Burn injury-induced alterations in wound inflammation and healing are associated with suppressed hypoxia inducible factor-1alpha expression

A major complication associated with burn injury is delayed wound healing. While healing of the burn injury site is essential, healing of distal injury sites caused by surgical interventions and other processes also is important. The impact of burn injury on healing of these distal wound sites is not understood clearly. To study this, mice were subjected to major burn injury or a sham procedure. Immediately following, excisional wounds were made on the dorsal surface caudal to the burn site and wound closure was monitored over a 7-d period by planimetry. In a second series of experiments, plasma and excisional wounds were collected for in vitro analysis of cyto- and chemokine levels, L-arginine metabolism, and hypoxia-inducible factor (HIF)-1alpha expression. At 1-7 d post-injury, a significant inflammatory response was evident in both groups, but the healing process was delayed in the burn-injured mice. At 3 d post-injury, wound levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and keratinocyte-derived chemokine were suppressed in the burn group. This difference in the wound inflammatory response was independent of changes in L-arginine metabolism (nitrate levels, inducible nitric oxide synthase expression, arginase activity), but correlated with a marked reduction in HIF-1alpha protein levels. In conclusion, these findings suggest that HIF-1alpha and the inflammatory response play a significant role in wound healing, and reduced levels of HIF-1alpha contribute to the impaired healing response post-burn.     

Changes in human burn fluid biological activity during normal burn healing

The main goal of this work was monitoring the changes occurring in human burn fluid biological activity during normal burn healing. The fluid available in the burn until healing makes a good material for controlling biochemical microenvironment of burn cells. This environment involves factors, such as extracellular matrix proteins and matrix metalloproteinases. In this work our previous studies of the influence of wound and burn fluids on the functional activity of cells were extended to include the effect of burn fluid on fibroblasts and keratinocytes, i. e. human skin cells present in the wound and involved in wound healing. It was shown that human burn fluid biological activity depends on the time that passed after burning, and on the correctness of healing. Migration of human fibroblasts becomes more intensive under the influence of such a fluid independently on the time of fluid sampling. Unlike, keratinocyte migration was inhibited by burn fluid sampled 1-3 days after burning but was enhanced by fluids sampled 6 days following burning. The obtained data are to be necessarily taken into consideration at burn treatment and also at transplantation of cells for healing of wounds of different nature.     

Change in synthetic activity of epidermis cells in rats during burn wound healing under a scab and in liquid environment

One of the problems of burn treatment is a creation of conditions providing most valuable skin rehabilitation. An experimental model of burn wound healing in a 0.9% NaCl solution is proposed. Synthetic activity of rat epidermis cells in the process of burn wound healing under a scab and in liquid environment was studied by luminescent microscopy. The effect of a 0.9% NaCl solution involves an increase of the basal layer cell synthetic activity of regenerating epidermis, and keeping a high level of this activity of hair follicle epithelial cells for a long time. Tissue-preserving effect of the 0.9% NaCl solution on burns healing has been confirmed in these results.     

Pathomorphism of experimental pancreatic necrosis after endolymphatic administration of contrical

Histological and electron microscopic studies of canine pancrease were conducted with biochemical control of pancreatic enzyme activity before and after treatment of experimental hemorrhagic pancreatonecrosis. 30-60 minutes after the disease induction microfocal pancreatonecrosis was revealed, while 6-8 hours later subtotal hemorrhagic pancreatonecrosis with changes in microcirculatory vessels of the pancreas manifested in erythrostasis, thrombosis and fibrinoid wall necrosis accompanied by the increase of pancreatic enzyme activity and decrease in blood, lymph and serum antienzyme activity developed. The treatment of experimental pancreatonecrosis with endolymphatic injection of contrical resulted in the morphologically confirmed attenuation of the necrosis intensity, limitation of necrotic zone size, blood circulation recovery in microcirculatory system, marked decrease of proteolytic enzyme activity and increase of blood serum and central lymph antienzyme activity.     

枯草芽胞杆菌活菌制剂促进烧伤创面愈合的实验研究

目的　探讨枯草芽胞杆菌活菌制剂对烧伤创面愈合的影响。方法　通过大鼠深Ⅱ°烧伤模型,使用枯草芽胞杆菌活菌制剂,观察烧伤创面愈合过程中,成纤维细胞增殖周期的变化,以及测定羟脯氨酸（OHP）的含量,同时记录烧伤创面愈合时间,从而评价该制剂对烧伤创面愈合的影响。结果　应用枯草芽胞杆菌活菌制剂可促进成纤维细胞分裂、增殖,胶原含量提高,创面愈合时间明显缩短。结论　枯草芽胞杆菌活菌制剂具有促进烧伤创面愈合的作用。     

Effect of topical phenytoin on burn wound healing in rats

To evaluate the effect of phenytoin on burn wounds and to compare the effect of the combination of topical phenytoin preparation in dexamethasone treated burn wounds in rats, partial thickness thermal burn wounds were inflicted upon five groups of six rats each. Group I was assigned as control, Group II received the standard silver sulphadiazine, Group III was given topical phenytoin and Group IV received injection dexamethasone, Group V received the combination of the phenytoin and the dexamethasone. The parameters observed were epithelialization period, percentage of wound contraction and histopathological analysis as indicative of the process of healing. Phenytoin group showed significant improvement in burn wound contraction in comparison to standard silver sulphadiazine group, the combination group of topical phenytoin and dexamethasone also showed significant contraction compared to dexamethasone group. The period of epithelialization also decreased significantly in groups II, III and V. In conclusion, phenytoin promotes burn wound healing as evidenced by decrease in period of epithelialization and faster wound contraction.     

Complex evaluation of wound healing process by a deep wound rat model with implanted polychlorvinyl camera

A simultaneous study of wound proteolytic activity and morphological picture of the first stages of wound healing on rat deep wound model has been shown. The process of wound healing can be evaluated by dynamics of matrix metalloproteinase activities in wound fluid. Changes in activities of different matrix metalloproteinases correlate with different stages of healing. Implantation of polychlorvinyl camera in the wound makes it possible to obtain the volume of wound fluid sufficient for a complex evaluation of healing at the initial stages of wound process.     

Matrix metalloproteinases MMP-2 and MMP-9 of wound and burn exudates and their effect on extracellular matrix proteins

The dynamics of matrix metalloproteinases (MMP), as well as of fibronectin concentration in wound and burn fluids was traced. The wound fluid proteolytic activity was studied by gelatin zymography method. The data on degradation of fibronectin and various laminin isoforms by wound fluid proteases show that laminin-1, laminin-2/4 and fibronectin were degraded by wound fluid into small fragments. Remodelling of extracellular matrix proteins occurs. Dynamics of MMP-2 and MMP-9 content in wound or burn fluids as well as that of adhesive protein fibronectin content could be used as a base for development of method of controlling the extracellular matrix remodelling process.     

Liposomal form of dihydroquercetin contributes to skin regeneration after thermal burns

It was found that dihydroquercetin, a flavonoid of plant origin, localized in lecitin nanoparticles with glycine amino acid, reduced inflammatory reactions in wound zones after thermal burns. The application of the liposomal complex to burn trauma stabilized the endogenous antioxidant system and minimized the area of secondary necrosis in the wound. The intensification of skin regeneration and repair of hair follicles and sebaceous glands were also observed.     

The "air pouch" model in mice and a study of the wound fluid proteolytic activity

The experimental model of a cutaneous wound in mice has been offered, aimed to study the proteolytic activity of the wound fluid produced at early stages of wound healing, and to examine the continuous inflammatory state. The presence of metalloproteinases MMP-2 and MMP-9 in the wound fluid matrix was found to correlate with the existence of neutrophils and macrophages in the tissue.     

壳聚糖抗菌生物医用膜在烧伤创面中的临床应用

目的总结水溶性壳聚糖抗菌生物医用膜凝胶剂(商品名:凯舒林)对人体II度烧伤创面的治疗作用和安全性,并探索后期创面色素沉着、瘢痕增殖的机制。方法选择II度烧伤患者60例,用药前均用生理盐水清洁创面、去腐皮,于创面上均匀涂壳聚糖抗菌生物医用膜治疗,观察记录创面成痂、止痛、感染及痂下愈合时间,追踪随访6个月后创面色素沉着及瘢痕增殖程度。结果本组60例使用壳聚糖抗菌生物医用膜治疗的烧伤患者,创面全部自行愈合。治愈时间:浅Ⅱ度患者平均8.5 d;深Ⅱ度患者平均19 d。创面愈合后随访6个月,浅Ⅱ度创面患者3个月内有轻度色素改变,3个月后逐步恢复正常;深Ⅱ度创面患者3个月后部分患者有散在的点样色素脱失改变;部分患者有散在的扁平瘢痕。随访6个月,创面色素沉着和瘢痕增生程度明显减轻,功能明显改善,未见瘢痕疙瘩增殖。结论壳聚糖抗菌生物医用膜用于烧伤创面具有良好的组织相容性,止痛效果好,创面成痂快,兼有控制创面感染,促进愈合,减轻瘢痕增殖的作用,无明显不良反应,安全性好。     

丹参酮IIA磺酸钠对烧伤植皮创面愈合及瘢痕形成的影响

目的:探讨丹参酮IIA磺酸钠注射液对烧伤患者植皮创面愈合及瘢痕形成情况的影响。方法:选取2014年3月至2014年12月我院收治的烧伤植皮患者62例,根据临床用药分为试验组(使用丹参酮IIA磺酸钠注射组)与对照组(未使用丹参酮IIA磺酸钠注射液)。比较两组创面愈合情况,术后植皮成活率及愈合后瘢痕形成情况。结果:1经治疗,两组创面均愈合,试验组患者植皮成活率为(97.12±1.89)%,高于对照组(89.96±1.86)%,差异具有统计学意义(P0.01);试验组愈合时间较对照组短,试验组创面愈合时间为10.1±1.9天,对照组为14.3±2.3天,两组比较差异具有统计学意义(P0.001);瘢痕形成评价试验组均优于对照组,差异具有统计学意义,其中血肿面积(1.50±0.03 vs.3.04±0.08,P0.01)、畸形率[2(6.45)vs.8(25.81),P0.05]、感染率[2(6.45)vs.9(29.03),P0.05]。结论:丹参酮IIA磺酸钠注射液对于烧伤植皮创面的患者,能够提高植皮成活率,促进创面愈合,减轻瘢痕形成,改善创面愈合质量。     

磺胺嘧啶银混悬液联合银锌霜分阶段疗法在大面积烧伤中的应用

目的：观察2008年1月至2010年12月期间98例TBSA大于35%的烧伤病人创面联合应用磺胺嘧啶银混悬液联合银锌霜的疗效。方法：以同期76例应用碘伏的病人作为对照,两组病人的平均年龄、烧伤面积、Ⅲ度面积无显著差别,用药方式均以半暴露为主。结果：磺胺嘧啶银混悬液联合银锌霜组能显著增加细菌转阴率,减少抗生素应用时间及植皮手术次数,缩短愈合时间。结论：磺胺嘧啶银混悬液联合银锌霜较碘伏能显著增加抗感染能力,有利于肉芽创面形成,为自行愈合或再次手术打下良好基础,值得应用。     

The effect of the treatment of skin wounds in rats with hydrolytic enzymes on the synthetic activity of the epidermocytes]

Epidermis cells synthetic activity was studied by a luminescent microscopy method. Different conditions of skin wound healing in intrascapular region were investigated on 84 rats-males. Daily effect of 0.2% trypsin or 0.1% ronidase solution on the healing surface for 20 min has been shown to increase basal layer cells synthetic activity of forming epidermis in comparison with control. However, maximum raise of epidermis cells functional activity after ronidase influence was observed already on the 4th day, while after trypsin action--only on the 7th. Epithelial cells synthetic activity decreases several days before total skin defect epithelialization. In all experiments their activity stabilizes not less than one month after the operation. We have come to a conclusion that the mechanism of healing acceleration due to proteolytic enzymes depends on basal layer cells synthetic activity of forming epithelium.     

Effect of burn exudate on functional activity of Balb/3T3 cell line and the role of matrix metalloproteinases in this process

The influence of burn fluid and its matrix metalloproteinases (MMPs) on Balb/3T3 cells was studied. The influence of burn fluid was assessed by morphology and specific functional activities of cells characteristic of the healing process--proliferation, monolayer contraction and migration of cells in wound model. The presence of burn fluid in cultivating medium accelerated cell proliferation by 2.5 times compared to normal conditions, promoted fibroblast monolayer contraction, and accelerated cell migration on the wound surface, thus stimulating cell functions necessary for successful heating. This effect is partly due to MMPs. The burn fluid contains, presumably, some additional factors not inhibited by specific MMP inhibitors EDTA and 1,10-phenantrolin. These factors may stimulate migration and proliferation of cells. The presence of 1-2% burn fluid is sufficient for enhancing cell proliferation.     

Thymosin beta 4 improves dermal burn wound healing via downregulation of receptor of advanced glycation end products in db/db mice

BackgroundThe delay of dermal burn wound healing caused by vascular disorders is a critical problem for many diabetic patients. Thymosin β₄ (Tβ₄), identified by subtractive cloning of endothelial cells on plastic versus basement membrane substrates, has been found to promote angiogenesis and dermal wound repair in rats, aged mice, and db/db diabetic mice. However, previous studies involving the role of Tβ₄ in wound repair were limited to mechanical damage and dermal impairment. Thus, this study aimed to evaluate the improvement of healing of burn wounds by Tβ₄ in relation to advanced glycation end products (AGE), which are pathological factors in diabetes.MethodsWe adapted a dermal burn wound in vivo model in which the dorsal skin of db/db mice was exposed for 10 s to 100 °C heated water to produce a deep second-degree burn 10 mm in diameter. Five mg/kg of Tβ₄ was then injected intradermally near the burn wound twice a week for 2 weeks.ResultsAfter treatment, Tβ₄ improved wound healing markers such as wound closure, granulation, and vascularization. Interestingly, Tβ₄ reduced levels of receptor of AGE (RAGE) during the wound healing period.ConclusionsTβ₄ exerts effects to remedy burn wounds via downregulation of RAGE.General significanceOur results suggest the potential importance of Tβ₄ as a new therapy for impaired burn wound healing that is associated with diabetes.     

Comparative evaluation of aloe vera in the management of burn wounds in guinea pigs

An experimental study was designed using Hartley guinea pigs, who received full-thickness burns covering 3 percent of their body surface area by direct contact with a hot plate. A total of 40 animals were equally divided among four modalities of closed burn wound management as follows: group I: silver sulfadiazine (Silvadine); group II: aloe vera gel extract (Carrington Dermal Wound Gel); group III: salicylic acid cream (aspirin); and group IV: plain gauze occlusive dressing only. The dressings were changed daily, and the size and appearance of each burn wound were recorded until complete healing. On the sixth postburn day, quantitative burn wound cultures were made. The average time to complete healing in the control group was 50 days, and the only significant difference was found in the aloe vera-treated animals, which healed on an average of 30 days (p less than 0.02). Wound bacterial counts were effectively decreased by silver sulfadiazine (p = 0.015) and by aloe vera extract (p = 0.015). From our data it appears that aloe gel extracts permit a faster healing of burn wounds.     

Gene expression analysis in burn wounds of rats

The events occurring early in the burn wound trigger a sequence of local and systemic responses that influence cell and tissue survival and, consequently, wound healing and recovery. Using high-density oligonucleotide arrays we identified gene expression patterns in skin samples taken from a region of injury in the burn rat model. The associated genomic events include the differential expression of genes involved in cell survival and death, cell growth regulation, cell metabolism, inflammation, and immune response. The functional gene cluster detected and their time appearance matched the time sequence known to occur in burn wound healing.     

Wound degradomics - current status and future perspectives

Proteases are pivotal modulators of extracellular matrix components and bioactive proteins at all phases of cutaneous wound healing and thereby essentially contribute to the successful reestablishment of skin integrity upon injury. As a consequence, disturbance of proteolytic activity at the wound site is a major factor in the pathology of chronic wounds. A large body of data acquired in many years of research provide a good understanding of how individual proteases may influence the repair process. The next challenge will be to integrate these findings and to elucidate the complex interactions of proteolytic enzymes, their inhibitors and substrates on a system-wide level. Here, we present novel approaches that might help to achieve this ambitious goal in cutaneous wound healing research.