Comb Burn Research Articles

Global research patterns and advances in comb burn treatment: a comprehensive bibliometric analysis

Aims: This study conducts a bibliometric analysis of literature on stasis zones and comb burns, essential for understanding and treating burn injuries. The comb burn model, introduced by Regas, has facilitated animal studies on burn pathophysiology. The Jackson burn model categorizes burns into three zones: coagulation, stasis, and hyperemia, with the stasis zone posing significant treatment challenges. Utilizing animal models, especially rats, is common in burn research. Methods: The comb burn model uses a heated brass comb to study the stasis zone effectively. A PubMed search identified 68 relevant articles, analyzed using Biblioshiny within R Studio. Results: Results indicated that "Burns: Journal of the International Society for Burn Injuries" and "Journal of Burn Care & Research" are key journals. Significant contributors include authors like Singer AJ and McClain SA. The United States, China, and Turkey are leading countries in this research area. The study emphasizes the need for standardized methodologies and improved animal models. Conclusion: The analysis highlights the necessity for ongoing research and international collaboration to advance comb burn understanding and treatment.

Non-analgesic effects of opioids: Topical application of Eucerin-based ointment containing opium on the healing process of thermal skin damage in rats.

The present study aimed to investigate the efficacy of different doses of Eucerin-based ointment containing opium compared to routine treatment on experimentally induced burn injury. Male Wistar rats were divided into five experimental groups for topical application: silver sulfadiazine 1% (SSD), Eucerin-based ointment containing opium at concentrations of 0.05%, 0.5%, and 5%, and a Eucerin-based ointment containing 0.05% opium plus SSD (mixed group), following burn wound induction using the comb burn model. An equal volume of different ointments was administered topically. The wound appearances of different groups were photographed at different time points for 21 days. In addition, blood and skin samples were taken 2 and 10 days after thermal injury to assess inflammatory parameters and oxidative stress markers. Also, the liver enzyme activity and kidney function tests were assessed on day 10. The body weight in Opium 5% significantly decreased compared to all other groups after ten days. The wound area was significantly reduced (P<0.05) in three groups: Opium 0.05%, Opium 0.5%, and mixed, compared to the SSD group on days 14 and 21. On day 21, the wound size in the Opium 5% group was significantly larger than that in the SSD group. Significantly lower serum levels of MDA were observed in all groups compared to the SSD group on days 2 and 10. There were no significant differences between treatment groups for concentrations of TNF-α in serum and burned skin samples (p>0.05). The serum concentrations of interleukin-10 in the mixed group were significantly higher compared to the SSD group on day 10. After ten days, groups were not different regarding AST, ALT, and creatinine concentrations (p>0.05). Histopathological analysis revealed that the wound healing efficacy of opium at its lowest concentration (0.05%) surpassed that of silver sulfadiazine (SSD). Furthermore, the combination of 0.05% opium with SSD enhanced the wound repair potential of SSD in burn injuries. This study showed that opium ointment delayed wound closure dose-dependently. Low doses of topical opium ointment and its mixed application with silver sulfadiazine had a protective role in thermal-induced injury.

Perfusion Analysis Using High-Definition Indocyanine Green Angiography in Burn Comb Model.

Indocyanine green angiography (ICGA) has been widely employed for quantitative evaluation of the rat comb burn model, but the imaging equipment, imaging protocol, and fluorescence data interpretation of ICGA remain unsatisfactory. This study aims to provide better solutions for the application of ICGA in perfusion analysis. The rat comb burn model was established under a series of different comb contact durations, including 10, 20, 25, 30, 35, and 40 s. Indocyanine green angiography was used to analyze wound perfusion. In total, 16 rats were divided into ibuprofen and control groups for the burn model, and their perfusion was compared. A total of 16 identical models were divided into standard- and high-dose indocyanine green (ICG) groups, and ICGA was conducted to investigate the dynamic change in wound fluorescence. Escharectomy was performed under real-time fluorescence mapping and navigation. The results showed that a comb contact duration of 30 s was optimum for the burn model. Indocyanine green angiography could accurately evaluate the histologically determined depth of thermal injury and wound perfusion in the rat comb model. Digital subtraction of residual fluorescence was necessary for multiple comparisons of perfusion. Dynamic changes in fluorescence and necrotic tissues were observed more clearly by high-dose (0.5 mg/kg) ICG in angiography. In conclusion, perfusion analysis by ICGA can be used to assess the histologically determined depth of thermal injury and the impact of a specific treatment on wound perfusion. Indocyanine green angiography can help to identify necrotic tissue. The above findings and related imaging protocols lay the foundation for future research.

75 Tranexamic Acid Reduces Burn Wound Conversion and Lung Inflammation in a Murine Comb Burn Model

Abstract Introduction Burn wound conversion is a process where superficial partial thickness burns convert into deep partial and even full thickness burn injuries. Unfortunately, the pathophysiology of this phenomenon is poorly understood. A therapeutic intervention that may prevent secondary progression and cell death in burn-injured tissue is desirable. Recent work by our group has established that tranexamic acid (TXA) has significant anti-inflammatory properties in addition to its well-known anti-fibrinolytic effects. This study investigates tranexamic acid as a novel therapeutic treatment to mitigate burn wound conversion and reduce systemic inflammation. Methods Sprague-Dawley rats were subjected to a hot comb burn contact injury using a 150-g brass comb preheated to 100°C, to create four rectangular burns, separated by three unburned interspaces. A subset of animals underwent the comb burn injury with an adjacent 30% TBSA contact injury using solid brass rods. The interspaces represent the ischemic zones simulating the zone of stasis. The treatment group received IP injection of TXA (100mg/kg) immediately after injury and once daily until sacrifice. Sham animals underwent an identical procedure, with application of a room temperature comb. Animals were sacrificed at 6hrs and 7-day time points post-injury. Photo images were obtained of the comb burn injury. Full-thickness biopsies from the ischemic zones and lung tissue were assessed with established histological and immunohistochemical (IHC) techniques. Results At 7-days post injury, the percentage of ischemic zones with necrosis was significantly reduced in the treatment group when compared with untreated burn controls by photographic image analysis. When compared with controls, the treatment groups had significantly less progression of ischemic zones to necrosis when assessed by standard microscopy. These findings were consistent in both the comb burn only and comb burn + 30%TBSA injury models. The TXA treatment group demonstrated significantly more expression of the regeneration marker (CTHRC-1) and a trend toward increased expression of the Ki-67 proliferation marker when compared to untreated burn group. At 6 hours post-injury, TXA significantly decreased infiltration of neutrophils in the lungs for the 30%TBSA burn injury model. Furthermore, systemic levels of mitochondrial DNA, IL-1α and TNFα were significantly lower in TXA treated animals when compared to untreated burn controls. Conclusions Animals treated with tranexamic acid demonstrated reduced burn wound conversion and decreased burn-induced SIRS response. Lung inflammation was also significantly reduced by administration of TXA after injury. Applicability of Research to Practice Tranexamic acid and agents with similar mechanisms of action may provide a treatment to reduce burn wound conversion. This therapy could be easily incorporated into standard acute burn care practices.

Saving zone of stasis in burn wounds by nanoliposomal Mg-ATP.

ATP is a crucial molecule for every energy-dependent process in cells. In ischemic tissues, ATP production declines, and it finally results in cell death. One of the most common strategies in burn wound management is saving the zone of ischemia. In the current study, Mg-ATP-containing nanoliposomes were formulated and studied in vitro and in vivo. The particle size of the vesicles was between 50 and 100 nm and the mean zeta potential was -4.05 ± 0.52 mV as evaluated by dynamic light scattering and Zeta sizer instrument, respectively. The encapsulation efficiency of ATP in the nanoliposomes was found to be 9.3%. The morphology and size of nanoliposomes were further studied by transmission electron microscopy. The standard MTT assay revealed no cytotoxicity of the nanoliposomes when tested on the rat fibroblast cells. Forty rats were randomly divided into four groups (N= 10 each). Burn wounds were created by burn comb model on the back of the rats and the zone of stasis in each group was treated every 12 h for 3 days by injecting them with the Mg-ATP-nanoliposomes. Control samples included empty nanoliposomes, unencapsulated Mg-ATP and the Krebs-Henseleit buffer. Laser Doppler flowmetry results revealed that blood perfusion in the zone of ischemia in rats treated with Mg-ATP-nanoliposomes was more than in the other groups (p< 0.05). Histopathology revealed saving zone of stasis by Mg-ATP-nanoliposomes. Findings obtained in this study demonstrated that the formulated Mg-ATP-nanoliposome has the potential to save the stasis zone in burn wounds.

Effect of intermittent fasting on saving zone of stasis in burn wounds in rats

BackgroundIntermittent Fasting (IF) has proved to have various positive effects on life span, diseases, and healing of tissues in rodents. We evaluated the protective effect of fasting in maintaining the ischemic zones in burn wounds. MethodsIn this study, 20 rats were divided into two groups where the IF rats were deprived of food for three months. Burn wounds were created by burn comb model on the back of all rats. On days 3 and 21 after injury, five rats in each group were euthanized whereby samples were collected for histopathological, immunohistochemical (Bcl2, P53 and VEGF), and biochemical (MDA, TAC, HP) evaluations. ResultsHistopathological analysis revealed epithelial layer and zone of ischemia remained viable in the intermittent fasting group on day 3. On the 21st day, epithelialization, angiogenesis, inflammation, fibrocyte-fibroblast, and collagen density were different in the ischemic and necrotic zones between the control and intermittent fasting groups (p<0.05). We found no statistical differences in Bcl2, P53, VEGF, MDA, TAC, and HP on day 3 between the intermittent fasting and control groups. ConclusionsIntermittent fasting before burn wounds reduces tissue damage caused by ischemia and enhanced the viability of cells in zone of stasis. It also accelerated wound healing by increasing epithelialization and collagen production in the skin and regulating inflammatory responses. This intervention appears to be related to better collagen arrangement and angiogenesis.

The effect of Tarantula cubensis D6 on zone of stasis in a rat burn model

AimBurn injuries are one of the most devastating injuries. Saving the zone of stasis decreases burn size, morbidity, and mortality. Tarantula cubensis (TC) increases epithelization of wounds, and increases wound contraction. In this study, we investigated the effects of TC on the stasis zone. Materials and Methods36 Wistar albino female rats were divided into 3 groups. Using brass comb burn model, at days 0 and 3, physiological serum solution in group 2, TC injection in group 3and no injection in group 1 was applied. Thermal and normal images were taken on day 10 and rats were sacrificed for histopathological examination. ResultsWe found a statistically significant difference between the 1st and 3rd group, 2nd and 3rd group regarding viable wound areas (p < 0.05), temperature difference (body-stasis zone) and mean body temperature (p < 0.05). We found no statistically significant difference between groups regarding neovascularization, inflammatory density, and vital cutaneous appendages. We found a statistically significant difference in epithelial layer thickness between the1st and 3rd groups, 2nd and 3rd groups(p < 0.05). ConclusionTC increases stasis zone viability macroscopically, increases epithelial layer thickness histopathologically, thus it promotes wound healing in burn wounds. This increase in stasis zone viability was also established with thermal imaging.

A Modified Burn Comb Model With a New Dorsal Frame That Allows for Local Treatment in Partial-Thickness Burns in Rats.

Burn wound progression (BWP) leads to vertical and horizontal injury extension. The "burn comb model" is commonly used, in which a full-thickness burn with intercalated unburned interspaces is induced. We aimed to establish an injury progressing to the intermediate dermis, allowing repeated wound evaluation. Furthermore, we present a new dorsal frame that enables topical drug application. Eight burn fields and six interspaces were induced on each of 17 rats' dorsa with a 10-second burn comb application. A developed 8-panel aluminum frame was sutured onto 12 animals and combined with an Elizabethan collar. Over 14 days, macroscopic and histologic wound assessment and laser speckle contrast imaging (LSCI) were performed besides evaluation of frame durability. The 10-second group was compared with nine animals injured with a full-thickness 60-second model. Frame durability was sufficient up to day 4 with 8 of the 12 frames (67%) still mounted. The 60-second burn led to an increased extent of interspace necrosis (P = .002). The extent of necrosis increased between days 1 and 2 (P = .001), following the 10-second burn (24% ± SEM 8% to 40% ± SEM 6%) and the 60-second burn (57% ± SEM 6% to 76% ± SEM 4%). Interspace LSCI perfusion was higher than burn field perfusion. It earlier reached baseline levels in the 10-second group (on day 1: 142% ± SEM 9% vs 60% ± SEM 5%; P &lt; .001). Within day 1, the 10-second burn showed histological progression to the intermediate dermis, both in interspaces and burn fields. This burn comb model with its newly developed fixed dorsal frame allows investigation of topical agents to treat BWP in partial-thickness burns.

Effects of taurine and apocynin on the zone of stasis

BackgroundAmong the zones of coagulation, hyperemia and stasis that occur in the burned area, the most intense metabolic process and the highest sensitivity to recovery with treatment is the zone of stasis.This metabolic process is related to how well the tissues in the zone of stasis can cope with oxidative stress. If the tissues in the zone of stasis are saved, the burn area will potentially heal faster and with less scar. In this study, we examined the effects of taurine amino acids and apocynin molecules on saving the tissues in the burn zone of stasis. MethodsThe study was conducted with 48 rats. The burn zone of stasis was created according to the pattern previously described in the literature as comb burn model. In the 21-day study, biopsies were taken for histological examination on the 3rd, 7th and 21st days of the study. In addition, macroscopic photographic analysis was performed. Biopsies were taken for biochemical analysis on the 21st day. Histologically, inflammation, reepithelialization, and collagenization were evaluated, and the CD34 immunoreactivity was analysed. Biochemically, CAT, SOD, tGSH, TAS, TOS, MDA and PPC values were determined. ResultsIn the histological examination, on the 3rd, 7th and 21st days, inflammation was found to be reduced in the groups given taurine and apocynin on the 3rd day. On the 7th day, better reepithelialization and collagenization were observed in the group given taurine. Significant reepithelialization, collagenization and hair follicle development were observed in the groups given taurine and apocynin on the 21st day. In the biochemical analysis, the effects of apocynin on antioxidant enzymes were determined to be prominent. While we found no significant difference on the 3rd and 7th days in the photographic analysis, taurine and apocynin were observed to act synergistically on the 21st day and significantly reduced the burned areas. ConclusionOn the 3rd day, taurine and apocynin prevented inflammation, the effects of taurine in the zone of stasis in the early period (7th day) are more pronounced, the effect of apocynin on antioxidant enzymes is more pronounced. In the late period (21st day), taurine and apocynin were found to be more effective in saving the zone of stasis by creating a synergistic effect.

The Effect of Udenafil on Stasis Zone in an Experimental Burn Model.

Management of the burn injuries is still a problematic issue because the stasis zone may become necrotic. We hypothesized that udenafil, a potent phospodiesterase inhibitor, can be beneficial in burn treatment by enhancing the viability of the stasis zone. Fifteen Wistar rats were randomly divided into 3 groups. Comb burn injury model was conducted bilaterally on the back of rats in each subject. Group 1 received 1 mL/d of saline orally for 7 days. Group 2 received 10 mg/kg per day of udenafil for 7 days. Group 3 received 20 mg/kg per day of udenafil for 7 days. At the end of seventh day, gross morphological and histopathological samples of stasis zone survival were evaluated. Histopathological examination of groups 2 and 3 revealed that the stasis zone was mostly viable. The mean necrotic area and severity of inflammation was significantly higher in the control group compared with the treatment groups. Significant differences were determined in treatment groups compared with control group in terms of vital stasis zone area and histopathological parameters. Udenafil treatment improved tissue survival on zone of stasis in. Future experimental studies should be conducted to develop zone of stasis treatment protocols combining udenafil with potent anti-inflammatory and antioxidant drugs.

Clostridium Collagenase Impact on Zone of Stasis Stabilization and Transition to Healthy Tissue in Burns.

Clostridium collagenase has provided superior clinical results in achieving digestion of immediate and accumulating devitalized collagen tissue. Recent studies suggest that debridement via Clostridium collagenase modulates a cellular response to foster an anti-inflammatory microenvironment milieu, allowing for a more coordinated healing response. In an effort to better understand its role in burn wounds, we evaluated Clostridium collagenase’s ability to effectively minimize burn progression using the classic burn comb model in pigs. Following burn injury, wounds were treated with Clostridium collagenase or control vehicle daily and biopsied at various time points. Biopsies were evaluated for factors associated with progressing necrosis as well as inflammatory response associated with treatment. Data presented herein showed that Clostridium collagenase treatment prevented destruction of dermal collagen. Additionally, treatment with collagenase reduced necrosis (HMGB1) and apoptosis (CC3a) early in burn injuries, allowing for increased infiltration of cells and protecting tissue from conversion. Furthermore, early epidermal separation and epidermal loss with a clearly defined basement membrane was observed in the treated wounds. We also show that collagenase treatment provided an early and improved inflammatory response followed by faster resolution in neutrophils. In assessing the inflammatory response, collagenase-treated wounds exhibited significantly greater neutrophil influx at day 1, with macrophage recruitment throughout days 2 and 4. In further evaluation, macrophage polarization to MHC II and vascular network maintenance were significantly increased in collagenase-treated wounds, indicative of a pro-resolving macrophage environment. Taken together, these data validate the impact of clostridial collagenases in the pathophysiology of burn wounds and that they complement patient outcomes in the clinical scenario.

Thermal injury induces early blood vessel occlusion in a porcine model of brass comb burn

Burn wound progression is an important determinant of patient morbidity and mortality after injury. In this study, we used the brass comb contact burn to determine burn wound vertical injury progression with a focus on blood vessel occlusion and endothelial cell death. Class A 3-month-old Yorkshire pigs received a brass comb contact burn. Burn wounds were sampled at 0, 30 min, 1, 2, 4, and 24 h. Hematoxylin Phloxin Saffron staining and vimentin immunostaining were performed to determine the depth of blood vessel occlusion and endothelial cell death, respectively. The depth of blood vessel occlusion increased by 30 min (p < 0.005) and peaked by 1 to 4 h (p > 0.05). The depth of endothelial cell death risen to a plateau at 30 min (p < 0.005) to 2 h and then peaked at 24 h (p < 0.03). We observed a progression of blood vessel occlusion and vascular endothelial cell death from the middle of the dermis to the hypodermis within 2 h to 4 h after the initial injury, namely a progression from a second-degree (partial thickness) to third-degree (full thickness) burn. These data suggest that therapeutic interventions during this time window may provide a better outcome by reducing or preventing vertical progression of blood vascular occlusion or endothelial cell death.

Metal chelation attenuates oxidative stress, inflammation, and vertical burn progression in a porcine brass comb burn model

Oxidative stress and inflammation may mediate cellular damage and tissue destruction as the burn wound continues to progress after the abatement of the initial insult. Since iron and calcium ions play key roles in oxidative stress, this study tested whether topical application of a metal chelator proprietary lotion (Livionex Formulation (LF) lotion), that contains disodium EDTA as a metal chelator and methyl sulfonyl methane (MSM) as a permeability enhancer, would prevent progression or reduce burn wound severity in a porcine model.We have reported earlier that in a rat burn model, LF lotion reduces thermal injury progression. Here, we used the porcine brass comb burn model that closely mimics the human condition for contact burns and applied LF lotion every 8 h starting 15 min after the injury. We found that LF lotion reduces the depth of cell death as assessed by TUNEL staining and blood vessel blockage in the treated burn sites and interspaces. The protein expression of pro-inflammatory markers IL-6, TNF-a, and TNFα Converting Enzyme (TACE), and lipid aldehyde production (protein-HNE) was reduced with LF treatment. LF lotion reversed the burn-induced decrease in the aldehyde dehydrogenase (ALDH-1) expression in the burn sites and interspaces. These data show that a topically applied EDTA-containing lotion protects both vertical and horizontal burn progression when applied after thermal injury. Curbing burn wound conversion and halting the progression of second partial burn to third-degree full-thickness burn remains challenging when it comes to burn treatment strategies during the acute phase. Burn wound conversion can be reduced with targeted treatments to attenuate the oxidative and inflammatory response in the immediate aftermath of the injury. Our studies suggest that LF lotion could be such a targeted treatment.

134 The Effect of Adipose Derived Stromal Vascular Fraction on Stasis Zone in an Experimental Burn Model on Streptozocin – Induced Diabetic Rats

Abstract Introduction Stasis zone is the encircling area of the coagulation zone which is a critical area determining the depth and width of the necrosis in burn patients. In our study we aim to salvage the stasis zone by injecting adipose derived stromal vascular fraction (ADSVF). Methods Intraperitoneal Streptozotocin was administered for the induction of diabetes mellitus (DM) and the development of DM was confirmed by the measurement of blood glucose levels in the blood samples with blood glucometer weekly 48 hours after injection. Rats with blood glucose levels above 200 mg/dl were accepted as diabetic. The diabetic animals were followed for 4 weeks before the intervention. Thermal injury was applied on dorsum of diabetic Sprague – Dawley rats (n=20) according to the previously described ‘‘comb burn’’ model. After the burn injury (30 minutes) on Sprague - Dawley rats; rat dorsum was separated into 2 equal parts consisting of 4 burn zones (3 stasis zone) on each pair. ADSVF cells harvested from inguinal fat pads of diabetic Sprague - Dawley rats (n=5) were injected on the right side while same amount of phosphate buffered saline (PBS) injected on the left side of the same animal. One week later, average vital tissue on the statis zone was determined by macroscopy, angiography and microscopy. Vascular density, inflammatory cell density and gradient of fibrosis were determined via immunohistochemical assay. Results Macroscopic stasis zone tissue survivability percentage (32 ± 3.28 %, 57 ± 4.28 %), average number of vessels (10.28 ± 1.28, 19.43 ± 1.72), capillary count (15.67 ± 1.97, 25.35 ± 2.15) and vascular density (1.55 ± 0.38, 2.14 ± 0.45) were higher on ADSVF side. Fibrosis gradient (1.87 ± 0.51, 1.50 ± 0.43) and inflammatory cell density (1.33 ± 0.40, 1.20 ± 0.32) were higher on the PBS side. Conclusions Macroscopic and microscopic findings determined that ADSVF has a statistically significant benefit for salvaging stasis zone on acute burn injuries in DM.

Comparison of the Effects of Stem Cell, Platelet Rich Plasma and Ovarian Follicle Fluid on Burn Stasis Zone (Experimental Study)

Objective: The basic aim in the treatment of second-degree burns is to prevent progressive cell death, and so treatments are directed at the zone of stasis. In this study, We were aimed to investigate the healing effects of using Mesenchymal Stem Cells (MSCs), Ovarian follicular fluid (OFS) and Platelet-rich plasma (PRP) on burn stasis zone in an experimental burn model. Method: Forty rats were divided randomly into four groups. Burns were created in each group according to the comb burn model. The control group received no treatment; the mesenchymal stem cell [MSC] group received MSC; the platelet-rich plasma [PRP] group received PRP; and the ovarian follicular fluid [OFF] group received OFF subcutaneously on days 1, 3 and 5. On days 1 and 21, all rats were photographed and the burn sites were calculated. At the end of day 21, all rats were sacrificed, the dorsum containing the created burns were excised, and the epithelialization, collagen amount, fibroblast density, inflammatory cell density and VEGF amounts were evaluated histopathologically. Results: The groups were assessed based on the burn site healing rate and histopathological scoring. Healing was faster in the MSC group [p<0.005], PRP group [p>0.005] and OFS group [p<0.005] than in the control group. When the treatment groups were compared with each other, the best healing was observed in the MSC, PRP and OFF groups, respectively. Conclusions: MSC, PRP and OFF were found to have a positive effect on burn healing, with MSC being the most efficient method among the three, followed by PRP and OFF, respectively, which were found to provide a faster healing than the control group.

Secondary Burn Progression Mitigated by an Adenosine 2A Receptor Agonist.

Current burn therapy is largely supportive with limited therapies to curb secondary burn progression. Adenosine 2A receptor (A2AR) agonists have anti-inflammatory effects with decreased inflammatory cell infiltrate and release of proinflammatory mediators. Using a porcine comb burn model, we examined whether A2AR agonists could mitigate burn progression. Eight full-thickness comb burns (four prongs with three spaces per comb) per pig were generated with the following specifications: temperature 115°C, 3-kg force, and 30-second application time. In a randomized fashion, animals (four per group) were then treated with A2AR agonist (ATL-1223, 3 ng/kg/min, intravenous infusion over 6 hours) or vehicle control. Necrotic interspace development was the primary outcome and additional histologic assessments were conducted. Analysis of unburned interspaces (72 per group) revealed that ATL-1223 treatment decreased the rate of necrotic interspace development over the first 4 days following injury (p < .05). Treatment significantly decreased dermal neutrophil infiltration at 48 hours following burn (14.63 ± 4.30 vs 29.71 ± 10.76 neutrophils/high-power field, p = .029). Additionally, ATL-1223 treatment was associated with fewer interspaces with evidence of microvascular thrombi through postburn day 4 (18.8% vs 56.3%, p = .002). Two weeks following insult, the depth of injury at distinct burn sites (adjacent to interspaces) was significantly reduced by ATL-1223 treatment (2.91 ± 0.47 vs 3.28 ± 0.58 mm, p = .038). This work demonstrates the ability of an A2AR agonist to mitigate burn progression through dampening local inflammatory processes. Extended dosing strategies may yield additional benefit and improve cosmetic outcome in those with severe injury.

An Atmospheric Plasma Jet Induces Expression of Wound Healing Genes in Progressive Burn Wounds in a Comb Burn Rat Model: A Pilot Study.

Burn-related injuries are devastating injuries with a high mortality rate that affect people of all ages worldwide. We assessed the effectiveness of plasma jet treatment in altering the expression of genes involved in wound healing in a prospective longitudinal observational animal study. Six male Sprague-Dawley rats weighing 350 g were used, and burn wounds were made by applying a preheated brass comb (100°C) to the back of the rats, resulting in four full-thickness burn wounds separated by three interspaces. A total of 18 burn wounds were induced on three rats. One side of the burn, on each rat received plasma treatment (plasma group), while the other side did not (control group). The interspaces were subjected to the plasma jet for 2 minutes per day until 7 days post-wounding. Plasma treatment significantly decreased the expression of proinflammatory cytokines. Furthermore, an increase in the expression of anti-inflammatory cytokines was observed in the plasma group. We showed that plasma jet treatment could improve burn wound healing by altering the expression of genes involved in the development of wound healing.

Modeling Burn Progression Using Comb Burns: The Impact of Thermal Contact Duration on Model Outcomes

BackgroundBurn progression is a phenomenon that remains poorly characterized. The mechanisms of burn conversion are not completely understood, and consequently, both predictive diagnostic tools and interventions are limited. The rat comb burn model is a commonly used approach to study horizontal burn conversion. However, there is significant variability in how the model is performed. Skin contact duration, comb device heating method, comb heating duration, amount of pressure applied, the weight of the comb, and associated depth of burn are all variables that are heterogeneous in studies utilizing the model. Materials and methodsHere, contact duration was examined to determine the impact the duration of burn delivery has on the conversion of interspaces in this model. Data from multiple experiments consisting of 10, 15, 20, 30, 40, and 45 s comb burns were compiled and assessed. Burns were made using combs heated in a 100°C dry bath and then monitored for 2 d. Interspace viability was assessed by digital and laser doppler imaging and biopsy procurement. ResultsLaser Doppler Imaging and viable interspace measurements showed that as burn duration increased, the percentage of the viable interspace and interspace perfusion decreased. Additionally, a contact time of 30 s or greater was required to result in 100% interspace conversion. ConclusionsThese results demonstrate a need to better characterize and potentially standardize the rat comb burn model to reduce variation and maintain it as a valuable tool for controlled studies of the pathophysiology of burn wound progression.

Comparison of a topical surfactant and a topical antibiotic in the rat comb burn model

BackgroundBurn injury progression in the secondary zone of ischemia is common leading to delayed healing and increased scarring. We hypothesized that a topical surfactant, would reduce burn injury progression in a validated rat comb burn model compared with topical antibiotic ointment. MethodsWe created 40 comb burns on 20 rats which were randomized to daily topical application of the surfactant or a triple antibiotic ointment. The comb burns consisted of 4 full thickness burns with 3 unburned interspaces between the 4 burns. These unburned interspaces represented the zone of ischemia, and when left untreated, generally progress to full thickness necrosis within several days. Comb burns were assessed daily for the presence of gross necrosis of the interspaces. At 7 days the comb burns were excised and blindly evaluated for the presence of histological evidence of necrosis. The study had 80% power to detect a 25% difference in the percentages of necrotic interspaces on day 7. ResultsThere were no differences in the percentages of histologically necrotic interspaces at 7 days in burns treated with the surfactant or antibiotic ointment (85% [95%CI, 74 to 92] vs. 75% [95%CI, 63 to 84]; mean difference 10% [95%CI −4 to 24]). There were also no between group differences in the percentages of grossly necrotic interspaces on any of the seven days of the experiment. The surfactant remained intact and adherent while the antibiotic had been absorbed at each daily dressing change. ConclusionsA topical surfactant did not reduce injury progression in the rat comb burn model when compared with antibiotic ointment. The surfactant was more durable than the antibiotic ointment.

The effects of epidermal growth factor on early burn-wound progression in rats.

After burns, protecting tissues by medicines in the zone of stasis reduces the width and depth of injury. This study's goal was to reduce burned tissue damage in the zone of stasis using epidermal growth factor (EGF). Forty-eight Wistar rats were separated into three groups. In all groups, the burn procedure was applied following the comb burn model. In Group 1, no postburn treatment was administered. In Group 2, physiological saline solution (0.3 cc) was injected intradermally and in Group 3, EGF (0.3 cc) was injected intradermally into stasis zone tissues after the burn procedure. Surviving tissue rates were 24.0% in Group 1, 25.3% in Group 2, and 70.2% in Group 3. The average numbers of cells stained with Nrf2, HO-1, and the number of apoptotic cells were 230, 150, and 17.5 in Group 1, 230, 145, and 15.0 in Group 2, and 370, 230, and 0 in Group 3, respectively. Values in Group 3 were found to be statistically significantly different than those of Groups 1 and 2; there was no difference between Groups 1 and 2. This study shows that EGF protects zone of stasis tissue from burn damage.