclude that β-lapachone plays an important role in accelerating burn wound healing, and that β-lapachone not only can raise the proliferation of macrophages but also increase the release of VEGF from macrophages.

Enhancing effects of a chromone glycoside, eucryphin, isolated from Astilbe rhizomes on burn wound repair and its mechanism

We previously reported that three compounds isolated from Astilbe thunbergii rhizomes accelerated burn wound healing. Among the three substances, eucryphin enhanced burn wound healing most strongly; however, the biological mechanisms of eucryphin are not yet well understood and here we examined the effects on chemokine, growth factor, and cytokine productions in in vivo and in vitro experiments. We have set burn wounds on the backs of mice and topically applied either vehicle alone or vehicle containing low doses of eucryphin to the burn wound. We examined the effects of eucryphin on chemokine, cytokine, and growth factor production at the wound site and in various cells. Eucryphin (10(-4) to 10(-8)% ointment) facilitated burn wound repair compared to the vehicle control. Eucryphin (100 ng per wound) increased IL-1beta, MCP-1, VEGF, and TGF-beta1 levels in the exudates from the wound area. Eucryphin increased VEGF, TGF-beta1, and HIF-1alpha expression levels in keratinocytes. These findings suggest that the enhancement of burn wound healing by eucryphin might be due to promotional angiogenesis during skin wound repair as a result of the stimulation of VEGF and TGF-beta1 production caused by the increase in HIF-1alpha expression in keratinocytes.

Effect of Therapy with Recombinant Human Growth Hormone on Insulin-Like Growth Factor System Components and Serum Levels of Biochemical Markers of Bone Formation in Children After Severe Burn Injury

Burn injury in children is associated with low bone formation and long-term bone loss. Because recombinant human GH (rHGH) may accelerate burn wound healing, and because rHGH increases bone formation and density in GH-deficient patients, we studied the short-term effects of rHGH on bone fomation, reflected by osteocalcin and type I procollagen propeptide levels in a randomized, double-blind, placebo-controlled study. Nineteen patients were enrolled and received either rHGH (0.2 mg/kg.day) or an equal volume of saline. Mean burn size and age were not different between the groups, and test substances were given from admission to time of wound healing (mean: 43 +/- 22 days). At wound healing, serum levels of insulin-like growth factor (IGF)-1 and IGF binding protein (IGFBP)-3 in the rHGH group rose to mean values of 229% and 187% of the respective means of the placebo group (P < 0.025). Serum osteocalcin concentrations remained below normal in both groups, and type I procollagen propeptide levels achieved a low normal level IGFBR-4 levels were twice that of normal on admission and doubled further at wound healing; IGFBP-5 levels were low on admission but rose to normal at wound healing. We conclude that large doses of rHGH were ineffective in improving disordered bone formation despite increasing serum IGF-1 and IGFBP-3. The rHGH-independent rise in serum levels of the inhibitory binding protein IGFBP-4 suggests a mechanism by which improved bone formation is prevented despite successful elevation of IGF-1 and IGFBP-3 in the burned child.