Burn Wound Healing Process Research Articles

CHARACTERISTICS OF IMMUNE RESPONSE UNDER EXPERIMENTAL MODELS OF ACID BURNS OF THE ESOPHAGUS

It is well known that the immune system is actively involved in the regeneration and healing process of burn wounds. However, unanswered questions remain about the role of humoral immunity in the mechanisms of healing and complications of burn wounds. We have developed an experimental model of the acid burns of the esophagus (ABE) corresponding esophageal burns in children 1-8 years. We studied the features of humoral immunity in rats with AВE, with the observed reduction of IgG and increase levels of medium and low circulating immune complexes (CIC) on the first day after the burn of the esophagus. On the 21st day after the burn, we observed an increase in the concentration of IgG and a slight accumulation of medium- and low-CIC. Studied indicators can be used for the differentiation of ABE.

Debridement of burn wounds using a hydrosurgery system

The healing process of burn wounds is strongly associated with the depth of wounds, and the depth of wounds is dependent to initial temperature and duration of contact with source of heat, infection, and secondary damage in the debridement process. On this basis, some experts present a concept of accurate debridement, which denotes removal of all necrotic tissue and at the same time protecting viable tissue for repair of raw wounds in order to maximally maintain patients' appearance and functions. A new technology of burn wound debridement--hydrosurgery system has been applied clinically. This paper summarizes the characteristics of hydrosurgery in the aspects of its technology, suitable wounds, bacterial load, amount of blood loss, and degree of pain produced during operation, and also the author's opinions regarding its efficacy to realize an accurate debridement for burn injury.

Bee pollen: chemical composition and therapeutic application.

Bee pollen is a valuable apitherapeutic product greatly appreciated by the natural medicine because of its potential medical and nutritional applications. It demonstrates a series of actions such as antifungal, antimicrobial, antiviral, anti-inflammatory, hepatoprotective, anticancer immunostimulating, and local analgesic. Its radical scavenging potential has also been reported. Beneficial properties of bee pollen and the validity for their therapeutic use in various pathological condition have been discussed in this study and with the currently known mechanisms, by which bee pollen modulates burn wound healing process.

Enhancement of Angiogenesis and Epithelialization Processes in Mice with Burn Wounds through ROS/RNS Signals Generated by Non‐Thermal N2/Ar Micro‐Plasma

Non‐thermal 0.5% N2/Ar micro‐plasma treatment with relatively high NO content was conducted on mice with second‐degree burn wounds. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) concentrations in the plasma‐exposed tissue lysate were measured. The wound closure kinetics, inflammatory responses, proliferation phase, blood flow, and formation of blood vessels in the mice were then assessed. The results showed that the wound contraction in the plasma‐exposed mice occurred five days earlier than that in the control group. The generated ROS/RNS signals stimulated the burn wound healing process, which were correlated with the angiogenesis and epithelialization processes. A possible in vivo mechanism for the enhancement of the processes in the plasma‐exposed mice is thereafter proposed.

Effect of green tea on the second degree burn wounds in rats.

Background:Various studies indicate that the green tea has anti-inflammatory and anti-oxidative properties. Moreover, a few studies have been carried out that demonstrate beneficial effects of green tea on burned patients.Materials and Methods:In this study, green tea, Vaseline, and silver sulfadiazine dressings were used as first-aid treatment to deep dermal contact burns in rats, compared with a control of nothing. After creating second-degree burn on the dorsum of rats, the treatments were applied for 15 min in four groups. Wound dressing changes were daily. Macroscopic study was performed on days 1, 3, 7, and 14 by using a digital camera and software processing of photos. Microscopic examination was done by pathologic evaluation of skin specimens on day 14.Results:We observed that green tea usage significantly decreased burn size in comparison to the control group (P = 0.004).Conclusion:Green tea is effective on healing process of second degree burn wounds.

Medicinal plants and their natural components as future drugs for the treatment of burn wounds: an integrative review

Burn wound healing is a complicated process including inflammation, re-epithelialization, granulation, neovascularization and wound contraction. Several biochemicals are involved in burn healing process including antioxidants, cytokines and liver and kidney damage biomarkers. Although several preparations are available for the management of burn wound, there is still a necessity of researching for efficacious medicine. The aim of the present study was to evaluate herbal preparations and their phytochemical constituents for burn wound management. For this purpose, electronic databases including Pubmed, Scirus, Scopus and Cochrane library were searched from 1966 to July 2013 for in vitro, in vivo or clinical studies which examined the effect of any herbal preparation on different types of burn wound. Only 3 human studies were found to include in this review. In contrast, there were 62 in vivo and in vitro studies that show the need for more clinical trials to prove the plant's potential to cure burn wound. Among single herbal preparations, Allium sativum, Aloe vera, Centella asiatica and Hippophae rhamnoides showed the best burn wound healing activity. Flavonoids, alkaloids, saponins and phenolic compounds were active constituents present in different herbs facilitating wound closure. Glycosides including madecassoside and asiaticoside and proteolytic enzymes were among the main active components. Phytochemicals represented positive activity at different stages of burn wound healing process by various mechanisms including antimicrobial, anti-inflammatory, antioxidant, collagen synthesis stimulation, cell proliferative and angiogenic effect. Overall, several herbal medicaments have shown marked activity in the management of wounds-especially burn wounds-and therefore can be considered as an alternative source of treatment. Furthermore, various natural compounds with verified burn-induced wound healing potential can be assumed as future natural drugs.

Biological activity of propolis-honey balm in the treatment of experimentally-evoked burn wounds.

Medicines of biogenic origin with micro-organic, regenerative and analgesic properties are becoming more and more significant in the treatment of burn wounds. These properties are found in apitherapeutics such as propolis and honey—products collected and processed by a honey bee. Their effect on the course of the healing processes is multidirectional. The aim of the study was a histopathological and biochemical analysis of the processes of scar formation in experimentally evoked burn wounds in white pigs treated with the 1% and 3% Sepropol balms containing standardized extracts of propolis and honey. The results were compared with the therapeutic effects obtained with dermazin cream (1% silver sulfadiazine). The level of collagen was determined in the wounds treated with 1% and 3% Sepropol and compared with the collagen level in healthy skin and wounds treated with dermazin. Granulation and regenerated epithelium formation times were compared, with the 3% Sepropol being by far the most effective. The 3% Sepropol also increased the collagen level to 116% with the control sub-groups scoring between 80% and 98%. The results show the healing process of burn wounds in pigs treated with the Sepropol balm starts earlier and has a faster course than the standard dermazin therapy.

Otostegia persica extraction on healing process of burn wounds

To investigate if the methanolic extract of the Otostegia persica can accelerating healing process of burn wound because of its anti-inflammatory and antioxidant effects. Forty eight male Wistar rats were randomized into three study groups of 16 rats each. Burn wounds were created on dorsal part of shaved rats using a metal rod. In group I the burn wound was left without any treatment. Group was treated with topical silver sulfadiazine pomade. In group III, ointment containing the OP extract was administered. Skin biopsies were harvested from burn area on the 3rd, 5th, 14th and 21st days after burn and examined histologically. Re-epithelialization in the control group and in group II was lower than in group III. Re-epithelialization in groups II and III was significantly different from that in the control group. On the 5th day of the experiment, we assessed lower inflammation in the burn area compared to control group. This means that the inflammation was suppressed by methanolic extract of OP. From day 5 to 14; the fibroblast proliferation peaked and was associated with increased collagen accumulation. It was obvious that angiogenesis improved more in the groups II and III, which facilitated re-epithelialisation. Methanolic extract of Otostegia persica exhibited significant healing activity when topically applied on rats. OP is an effective treatment for saving the burn site.

Enhancement of Fibroblast Proliferation, Vascularization and Collagen Synthesis in the Healing Process of Third-Degree Burn Wounds by Topical Arnebia euchroma, a Herbal Medicine

Introduction: The present study was conducted to evaluate the wound healing effect of Arnebia euchroma (AE) extract, which is traditionally used in some Indian, Chinese, and Iranian tribes, on histomorphometrical parameters involved in the healing process of third-degree burn wounds by using stereological analyses. Methods and Materials: In an experimental study, 48 female Sprague-Dawley rats, each with a standard third-degree burn wound on the posterior surface of the neck, were divided into four groups; AE10 and AE20 groups were treated with carboxymethylcellulose (CMC) gels which contained AE hydroalcoholic extract at the concentration of 10% and 20%, respectively; the untreated burned (UB) group, which received no treatment; and the gel-base treated group. Wound closure rate, fibroblast proliferation, volume density of collagen bundles, length density, and mean diameter of the vessels were measured. Results: Wound closure rate, fibroblast population, volume density of collagen bundles, and length density of vessels were significantly improved by AE10 and AE20 in comparison with the gel-base and UB groups (P value <0.05). Conclusion: Although previous investigations on the different aspects of the wound healing effects of AE and the results of this study exhibited the positive effects of topical Arnebia euchroma on third-degree burn wound, introducing AE as an alternative wound healing agent requires more investigations on its efficacy on human, safety, and possible adverse effects.[GMJ. 2012;1(2):53-59]

Formulation, characterization, in vitro, in vivo, and histopathological evaluation of transdermal drug delivery containing norfloxacin and Curcuma longa

Objective:In an attempt for better treatment of bacterial infections and burn wounds, semisolid formulations containing norfloxacin (NF) and natural wound healing agent Curcuma longa were prepared. The rationale behind employing combination of NF and Curcuma longa is to obtain synergistic wound healing effect. The prepared formulations were compared with silver sulfadiazine cream 1%, USP.Materials and Methods:Various ointments containing NF and C. longa were prepared using standard procedures. These formulations were evaluated for antimicrobial activity against various strains of aerobic and anaerobic microorganisms. The wound healing property was evaluated by histopathological examination and by measuring the wound contraction.Results:The significant antimicrobial and wound healing effects were demonstrated by formulations which are comparable with silver sulfadiazine 1% cream (P < 0.05). Various morphological changes were observed by histopathology during the study period (days 1, 4, 8, and 12) which also supported the wound healing process.Conclusion:Based on the observed antimicrobial and wound healing effects, the formulations containing combination of NF and Curcuma longa could be employed as an alternative to commercial silver sulfadiazine 1% cream. This innovative mode of formulation can be employed for making burn wound healing process more effective.

Delayed wound healing in aged skin rat models after thermal injury is associated with an increased MMP-9, K6 and CD44 expression

Age-related differences in wound healing have been documented but little is known about the wound healing mechanism after burns. Our aim was to compare histological features and immunohistochemical expression of matrix metalloproteinase-9 (MMP-9), collagen IV, K6 and CD44 in the burn wound healing process in aged and young rats.Following burns the appearance of the wound bed in aged rats had progressed but slowly, resulting in a delayed healing process compared to the young rats.At 21 days after injury, epithelial K6, MMP-9 and CD44 expression was significantly increased in aged rats with respect to young rats; moreover, in the aged rat group we observed a not fully reconstituted basement membrane. K6, MMP-9 and CD44 expression was significantly increased in wounded skin compared to unwounded skin both in young and aged rats.We hypothesise that delayed burn skin wound healing process in the aged rats may represent an age dependent response to injury where K6, MMP-9 and CD44 play a key role. It is therefore possible to suggest that these factors contribute to the delayed wound healing in aged skin and that modulation could lead to a better and faster recovery of skin damage in elderly.

Efficacy of topical application of alcoholic extract of yarrow in the healing process of experimental burn wounds in rabbit

Medicinal herbs have been used for thousands of years to heal burn wounds, skin ulcers, and sores. The yarrow plant (Achillea millefolium) is a well-known medicinal plant. The aim of this study was to evaluate the clinical and microbiological efficacy of the yarrow (alcoholic extract) on the healing of burn wounds in an animal model. Ten male New Zealand white rabbits, 4–6 months old and weighing 2,100 ± 240 g, were used. Experimental burn wounds (20 × 25 mm2) were created on the dorsal region of each animal. In the treatment group, the wounds were washed daily with normal saline followed by 5 ml of alcoholic extracted yarrow applied to each wounds. This procedure was repeated for 21 days. In the control group, the wounds were only washed with the same volume of normal saline over the same period. Clinical, histopathological, and microbiological evaluations of the burn wounds were carried out on days 0, 7, 14, and 21. Compared with the control group, wounds treated with the yarrow extract had a better quality of healing with a reduced microorganism count (p < 0.05). To conclude, topical application of alcoholic yarrow extract, as used in this study, not only improved the quality of healing of burn wounds but also reduced the microbiological burden of such wounds in rabbits.

Effect of Tephrosia purpurea (L) Pers. on Partial Thickness and Full Thickness Burn Wounds in Rats

The plant Tephrosia purpurea (Linn) Pers. (Fabaceae) has been used for a long time in folk medicine for the management of several diseases, including ulcers and other internal wounds. The objective of the present study was to screen the flavonoid-rich fraction of Tephrosia purpurea L. aerial parts for its burn wound repairing efficacy based on traditional uses. Flavonoid fraction ointment (5% w/w) was prepared with simple ointment base B.P. for topical application. The silver sulphadiazine ointment (standard) and simple ointment base B.P. (control) was used in partial thickness and full thickness burn wound models. Wound contraction and tensile strength were measured in partial thickness burn, where as full thickness model was used for the determination of protein, hydroxyproline, anti-oxidant enzymes (SOD, CAT and GSH) level in granuloma mass as well as for histopathological study. It was observed that, wound contraction and tensile strength of skin tissues were observed significantly greater (P&lt;0.001) in the case of flavonoid rich fraction when compared to the control group. In the full thickness burn model (on day 9), protein and hydroxyproline contents were found to be significantly higher (P&lt;0.001). Presence of matured collagen fibers and fibroblast cells with better angiogenesis was observed as a result of histopathological studies, which was visibly improved in case of treated groups compared to control group. In conclusion, our findings suggest that flavonoid-rich fraction may have a potential benefit in enhancing the burn wound healing process, possibly due to the free radical scavenging property of the plant.

CXC chemokines and their receptors: a case for a significant biological role in cutaneous wound healing.

Wound healing requires a complex series of reactions and interactions among cells and their mediators, resulting in an overlapping series of events including coagulation, inflammation, epithelialization, formation of granulation tissue, matrix and scar formation. Cytokines and chemokines promote inflammation, angiogenesis, facilitate the passage of leukocytes from circulation into the tissue, and contribute to the regulation of epithelialization. They integrate inflammatory events and reparative processes that are important for modulating wound healing. Thus both cytokines and chemokines are important targets for therapeutic intervention. The chemokine-mediated regulation of angiogenesis is highly sophisticated, fine tuned, and involves pro-angiogenic chemokines, including CXCL1-3, 5-8 and their receptors, CXCR1 and CXCR2. CXCL1 and CXCR2 are expressed in normal human epidermis and are further induced during the wound healing process of human burn wounds, especially during the inflammatory, epithelialization and angiogenic processes. Human skin explant studies also show CXCR2 is expressed in wounded keratinocytes and Th/1/Th2 cytokine modulation of CXCR2 expression correlates with proliferation of epidermal keratinocytes. Murine excision wound healing, chemical burn wounds and skin organ culture systems are valuable models for examining the role of inflammatory cytokines and chemokines in wound healing.

Using the Inflammatory Cell Infiltrate to Estimate the Age of Human Burn Wounds: A review and immunohistochemical study

The burn wound healing process, which is reviewed in this paper, has features that differ from the healing of incised cutaneous wounds. This study used immunohistochemical staining and cell counting to examine the inflammatory cell response in biopsy samples of burn wounds from live human subjects obtained at six hours until 23 days after injury in order to determine how the age of a burn could be estimated. Acute inflammatory cells predominated in samples taken six hours to two days after injury. However, neutrophils were often minimal in early samples or could be present late. Elevated numbers of macrophages tended to be encountered from days 2 to 20, but it was not uncommon to observe a minimal or absent macrophage response. Unexpectedly, there was no trend in the number of lymphocytes. A small study was also made of burn wound samples that had been obtained at post-mortem examination of subjects that died in a fire or up to 77 days after injury from fire. This revealed a similar trend of neutrophil and macrophage accumulation. Additionally, it appeared that an increase in the number of lymphocytes occurred late, from 35 days. If neutrophils predominate, the wound is probably less than a couple of days old. When macrophages are abundant the wound is probably a few days to weeks old. However, as expected from the review of the literature, the inflammatory cell infiltrate may be low or absent in burn wounds, which can render determination of the age of burn wounds difficult.

Topical treatment of standardised burns with herbal remedies in model rats

Experimental studies of burns require the use of different animal models. The aim of this work was to establish experimental model of thermal injuries and to evaluate the effects of topical agents on healing of the burn wounds. Forty female Wistar rats were randomly classified in 4 groups and isolated for 2 weeks before the onset of experiment. Animals were primarily anaesthetized with pentobarbital-sodium and then shaved (skin area of their back with diameters 5 cm x 5 cm). A round metal stamp with contact area of 5 cm2 and total weight of 100 g was heated up to 80 degrees C and then applied without additional pressure on the depilated skin of the back for 14 seconds. This procedure produced a standardized burn wound. Induced burn wounds were immediately drowned in the 4 degrees C- water for 3 s in order to maintain microcirculation. After the inducement of thermal injures, all rats were treated with 1% silver sulfadiazine cream, herbal topical preparations or were not treated at all. Burn wounds were treated twice a day until the healing completion. The result of treatment application was a significant reduction of burn wound diameters. Herbal topical preparations expressed positive therapeutic effects on the parameters of burn wounds. The efficiency of silver sulfadiazine cream in burn wound healing was significantly more expressed in comparison to healing process in control group of animals (p < or = 0,001). We conclude that herbal topical preparations efficiently caused the completion of burn wound healing process without scar formation.

050 Apoptosis in the healing process of experimental burn wound

050 Apoptosis in the healing process of experimental burn wound

Deep partial skin thickness burns: A reproducible animal model to study burn wound healing

A reproducible deep partial skin thickness burn model using guinea-pigs to study the healing process of this injury is described. Round aluminium templates heated to 75°C and applied for 5 s to the moistened, clipped and depilated dorsal skin produced the desired depth of injury. This model is applicable for the study of the three main components of the burn wound healing process: epithelialization, contraction and scar formation. It is recommended that the India ink injection technique be used to confirm the depth of the burn wound.

Is postburn dermal ischaemia enhanced by oxygen free radicals?

The accumulated data suggest that oxygen free radicals are actively involved in the pathophysiology of the wound healing process. Since OH and O 2 — directly correlate with the release of arachidonic acid and catalyse some of the enzymes participating in its cascade, their involvement in the enhancement of dermal ischaemia in the stasis zone is postulated. Experimental data using topically applied scavengers of superoxide have shown their beneficial effects on the burn wound healing process.

The regeneration of cholinesterase-positive structures in the process of burn wound healing in the skin of the guinea-pig

The regeneration of acetylcholinesterase-positive structures was studied during the process of third-degree burn wound healing in the skin of guinea-pigs. The procedure in this study generally followed the histochemical thiocholine technique of Karnovsky and Roots (1964) with slight modification. Acetylcholinesterase activity in the skin was found to disappear from the burn wound including its margin within 14 days post burn. True regeneration of acetylcholinesterase activity became visible after 21 days post burn. The cholinergic fibres reinnervating arterioles became visible on the twenty-first day, and thereafter gradually increased in number and staining intensity at the deep region of scar margins. The cholinergic fibres detected at the upper region of the scar centre on the twenty-first day disappeared on the twenty-eighth day. Such denervation of the cholinergic fibres may be elicited by the absence of the target organs or by a dense collagenous scar which induces degenerative changes in regenerated nerves. The denervation of cholinergic nerve fibres occurred in association with degeneration of the target organs. On the other hand, the regeneration of the cholinergic nerve fibres was not always associated with the regeneration of the target organs, but occurred later than that of the target organs.