Hypertrophic scarring: the greatest unmet challenge after burn injury

Mapping the 3D remodeling of the extracellular matrix in human hypertrophic scar by multi-parametric multiphoton imaging using endogenous contrast

The hypertrophic scar is an aberrant form of wound healing process, whose clinical efficacy is limited by a lack of understanding of its pathophysiology. Remodeling of collagen and elastin fibers in the extracellular matrix (ECM) is closely associated with scar progression. Herein, we perform label-free multiphoton microscopy (MPM) of both fiber components from human skin specimens and propose a multi-fiber metrics (MFM) analysis model for mapping the structural remodeling of the ECM in hypertrophic scars in a highly-sensitive, three-dimensional (3D) manner. We find that both fiber components become wavier and more disorganized in scar tissues, while content accumulation is observed from elastin fibers only. The 3D MFM analysis can effectively distinguish normal and scar tissues with better than 95% in accuracy and 0.999 in the area under the curve value of the receiver operating characteristic curve. Further, unique organizational features with orderly alignment of both fibers are observed in scar-normal adjacent regions, and an optimized combination of features from 3D MFM analysis enables successful identification of all the boundaries. This imaging and analysis system uncovers the 3D architecture of the ECM in hypertrophic scars and exhibits great translational potential for evaluating scars in vivo and identifying individualized treatment targets.

Desferrioxamine Enhances 5-Aminolaevulinic Acid- Induced Protoporphyrin IX Accumulation and Therapeutic Efficacy for Hypertrophic Scar

Hypertrophic scar is a common problem after skin burns or trauma which brings physical, psychological, and cosmetic problems to patients. Photodynamic therapy with 5-aminolevulinic acid (5-ALA) is a promising therapy for hypertrophic scar. However, clinical applications of 5-ALA are limited because of the low permeability of 5-ALA in the skin stratum corneum and the rapid binding of protoporphyrin IX (PpIX) with iron ions, which lead to insufficient PpIX production in target tissues. Herein, a mixture of 5-ALA and DFO (deferoxamine, a special iron chelator) was applied for the treatment of hypertrophic scar. 5-ALA/DFO could efficiently block the biotransformation of PpIX to heme, thus realizing a significant accumulation of photosensitizer. In addition, injection locally into the lesion was applied, which combined with enhanced photodynamic therapy to destroy hypertrophic scar fibroblasts. In vitro experiments showed that 5-ALA/DFO could increase more ROS generation by increasing the accumulation of PpIX, resulting in the apoptosis of hypertrophic scar fibroblasts. Furthermore, 5-ALA/DFO inhibited the proliferation and migration of hypertrophic scar fibroblasts. In vivo study showed that 5-ALA/DFO could effectively inhibit the formation of proliferative scar. Therefore, 5-ALA/DFO has the potential to enhance the photodynamic therapy of 5-ALA and provides a new treatment strategy for hypertrophic scar.

The Complexity of the Post-Burn Immune Response: An Overview of the Associated Local and Systemic Complications

Burn injury induces a complex inflammatory response, both locally and systemically, and is not yet completely unravelled and understood. In order to enable the development of accurate treatment options, it is of paramount importance to fully understand post-burn immunology. Research in the last decades describes insights into the prolonged and excessive inflammatory response that could exist after both severe and milder burn trauma and that this response differs from that of none-burn acute trauma. Persistent activity of complement, acute phase proteins and pro- and anti-inflammatory mediators, changes in lymphocyte activity, activation of the stress response and infiltration of immune cells have all been related to post-burn local and systemic pathology. This "narrative" review explores the current state of knowledge, focusing on both the local and systemic immunology post-burn, and further questions how it is linked to the clinical outcome. Moreover, it illustrates the complexity of post-burn immunology and the existing gaps in knowledge on underlying mechanisms of burn pathology.

Clarifying sleep characteristics and analyzing risk factors of sleep disorders to promote a predictive, preventive, and personalized medicine in patients with burn scars

Purpose

This study assessed sleep quality in patients with burn scars and investigated risk factors of sleep disorders to guide clinical therapy. From the strategy of predictive, preventive, and personalized medicine (PPPM/3PM), we proposed that risk assessment based on clinical indicators could prompt primary prediction, targeted prevention, and personalized interventions to improve the management of sleep disorders present in patients with burn scars.

Methods

This retrospective study recruited patients with burn scars and healthy volunteers from the Shanghai Burn Treatment Center between 2017 and 2022. Relevant information and data, including demographic characteristics, scar evaluation, and sleep quality, were obtained through the hospital information system, classical scar scale, and self-report questionnaires. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) and monitored using a cardiopulmonary-coupled electrocardiograph. Pain and pruritus were assessed using the visual analog scale (VAS). Scar appearance was assessed using the modified Vancouver scar scale (mVSS).

Results

The sample was comprised of 128 hypertrophic scar (HS) patients, with 61.7% males, a mean age of 41.1 ± 11.6 years, and burn area of 46.2 ± 27.9% total body surface area (TBSA). Patients with PSQI ≥ 7 accounted for 76.6%, and the global PSQI score was 9.4 ± 4.1. Objective sleep data showed that initial enter deep sleep time, light sleep time, awakening time, light sleep efficiency, and sleep apnea index were higher but deep sleep time, sleep efficiency, and deep sleep efficiency were lower in HS patients than that in healthy controls. Preliminary univariate analysis showed that age, hyperplasia time of scar, narrow airway, microstomia, VAS for pain and pruritus, and mVSS total (comprised of pigmentation, vascularity, height and pliability) were associated with the PSQI score (p < 0.1). Multivariable linear regression showed narrow airway, VAS for pain and pruritus, and mVSS specifically height, were the risk factors for PSQI score (p < 0.1).

Conclusions

This study model identified that narrow airway, pain, pruritus and scar appearance specifically height may provide excellent predictors for sleep disorders in HS patients. Our results provided a basis for the predictive diagnostics, targeted prevention, and individualized therapy of somnipathy predisposition and progression of HS patients in the setting of PPPM/3PM health care system, which contributed to a paradigm shift from reactive cure to advanced therapy.

A single-stage bilayered skin reconstruction using Glyaderm® as an acellular dermal regeneration template results in improved scar quality: an intra-individual randomized controlled trial

Background

Absence of almost the entire reticular dermal layer is inherent to the use of autologous split-thickness skin grafting (STSG) to close full-thickness wounds, often resulting in hypertrophic scars and contractures. Many dermal substitutes have been developed, but unfortunately most have varying results in terms of cosmetic and/or functional improvement as well as patient satisfaction, in addition to high costs. Bilayered skin reconstruction using the human-derived glycerolized acellular dermis (Glyaderm®) has been reported to result in significantly improved scar quality using a two-step procedure. Unlike the necessary two-step procedure for most commercially available dermal substitutes, in this study we aimed to investigate the use of Glyaderm® in a more cost-effective single-stage engrafting. This is a method which, if autografts are available, is preferred by the majority of surgeons given the reduction in costs, hospitalization time and infection rate.

Methods

A prospective, randomized, controlled, intra-individual, single-blinded study was performed, investigating the simultaneous application of Glyaderm® and STSG vs. STSG alone in full-thickness burns or comparable deep skin defects. During the acute phase, bacterial load, graft take and time to wound closure were assessed and were the primary outcomes. Aesthetic and functional results (secondary outcomes) were evaluated at 3, 6, 9 and 12 months follow-up using subjective and objective scar measurement tools. Biopsies for histological analysis were taken at 3 and 12 months.

Results

A total of 66 patients representing 82 wound comparisons were included. Graft take (>95%), pain management and healing time were comparable in both groups. At 1 year follow-up, the overall Patient and Observer Scar Assessment Scale assessed by the patient was significantly in favour of sites where Glyaderm® was used. Not infrequently, patients attributed this difference to improved skin sensation. Histological analysis showed the presence of a well-formed neodermis, with donor elastin present for up to 12 months.

Conclusions

A single-stage bilayered reconstruction with Glyaderm® and STSG results in optimal graft take without loss of Glyaderm® nor the overlaying autografts due to infection. The presence of elastin in the neodermis was demonstrated during long-term follow-up in all but one patient, which is a crucial factor contributing to the significantly improved overall scar quality as evaluated by the blinded patients.

Trial registration

The trial was registered on clinicaltrials.gov and received the following registration code: NCT01033604.

Histological evaluation of the aortic wall response following endovascular aneurysm repair and endovascular aneurysm sealing

Objective

The Nellix endovascular aneurysm sealing (EVAS) system was developed as an alternative to conventional endovascular aneurysm repair (EVAR) to minimize endoleaks. A significantly higher failure rate of EVAS may be related to an interaction between the filled endobags and the AAA wall. In general, biological information on aortic remodeling after traditional EVAR is scarce. In this light, we provide here the first histologic evaluation of aneurysm wall morphology after EVAR and EVAS.

Methods

Fourteen histological human wall samples of EVAS and EVAR explantation were systematically analysed. Primary open aorta repair samples were included as reference.

Results

Compared with primary open aortic repair samples, endovascular repair aortic samples were characterized by more pronounced fibrosis, a greater number of ganglionic structures, decreased cellular inflammation, less calcification, and a lower atherosclerotic load. EVAS was specifically associated with the presence of unstructured elastin deposits.

Conclusions

The biological response of the aortic wall after endovascular repair resembles the maturation process of a scar rather than a bona fide healing response. Moreover, the inflammatory response in the aortic wall after placement of endovascular protheses is less prominent than after primary open repair. A specific post-EVAS aortic wall characteristic was unstructured elastin fragments.

Inflammatory response: The target for treating hyperpigmentation during the repair of a burn wound

Hyperpigmentation is a common complication in patients with burn injuries during wound healing; however, the mechanisms underlying its occurrence and development remain unclear. Recently, postinflammatory hyperpigmentation (PIH) was found to result from overproduction of melanin. Local or systemic inflammatory responses are often observed in patients who develop hyperpigmentation. However, we lack studies on the relationship between PIH and burn injury. Therefore, we comprehensively reviewed the existing literature on the melanogenesis of the skin, inflammatory mechanisms in pigmentation, and local or systemic alteration in inflammatory cytokines in patients suffering from burn trauma to elucidate the relationship between PIH and burn injury. We believe that this review will guide further research on regulating melanin production in the burn management process.

Interferon-α2b-Induced RARRES3 Upregulation Inhibits Hypertrophic Scar Fibroblasts' Proliferation and Migration Through Wnt/β-Catenin Pathway Suppression

Hypertrophic scar (HS) is a severe skin fibrotic disorder with unclear pathogenesis. Interferon-α2b (IFN-α2b) exerts inhibitory effects on HS in vivo and in vitro; however, the exact mechanism remains unclear. In this study, we aimed to evaluate the inhibitory effects of IFN-α2b on hypertrophic scar fibroblasts' (HSFs) proliferation and migration, and to further investigate the associated molecular mechanism. Cell Counting Kit-8 and CyQUANT assays were used to assess HSFs' proliferation; wound healing and Transwell assays were used to assess HSFs' migration; real-time quantitative polymerase chain reaction and Western blotting were used to detect messenger RNA and protein levels, respectively, of related genes; bioinformatics analysis was performed to predict the downstream target of IFN-α2b. Our findings are as follows: (1) IFN-α2b inhibited HSFs' proliferation and migration in a dose-dependent manner. (2) IFN-α2b inhibited HSFs' proliferation and migration by suppressing the Wnt/β-catenin pathway. (3) Retinoic-acid receptor responder 3 (RARRES3) was predicted as a functional downstream molecule of IFN-α2b, which was low in HSFs. (4) IFN-α2b inhibited HSF phenotypes and the Wnt/β-catenin pathway by upregulating RARRES3 expression. (5) RARRES3 restrained HSFs' proliferation and migration by repressing the Wnt/β-catenin pathway. In conclusion, IFN-α2b-induced RARRES3 upregulation inhibited HSFs' proliferation and migration through Wnt/β-catenin pathway suppression.

The Role of Local Inflammation and Hypoxia in the Formation of Hypertrophic Scars-A New Model in the Duroc Pig

Hypertrophic scars continue to be a major burden, especially after burns. Persistent inflammation during wound healing appears to be the precipitating aspect in pathologic scarring. The lack of a standardized model hinders research from fully elucidating pathophysiology and therapy, as most therapeutic approaches have sparse evidence. The goal of this project was to investigate the mechanisms of scar formation after prolonged wound inflammation and to introduce a method for generating standardized hypertrophic scars by inducing prolonged inflammation. Four wound types were created in Duroc pigs: full-thickness wounds, burn wounds, and both of them with induced hyperinflammation by resiquimod. Clinical assessment (Vancouver Scar Scale), tissue oxygenation by hyperspectral imaging, histologic assessment, and gene expression analysis were performed at various time points during the following five months. Native burn wounds as well as resiquimod-induced full-thickness and burn wounds resulted in more hypertrophic scars than full-thickness wounds. The scar scale showed significantly higher scores in burn- and resiquimod-induced wounds compared with full-thickness wounds as of day 77. These three wound types also showed relative hypoxia compared with uninduced full-thickness wounds in hyperspectral imaging and increased expression of HIF1a levels. The highest number of inflammatory cells was detected in resiquimod-induced full-thickness wounds with histologic features of hypertrophic scars in burn and resiquimod-induced wounds. Gene expression analysis revealed increased inflammation with only moderately altered fibrosis markers. We successfully created hypertrophic scars in the Duroc pig by using different wound etiologies. Inflammation caused by burns or resiquimod induction led to scars similar to human hypertrophic scars. This model may allow for the further investigation of the exact mechanisms of pathological scars, the role of hypoxia and inflammation, and the testing of therapeutic approaches.

Two-Dimensional Mg2 Si Nanosheet-Enabled Sustained Hydrogen Generation for Improved Repair and Regeneration of Deeply Burned Skin

Molecular hydrogen holds a high potential for wound healing owing to its anti-inflammatory effect and high biosafety, but commonly used hydrogen administration routes hardly achieve the sustained supply of high-dosage hydrogen, limiting hydrogen therapy efficacy. Here, two-dimensional Mg₂ Si nanosheet (MSN) is exploited as a super-persistent hydrogen-releasing nanomaterial with high biocompatibility, and the incorporation of MSN into the chitosan/hyaluronic acid hydrogel (MSN@CS/HA) is developed as a dressing to repair deeply burned skin. The MSN@CS/HA hydrogel dressing can continuously generate hydrogen molecules for about 1 week in the physiological conditions in support of local, long-term, and plentiful hydrogen supply and remarkably promotes the healing and regeneration of deep second-degree and third-degree burn wounds without visible scar and toxic side effect. Mechanistically, a sustained supply of hydrogen molecules induces anti-inflammatory M2 macrophage polarization in time by enhancing CCL2 (chemokine C-C motif ligand 2) expression to promote angiogenesis and reduce fibrosis and also enhances the proliferation and migration capability of skin cells directly and indirectly by locally scavenging overexpressed reactive oxygen species, synergistically favoring wound repair. The proposed synthesis method, therapeutic strategy, and mechanisms will open a window for synthesizing a variety of MSene nanomaterials and developing their various proangiogenesis applications besides wound healing.

Advances in 3D skin bioprinting for wound healing and disease modeling

Even with many advances in design strategies over the past three decades, an enormous gap remains between existing tissue engineering skin and natural skin. Currently available in vitro skin models still cannot replicate the three-dimensionality and heterogeneity of the dermal microenvironment sufficiently to recapitulate many of the known characteristics of skin disorder or disease in vivo. Three-dimensional (3D) bioprinting enables precise control over multiple compositions, spatial distributions and architectural complexity, therefore offering hope for filling the gap of structure and function between natural and artificial skin. Our understanding of wound healing process and skin disease would thus be boosted by the development of in vitro models that could more completely capture the heterogeneous features of skin biology. Here, we provide an overview of recent advances in 3D skin bioprinting, as well as design concepts of cells and bioinks suitable for the bioprinting process. We focus on the applications of this technology for engineering physiological or pathological skin model, focusing more specifically on the function of skin appendages and vasculature. We conclude with current challenges and the technical perspective for further development of 3D skin bioprinting.

Metformin Improves Burn Wound Healing by Modulating Microenvironmental Fibroblasts and Macrophages

Metformin, a biguanide, exerts different functions through various signaling pathways. In order to investigate the function and mechanism of metformin in burn wounds, we established burn rat models, subcutaneously injected metformin to treat the wounds, and observed the morphologies and the expression of collagen I, collagen III, fibronectin, and pro-inflammatory markers. In vitro experiments were performed to investigate the effects of metformin on the proliferation, migration, and collagen I synthesis of the mouse embryonic fibroblast (NIH 3T3) cell line and on the proliferation, apoptosis, and immune response of the mouse mononuclear macrophage (RAW 264.7) cell line. Finally, we studied the regulatory effects of metformin on a co-culture of RAW 264.7/NIH 3T3 cells. We found that 100 mM of metformin reduced dermal thickness, collagen I deposition, and mRNA expression of IL1β and CCL2 in rat burn wounds. In vitro experiments revealed that metformin inhibited the proliferation of NIH 3T3 and RAW 264.7 cells. Metformin attenuated NIH 3T3 cell migration via the AMPK/mTOR pathway and attenuated collagen I synthesis through the TGFβ1/Smad3 pathway. Metformin inhibited the apoptosis of RAW 264.7 cells induced by 10 μg/mL LPS. Metformin downregulated the mRNA expression of IL1β and CCL2 in RAW 264.7 cells under 1 μg/mL LPS induction by inhibiting NF-κB p65 phosphorylation. In a RAW 264.7/NIH 3T3 co-culture, metformin attenuated collagen I synthesis in NIH 3T3 cells by inhibiting RAW 264.7 paracrine secretion of TGF-β1. This provides new evidence related to the development of metformin for potentially improving burn wound healing.

Effectiveness of four topical treatment methods in a rat model of superficial partial-thickness burn injury: the advantages of combining zinc-hyaluronan gel with silver foam dressing

BACKGROUND

There are several options available for conservative treatment of partial-thickness burns, however, reliable, affordable, and easily obtainable animal testing models are hard to find for the comparison of the different treatment methods. We aimed at developing a preclinical testing model and at comparing four treatment methods for superficial partial-thickness burns.

METHODS

Burn injury was induced in 90 adult male Wistar rats by placing the 130°C hot tip of a commercially obtainable soldering device for 30 s on the clipped skin of the interscapular region at a steady pressure. Skin histology was studied on days 5, 10, and 22 after the induction of the burn injury, on which days, respectively, the ratio of the not epithelialized wound (%), the extent of re-epithelialization (score), and the scar thickness (µm) were assessed. We compared 4 groups: silver-sulfadiazine cream, zinc-hyaluronan gel, silver foam dressing, and the combination of zinc-hyaluronan gel with a silver foam dressing.

RESULTS

On day 5, the induction of superficial partial-thickness burn injury was confirmed histologically in the rats. The zinc-hyaluronan gel and the combination treatment resulted in a markedly smaller ratio of the non-epithelialized area (29 ± 10% and 28 ± 13%, respectively) than silver-sulfadiazine cream (69 ± 4%; p < 0.01). On day 10, the extent of re-epithelialization was the lowest (∼0.2) in the silver-sulfadiazine cream group, while the other 3 treatments performed significantly better. The combination treatment lead to the maximal score of 2 in all rats, which was higher than in the other 3 treatment groups. On day 22, the scar thickness was the smallest in the combination treatment group (560 ± 42 µm), which was significantly less than in the silver-sulfadiazine cream group (712 ± 38 µm; p < 0.05).

CONCLUSIONS

We designed and histologically confirmed a reproducible method for induction of superficial partial-thickness burns in rats for preclinical testing. In our model, the combination of zinc-hyaluronan gel with silver foam dressing was more effective than either of its components alone or than silver-sulfadiazine cream.

CO2 fractional laser-assisted transdermal delivery of silk nanofiber carriers in a rabbit ear hypertrophic scar model

BACKGROUND

Hypertrophic scars are skin fibrotic diseases, characterized by fibroblast hyperproliferation and excessive accumulation of extracellular matrix. However, topical drug application for hypertrophic scars are unsatisfactory. The purpose of this study was to explore the permeability of silk nanofiber hydrogels (SNFs) loaded with rhodamine 6G (R6G) and rhodamine 110 (R110) mediated by CO₂ fractional laser irradiation into hypertrophic scar tissues.

METHODS

In this work, R6G and R110 were chosen as hydrophilic and hydrophobic model molecules. They were loaded inside SNFs. In vivo rabbit ear hypertrophic scars were treated with CO₂ fractional laser irradiation and then R6G/R110-laden SNFs were applied to the scars to evaluate their synergetic effect on drug penetration efficiency. Their permeability was quantified by fluorescence intensity and measured by confocal laser scanning microscopy on days 1, 3, 5 and 7. More specifically, the thermal coagulation zone (CZ) and its surrounding area (peri-CZ) caused by the thermal coagulation of the laser were discussed separately.

RESULTS

Our data indicated that the SNFs promoted the penetration of R6G but not that of R110 in the peri-CZ on day 1 when combined with laser irradiation. Interestingly, both R6G and R110 were abundant in the CZ and remained stable on days 1, 3 and 5. Moreover, rapid re-epithelialization hindered the long-term permeability of both drugs.

CONCLUSION

Combining CO₂ fractional laser irradiation with SNF drug delivery could improve the efficiency of hydrophilic drug delivery within 24 h before total re-epithelialization.

Hypertrophic scar management

Scarring has major psychological and physical repercussions. Scars are often considered trivial, but they can be disfiguring and aesthetically unpleasant and may cause severe itching, tenderness, pain, sleep disturbance, anxiety, depression and disruption of daily activities. It is more efficient to prevent hypertrophic scars than treat them; early diagnosis of a problem scar can considerably impact the overall outcome. Therefore, nurses need to be as knowledgeable about scar products as they are about wound products, and their responsibility should not end once the wound has healed. Appropriate management of the scar will ensure that the wound remains healed and that the patient is happy with the outcome. The nurse is ideally placed to ensure that scars are appropriately identified and treated as early as possible.

Comparison of Long-Term Skin Quality and Scar Formation in Partial-Thickness Burn Wounds Treated with Suprathel® and epicitehydro® Wound Dressings

Background and Objectives: Scar formation after burn trauma has a significant impact on the quality of life of burn patients. Hypertrophic scars or keloids can be very distressing to patients due to potential pain, functional limitations, or hyper- or hypopigmentation. In a previous study comparing Suprathel® and the new and cheaper dressing epicitehydro®, we were able to show that pain reduction, exudation, and time until wound-healing of partial-thickness burn wounds were similar, without any documented infections. No study exists that objectively measures and compares skin and scar quality after treatment with Suprathel® and epicitehydro® at present. Materials and Methods: In this study, the scar quality of 20 patients who had been treated with Suprathel® and epicitehydro® was objectively assessed using the Cutometer®, Mexameter®, and Tewameter®, as well as subjectively with the Patient and Observer Scar Assessment Scale, 3, 6, and 12 months after burn injury. Results: In all performed measurements, no significant differences were detected in scar formation after treatment of partial-thickness burn wounds with the two dressings. Conclusions: Both the newer and less expensive wound-dressing epicitehydro® and the well-known wound-dressing Suprathel® resulted in stable wound closure and showed good cosmetic results in the follow-up examinations.

Identification of nanoparticle-mediated siRNA-ASPN as a key gene target in the treatment of keloids

Background: Keloid, also known as connective tissue hyperplasia, is a benign proliferative disorder with a global distribution. The available therapeutic interventions are steroid injections, surgical removal of keloids, radiotherapy, compression therapy, the application of cryosurgery, and many other methods.

Objectives: Existing treatments or approaches for keloids may lead to similar or even larger lesions at the site of keloid excision, leading to a high recurrence rate. Therefore, this study aims at identifying a new gene-based therapy for the treatment of keloids.

Methods: An ASPN-siRNA/nanoparticle combination (si-ASPN) and a negative siRNA/nanoparticle complex (NC) was developed on the basis of bioinformatics studies and used in vitro and in vivo experiments.

Results: The results showed a strong correlation between the development of keloids and high expression of ASPN protein. With the expression of ASPN protein greatly reduced in keloid fibroblasts and nude mice allografts after treatment with si-ASPN, the collagen and fibroblasts were also uniform, thinner, parallel and regular.

Conclusion: All the above experimental results suggest that keloid and ASPN are closely related and both fibroblast growth and metabolism of keloid are inhibited after silencing ASPN. Therefore, ASPN-siRNA delivered via nanoparticles can serve as a novel intervention therapy for the treatment of keloids.

Patient-reported Outcomes of Scar Impact: Comparing of Abdominoplasty, Breast Surgery, and Facial Surgery Patients

Scarring negatively impacts patient mental health, causing worsened self-confidence, body image, and social interactions, as well as anxiety and depression. The objective of this study is to evaluate the scarring impact after facial surgery, breast surgery, and full abdominoplasty for symptoms, appearance, psychosocial health, career, and sexual well-being using validated patient-reported outcome measures.

Macrophages play a key role in tissue repair and regeneration

Tissue regeneration after body injury has always been a complex problem to resolve for mammals. In adult mammals, the repair process after tissue injury is often accompanied by continuous and extensive fibrosis, which leads to scars. This process has been shown to severely hinder regeneration. Macrophages, as widely distributed innate immune cells, not only play an important role in various pathological processes, but also participate in the repair process before tissue regeneration and coordinate the regeneration process after repair. This review will discuss the various forms and indispensability of macrophages involved in repair and regeneration, and how macrophages play a role in the repair and regeneration of different tissues.

Electrospinning of botanicals for skin wound healing

Being the first barrier between the human body and external environments, our skin is highly vulnerable to injuries. As one of the conventional therapies, botanicals prepared in different topical formulations have been applied as medical care for centuries. With the current increase of clinical requirements, applications of botanicals are heading towards nanotechnologies, typically fused with electrospinning that forms nanofibrous membranes suitable for skin wound healing. In this review, we first introduced the main process of wound healing, and then presented botanicals integrated into electrospun matrices as either loaded drugs, or carriers, or membrane coatings. In addition, by addressing functional features of individual botanicals in the healing of injured skin, we further discussed the bioactivity of botanical electrospun membranes in relevant to the medical issues solved in the process of wound healing. As achieved by pioneer studies, due to infrequent adverse effects and the diversity in resources of natural plants, the development of electrospun products based on botanicals is gaining greater attention. However, investigations in this field have mainly focused on different methodologies used in the preparation of nanofibrous membranes containing botanicals, their translation into clinical practices remains unaddressed. Accordingly, we propose that potential clinical applications of botanical electrospun membranes require not only the further expansion and understanding of botanicals, but also an establishment of standard criteria for the evaluation of wound healing and evolutions of technologies to support the large-scale manufacturing industry.

Ablative fractional carbon dioxide laser improves quality of life in patients with extensive burn scars: A nested case-control study

BACKGROUND AND OBJECTIVES

Ablative fractional carbon dioxide laser (CO₂ -AFL) for small-area burn scar management shows encouraging outcomes. Few studies, however, focused on comprehensive outcomes following CO₂ -AFL treatment for extensive burn scars. This study evaluated whether CO₂ -AFL surgery improved the quality of life (QoL) for burn survivors with extensive hypertrophic scars.

METHODS

A retrospective nested case-control study was initiated to analyze the efficacy of CO₂ -AFL treatment for patients with large-area burn scars. Patients with extensive burn scars (≥30% total body surface area [TBSA]) were registered in our hospital from March 2016 to October 2018. Patients undergoing CO₂ -AFL surgery were divided into CO₂ -AFL group, and patients undergoing conventional surgery were matched in a 1:1 ratio as the conventional surgery group according to the burned area. The questionnaires were collected and followed up. The 36-Item Short Form Health Survey (SF-36) and Burns Specific Health Scale-Brief (BSHS-B) were the primary parameters. Secondary parameters included the Pittsburgh Sleep Quality Index (PSQI), University of North Carolina "4P" Scars Scale (UNC4P), Patient Scars Assessment Scale for Patient (POSAS-P), and Douleur Neuropathique 4 questions (DN4).

RESULTS

23 patients (55.96 ± 21.59% TBSA) were included in CO₂ -AFL group and 23 patients (57.87 ± 18.21% TBSA) in conventional surgery group. Both the BSHS-B total score (CO₂ -AFL vs. conventional surgery: 115.35 ± 29.24 vs. 85.43 ± 33.19, p = 0.002) and the SF-36 total score (CO₂ -AFL vs. conventional surgery: 427.79 ± 118.27 vs. 265.65 ± 81.66, p < 0.001) for the CO₂ -AFL group were higher than those for the conventional surgery group. Parameters for the CO₂ -AFL group were lower than those for the conventional surgery group in all of the following comparisons: PSQI total score (CO₂ -AFL vs. conventional surgery: 7.70 ± 3.74 vs. 12.26 ± 4.61, p = 0.001), POSAS-P total score (CO₂ -AFL vs. conventional surgery: 26.48 ± 6.60 vs. 33.04 ± 4.56, p < 0.001), UNC4P total score (CO₂ -AFL vs. conventional surgery: 5.57 ± 1.97 vs. 7.26 ± 1.81, p = 0.004), and DN4 score (CO₂ -AFL vs. conventional surgery: 3 [2-5] vs. 5 [4-8], p = 0.004).

CONCLUSIONS

Compared to conventional surgery, whole scar CO₂ -AFL surgery dramatically improved physical and mental health as well as QoL for people with extensive burn scars. Additionally, CO₂ -AFL enhanced the evaluation of scars including their appearance, pain, itching, and a host of other symptoms.

Acoustic Wave Therapy for the Treatment of Extensive Scar Fields: A Case Report

We report a severe scalding case with an affected skin area of 30-40% of the body surface. The patient suffered from severe itching and pain in the hypertrophic scar parts even 1.5 years after the accident. Treatment with acoustic wave therapy almost daily during the first treatment cycle was able to significantly reduce the discomfort. On representation after 1 year, the skin condition showed significant improvement. The second treatment cycle brought further improvement. At the last check-up 2 years later, the patient was free of complaints.

Skin grafting treatment of adolescent lower limb avulsion injury

Background

Under the influence of various factors, the number of lower extremity avulsion injuries in adolescents is increasing year by year. The main modality of treatment is skin grafting. There are many types of skin grafting. Although many studies on skin grafting after avulsion injuries have been published in the past few decades, there are differences in the treatment options for adolescents with post avulsion injuries.

Main body

Thorough debridement and appropriate skin grafts are essential for the surgical management of avulsion injuries for optimal prognosis. In the acquisition of grafts, progress has been made in equipment for how to obtain different depths of skin. The severity of the avulsion injury varies among patients on admission, and therefore the manner and type of skin grafting will vary. Especially in adolescents, graft survival and functional recovery are of great concern to both patients and physicians. Therefore, many efforts have been made to improve survival rate and activity.

Conclusion

This review summarizes the principles of treatment of avulsion injuries, the historical development of skin grafts, and the selection of skin grafts, hoping to be helpful for future research.

Protocol for a Global Burns Research Priority Setting Partnership to agree the most important unanswered questions in international burns care

INTRODUCTION

Burns affect 11 million people globally and can result in long-term disability with substantial associated healthcare costs. There is limited research funding to support trials to provide evidence for clinical decision-making. Research prioritisation ensures that research focuses on the topics most important to stakeholders, addressing issues of research waste and evidence gaps. The aim of this project is to agree the global top 10 research priorities important to international patients, carers and clinicians from all income status countries.

METHODS AND ANALYSIS

The Global Burns Research Priority Setting Partnership will use James Lind Alliance methods to establish the top 10 research priorities in global burns care. An initial international online multilingual survey will collect candidate research priorities from stakeholders. To increase equity in participation, the survey will also be available via the social media app WhatsApp. Additionally, interviews will be conducted. Data will be analysed to identify and collate research questions and to verify that the priorities are true clinical uncertainties. This list will then be ranked by stakeholders in order of importance via a second online survey. Finally, a consensus meeting will identify the top 10 research priorities.

ETHICS AND DISSEMINATION

The University of Bristol Medical School Faculty Ethical Committee has approved this project. Research into burn care should be prioritised to ensure that funding is focused where most needed. This should be undertaken internationally, to ensure inclusion of the views of professionals and patients from lower income countries, where the incidence of thermal burns is highest. The involvement of the James Lind Alliance will ensure that the methodology is robust and that the patient voice is heard. The final top 10 priorities will be disseminated to funders, governments and researchers internationally to inform future global burns research.

HDAC5-mediated Smad7 silencing through MEF2A is critical for fibroblast activation and hypertrophic scar formation

Transforming growth factor-β (TGF-β) signaling plays a key role in excessive fibrosis. As a class IIa family histone deacetylase (HDAC), HDAC5 shows a close relationship with TGF-β signaling and fibrosis. However, the effect and regulatory mechanism of HDAC5 in hypertrophic scar (HS) formation remain elusive. We show that HDAC5 was overexpressed in HS tissues and depletion of HDAC5 attenuated HS formation in vivo and inhibited fibroblast activation in vitro. HDAC5 knockdown (KD) significantly downregulated TGF-β1 induced Smad2/3 phosphorylation and increased Smad7 expression. Meanwhile, Smad7 KD rescued the Smad2/3 phosphorylation downregulation and scar hyperplasia inhibition mediated by HDAC5 deficiency. Luciferase reporter assays and ChIP-qPCR assays revealed that HDAC5 interacts with myocyte enhancer factor 2A (MEF2A) suppressing MEF2A binding to the Smad7 promoter region, which results in Smad7 promoter activity repression. HDAC4/5 inhibitor, LMK235, significantly alleviated hypertrophic scar formation. Our study provides clues for the development of HDAC5 targeting strategies for the therapy or prophylaxis of fibrotic diseases.

Virtual reality mobility for burn patients (VR-MOBILE): A within-subject-controlled trial protocol

In the acute phase, burn patients undergo several painful procedures. Pediatric burn care procedures conducted in hydrotherapy have been known to generate severe pain intensity and moderate to high levels of anxiety. Hydrotherapy treatments are done with the use of opioids and benzodiazepines for pain and anxiety. Unfortunately, nonpharmacological methods are rarely combined with pharmacological treatments despite evidence showing that distraction can serve as an effective method for pain management and can potentially decrease analgesic requirements in other painful medical procedures. Virtual reality (VR) is a method that uses distraction to interact within a virtual environment. The use of VR is promising for pain reduction in varying settings. Considering the lack of optimal pain and anxiety management during burn wound care and the positive effect of an immersive distraction for painful procedures, using VR for burn wound care procedures may show promising results. This is a within-subject randomized controlled trial design in which each participant will serve as his/her own control. A minimum of 20 participants, aged 7 to 17 years old undergoing a burn care session, will receive both standard and experimental treatments during the same session in a randomized order. The experimental treatment will consist of combining VR distraction using the video game Dreamland® to the current standard pharmacological care as per unit protocol. The control group will only receive the unit's standard pharmacological care. The mean difference in both pain intensity scores and in anxiety between the two different sequences will be the primary outcomes of this study. This study evaluates the effect of VR on burn wound care. If results from this study show a positive effect of VR compared to standard care, this protocol may provide guidance on how to implement this type of immersive care as part of the tools available for distraction of painful procedures for acute burn victims.

From Chronic Wounds to Scarring: The Growing Health Care Burden of Under- and Over-Healing Wounds

Significance: Wound healing is the largest medical market without an existing small molecule/drug treatment. Both "under-healing" (chronic wounds) and "over-healing" (scarring) cause a substantial biomedical burden and lifelong consequences for patients. These problems cost tens of billions of dollars per year in the United States alone, a number expected to grow as the population ages and the prevalence of common comorbidities (e.g., diabetes) rises. However, no therapies currently exist to produce the "ideal" healing outcome: efficient wound repair through regeneration of normal tissue. Recent Advances: Ongoing research continues to illuminate possible therapeutic avenues for wound healing. By identifying underlying mechanisms of wound repair-for instance, tissue mechanics' role in fibrosis or cell populations that modulate wound healing and scarring-novel molecular targets may be defined. This Advances in Wound Care Forum issue includes reviews of scientific literature and original research from the Hagey Laboratory for Pediatric Regenerative Medicine at Stanford and its alumni, including developing approaches for encouraging wound healing, minimizing fibrosis, and coaxing regeneration. Critical Issues: Wound healing problems reflect an enormous and rapidly expanding clinical burden. The issues of both under- and over-healing wound outcomes will continue to expand as their underlying causes (e.g., diabetes) grow. Targeted treatments are needed to enable wound repair with functional tissue restoration and decreased scarring. Future Directions: Basic scientists will continue to refine understanding of factors driving undesirable wound outcomes. These discoveries are beginning to be translated and, in the coming years, will hopefully form the foundation for antiscarring drugs and other wound therapeutics.

The epidemiological characteristic and trends of burns globally

Background

Burns is a type of injury, caused by unintentional exposure to substances of high temperature, including hot liquid, solid, and objects radiating heat energy, placing a high burden not only on patients’ families but also on national healthcare systems globally. It is difficult for policymakers and clinicians to formulate targeted management strategies for burns because data on current epidemiological patterns worldwide are lacking.

Methods

Data on burns were obtained from the Global Burden of Disease (GBD) 2019 Study. The incidence, disability-adjusted life years (DALYs), and deaths of burns in 204 countries and regions from 1990 to 2019 were calculated and stratified by sex, age, geographical location, and sociodemographic index (SDI). The estimated annual percentage change (EAPC) of incidence, DALYs, and deaths was calculated to evaluate the temporal trends. All analyses were performed using R software, version 4.1.1, with 2-sided P-values < .05 indicating a statistically significant difference.

Results

A total of 8,378,122 new cases (95% UI, 6,531,887–10,363,109cases) of burns were identified globally in 2019, which is almost evenly split between men and women, and most of the new cases were concentrated in the 10–19-year age group. Besides, burns account for 111,292 deaths (95% UI, 132,392–88,188) globally in 2019, most of which were concentrated in those aged 1–4 years. The burden of burns measured in DALYs was 7,460,448.65 (95% UI, 5,794,505.89–9,478,717.81) in 2019, of which 67% and 33% could be attributed to YLLs and YLDs, respectively. The EAPC of incidence, DALYs, and deaths were negative, the age-standardized rate (ASR) of incidence, DALYs, and deaths were considered to be decreasing in most of the regions, and the EAPCs were negatively correlated with SDI levels, universal health coverage (UHC), and gross domestic product (GDP).

Conclusion

Globally, the age-standardized rates of burn incidence, DALYs, and mortality, as well as the number of burn DALYs and death cases will continuously decrease, but the number of new burn cases has an increasing tendency globally. In addition, the EAPCs of burns in incidence, DALYs, and deaths indicated that the burden of burns was considered to be decreasing in most of the regions. And from the relationship of EAPCs with SDI, UHC index, and GDP, indicate that prevention burns not only depend on health spending per capita but also depend on the education level per capita and healthcare system performance, but it does not mean higher health spending corresponds to higher UHC index, which needs high efficiency of translating health spending into individuals health gains.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13887-2.

Therapeutic targeting of mechanical stretch-induced FAK/ERK signaling by fisetin in hypertrophic scars

Hypertrophic scarring is a complex fibrotic disease with few treatment options. Mechanical stress has been proven to be crucial for hypertrophic scar (HS) formation. Here, we showed that the flavonoid small molecule fisetin, could dramatically ameliorate HS formation in a mechanical stretch-induced mouse model. In addition, in vitro and in vivo studies demonstrated that fisetin inhibited the stretch-induced profibrotic effects by suppressing the proliferation, activation, and collagen production of fibroblasts. Mechanistically, we revealed that fisetin obviously downregulated mechanical stretch-induced the phosphorylation of FAK and ERK, and reduced nuclear localization of ERK. This bioactivity of fisetin may result from its selective binding to the catalytic region of FAK, which was suggested by the molecular docking study and kinase binding assay. Taken together, these findings suggest that fisetin is a promising agent for the treatment of hypertrophic scars and other excessive fibrotic diseases.

Rational Design of Intelligent and Multifunctional Dressing to Promote Acute/Chronic Wound Healing

Currently, the clinic's treatment of acute/chronic wounds is still unsatisfactory due to the lack of functional and appropriate wound dressings. Intelligent and multifunctional dressings are considered the most advanced wound treatment modalities. It is essential to design and develop wound dressings with required functions according to the wound microenvironment in the clinical treatment. This work summarizes microenvironment characteristics of various common wounds, such as acute wound, diabetic wound, burns wound, scalded wound, mucosal wound, and ulcers wound. Furthermore, the factors of transformation from acute wounds to chronic wounds were analyzed. Then we focused on summarizing how researchers fully and thoroughly combined the complex microenvironment with modern advanced technology to ensure the usability and value of the dressing, such as photothermal-sensitive dressings, microenvironment dressing (pH-sensitive dressings, ROS-sensitive dressings, and osmotic pressure dressings), hemostatic dressing, guiding tissue regeneration dressing, microneedle dressings, and 3D/4D printing dressings. Finally, the revolutionary development of wound dressings and how to transform the existing advanced functional dressings into clinical needs as soon as possible have carried out a reasonable and meaningful outlook.

5-Aminolevulinic Acid-Hyaluronic Acid Complexes Enhance Skin Retention of 5-Aminolevulinic Acid and Therapeutic Efficacy in the Treatment of Hypertrophic Scar

Hypertrophic scar is a serious skin disorder, which reduces the patient's quality of life. 5-aminolevulinic acid (5-ALA)-mediated photodynamic therapy has been used to treat patients with hypertrophic scar. However, the poor skin retention of 5-ALA limited the therapeutic effect. In this study, we constructed the 5-ALA-hyaluronic acid (HA) complex to potentially prolong the skin retention of 5-ALA for improving the therapeutic efficacy. HA is a polysaccharide with viscoelasticity and the carboxyl groups could conjugate with amino groups of 5-ALA via electrostatic interaction. The protoporphyrin IX (PpIX) assay revealed that 5-ALA-HA complexes markedly enhanced the skin retention, resulting in increased generation and accumulation of endogenous photosensitizer PpIX. Furthermore, 5-ALA-HA complexes allowed PpIX to be maintained at a high level for 12 h, much longer than the 3 h of 5-ALA alone. And then, the accumulative PpIX induced by 5-ALA-HA in human hypertrophic scar fibroblasts (HSF) was triggered by laser irradiation to produce sufficient reactive oxygen species, leading to efficient necrosis and apoptosis of HSF. In vivo therapeutic efficacy study indicated that 5-ALA-HA effectively reduced the appearance and scar thickness, and the scar elevation index with 5-ALA-HA treatment was significantly lower than other groups, suggesting that the 5-ALA-HA-treated scar became flattened and was closely matched to the unwounded tissues. Moreover, 5-ALA-HA treatment markedly downregulated the gene expression levels of α-SMA and TGF-β1, demonstrating attenuated the scar formation and growth. Therefore, the 5-ALA-HA complex enhancing skin retention and PpIX accumulation at the lesion site provide a promising therapeutic strategy for hypertrophic scar.

Evaluation of Bromelain-Based Enzymatic Debridement Combined with Laser Doppler Imaging and Healing of Burn Wounds

Background

Accurate estimation of burn depth is crucial for correct treatment decision making. Bromelain-based enzymatic debridement (ED) may improve clinical assessment of burn depth. Laser Doppler imaging (LDI) provides a valuable indicator of burn depth by analyzing microcirculation within tissue beds. This study aimed to evaluate bromelain-based enzymatic debridement combined with laser Doppler imaging and healing of 42 wounds in 19 patients with mixed second- and third-degree thermal burns.

Material/Methods

We included 42 wounds in 19 patients with mixed deep dermal and full-thickness thermal burns. All patients were treated with eschar-specific removal agent for ED. The perfusion of each wound after ED was assessed using LDI. Healing time was estimated by 2 experienced burn surgeons and marked by the observation of epithelization. The usefulness of the LDI performed after ED in predicting healing time was estimated. The findings were analyzed to determine a cut-off value for LDI that indicates if a burn will heal spontaneously.

Results

We observed that burn wounds with higher mean perfusion healed faster. The analysis showed a strong relationship between perfusion after ED and healing time (Spearman rank correlation coefficient=−0.803). A mean perfusion greater than 296.89 indicated that the wound could heal spontaneously and does not require skin grafting.

Conclusions

LDI examination of an already debrided wound allows for a reliable assessment of perfusion at an early stage of treatment. The use of a safe and effective debridement method in conjunction with a non-invasive diagnostic tool could improve burn management.

BioFiber: An advanced fibrous textured dressing to manage exudate in severe wounds

Biofiber is a new generation of highly absorbent, and textured bandage with patented fiber technology. Biofiber has a sophisticated texture that provides an optimum balance of moisture, flexibility, and conformability, and it has been developed with specific properties to treat complex injuries like burns. The dressing has been designed to be completely adaptable to human anatomy, and it can be fitted to any part of the body, adapting to all curves and jointures, as well as fitting the facial features. Prototypes of PLA-PCL-based textured bandages were developed by electrospinning, characterized, and evaluated for complex wound care. The texture is both esthetic and functional; fibers were uniformly sized (2.2 ± 0.8 and 4.5 ± 0.3 µm) and well interconnected. The texture facilitates vertical absorption of exudate up to 2.5 g/g of bandage, and the high contact angle values (120 - 100°) create an optimum balance of moisture for the healing process. The textured prototypes turned out to be extremely stable; no sign of bandage debris was found by the standard test, BS EN 13726-1.7. In addition, the round texture (3R) showed improvements in tensile strength (0.27 ± 0.019 MPa), ultimate tensile strength (0.83 ± 0.05 MPa) with higher breaking point (0.91 ± 0.05 MPa) compared to control (Mepilex Lite®). The amount of albumin (BSA) and Fibrinogen (Fb) adhered on textured fiber prototypes was calculated by BCA Assay, all prototypes demonstrated strong BSA (ranging from 81.66 ± 8.93 to 182.73 ± 2.07 μg protein/mg dressing) and enhanced Fb shielding (ranging from 108.25 ± 7.3 to 238.12 ± 17.76 μg protein/mg dressing). Their MVTR values ranged from 2313.27 ± 58.86 to 2603.33 ± 50.41 g/m²· day and vertical wicking heights were between 24.6 ± 2.5 and 29.3 ± 4.1 mm; biological tests demonstrated good compatibility of prototypes (cell vitality > 70 %), percentage of cells attachment was in-between 114 and 225 %. The extent of attachment depends on texture, differing topographical patterns presented higher attachment compared with both CTR + and 1P prototype (no texture). Cells were growth on textured fiber prototypes, and the extent of proliferation depend on incubation time.

Why is priority setting important for global burn care research?

The use of robust evidence is a key component of providing high quality care to patients. Synthesised evidence to support clinical decision-making is lacking for many aspects of clinical burn care. Identifying the most important areas of care that lack high quality evidence and requires research is necessary, as funding for primary research is limited. Priority setting research studies are a joint endeavour between patients, carers and clinicians to identify and rank topics for research in a healthcare area in order to reduce research waste. Such an exercise has yet to be undertaken in burns. The aim of this paper is to outline the importance of research prioritisation in burn care, to discuss how it facilitates the maximum benefit from limited research funding and to explain the methodologies used.

Pharmaceutical Prophylaxis of Scarring with Emphasis on Burns: A Review of Preclinical and Clinical Studies

Significance: The worldwide estimate of burns requiring medical attention each year is 11 million. Each year in the United States, ∼486,000 burn injuries receive medical attention, including 40,000 hospitalizations. Scars resulting from burns can be disfiguring and impair functions. The development of prophylactic drugs for cutaneous scarring could improve the outcomes for burns, traumatic lacerations (>6 million/year treated in U.S. emergency rooms), and surgical incisions (∼250 million/year worldwide). Antiscar pharmaceuticals have been estimated to have a market of $12 billion. Recent Advances: Many small molecules, cells, proteins/polypeptides, and nucleic acids have mitigated scarring in animal studies and clinical trials, but none have received Food and Drug Administration (FDA) approval yet. Critical Issues: The development of antiscar pharmaceuticals involves the identification of the proper dose, frequency of application, and window of administration postwounding for the indicated wound. Risks of infection and impaired healing must be considered. Scar outcome needs to be evaluated after scars have matured. Future Directions: Once treatments have demonstrated safety and efficacy in rodent and/or rabbit and porcine wound models, human testing can begin, such as on artificially created wounds on healthy subjects and on bilateral-surgical wounds, comparing treatments versus vehicle controls on intrapatient-matched wounds, before testing on separate cohorts of patients. Given the progress made in the past 20 years, FDA-approved drugs for improving scar outcomes may be expected.

THE IMPORTANCE OF BIOMECHANICS AND THE KINETIC CHAINS OF HUMAN MOVEMENT IN THE DEVELOPMENT AND TREATMENT OF BURN SCARS – A NARRATIVE REVIEW WITH ILLUSTRATIVE CASES

BACKGROUND

Burn scars are a major clinical sequelae of severe burn wound healing. To effectively establish a successful treatment plan and achieve durable results, understanding the pathophysiology of scar development is of utmost importance.

METHODS

A narrative review of the principles of the kinematic chain of movement and the hypothesised effect on burn scar development based on properties of burn scars was performed. An examination of the literature supporting these concepts is presented in conjunction with illustrative cases, with a particular focus on the effect of combination treatments that include ablative fractional resurfacing with surgical contracture releases.

DISCUSSION

Ablative fractional resurfacing combined with the surgical release of contractures are an effective treatment modality for burn scar reconstruction. This treatment approach seems particularly effective because it is one of the only approaches where the principles of functional kinematics can be addressed when tailoring a reconstructive approach to an individual burn patient. The presented cases illustrate the importance of recognising and including the principles of functional kinematic chains in any reconstructive treatment approach for burn scars. Further, epifascial contracture bands are cord like structures which can be found underneath the subcutaneous fat of scar contractures which follow the principles of functional kinematics. Contractures can be more efficiently released if these structures are divided as well.

CONCLUSION

Ablative fractional resurfacing combined with local tissue re-arrangements is a promising approach to address the underlying forces leading to hypertrophic burn scarring. To achieve an optimal outcome, it is essential to recognise and address the origin of the pathology when treating burn scars. Ablative fractional laser resurfacing allows a different scar approach as it is not limited to one surgical site and thus enables for effective treatment at the cause of the pathology.

Down-Regulating Scar Formation by Microneedles Directly via a Mechanical Communication Pathway

Excessive extracellular matrix deposition drives fibroblasts into a state of high mechanical stress, exacerbating pathological fibrosis and hypertrophic scar formation, leading to tissue dysfunction. This study reports a minimally invasive and convenient approach to obtaining scarless tissue using a silk fibroin microneedle patch (SF MNs). We found that by tuning the MN size and density only, the biocompatible MNs significantly decreased the scar elevation index in the rabbit ear hypertrophic scar model and increased ultimate tensile strength close to regular skin. To advance our understanding of this recent approach, we built a fibroblast-populated collagen lattice system and finite element model to study MN-mediated cellular behavior of fibroblasts. We found that the MNs reduced the fibroblasts generated contraction and mechanical stress, as indicated by decreased expression of the mechanical sensitive gene ANKRD1. Specifically, SF MNs attenuated the integrin-FAK signaling and consequently down-regulated the expression of TGF-β1, α-SMA, collagen I, and fibronectin. It resulted in a low-stress microenvironment that helps to reduce scar formation significantly. Microneedles' physical intervention via the mechanotherapeutic strategy is promising for scar-free wound healing.

Control of fibrosis and hypertrophic scar formation via glycolysis regulation with IR780

Background

Hypertrophic scars (HS) represent one of the most common clinical challenges due to unsatisfactory therapeutic results. HS formation is associated with the abnormal activation of fibroblasts and their excessive fibrotic behavior. Glycolysis dysregulation has been shown to participate in the incidence and progression of various fibrotic diseases and shows potential as a means of controlling HS formation. This work aimed to discuss the impact of augmented glycolysis on HS and to propose a method for controlling HS formation through glycolysis regulation.

Methods

Here, augmented glycolysis was confirmed together with enhanced fibrotic activity in both HS fibroblasts (HFs) and HS tissues, and the suppression of glycolysis also attenuated fibroblast activation. We also introduced IR780, a heptamethine cyanine dye, to regulate glycolysis for the control of HS formation.

Results

In vitro, cell studies indicated that IR780 significantly down-regulated glycolysis and suppressed the fibrotic activity of HFs. In vivo, the intralesional injection of IR780 into rabbit HS models led to the downregulation of glycolysis and the control of HS formation. Furthermore, IR780 accumulated preferentially in activated fibroblasts in both in vitro and in vivo studies, and thus specifically downregulated glycolysis and efficiently controlled fibrosis by targeting activated fibroblasts.

Conclusions

This work identified a strategy for controlling fibrosis and HS formation from the perspective of glycolysis regulation with IR780 targeting of activated fibroblasts.

Emerging Approach for the Application of Hibiscus sabdariffa Extract Ointment in the Superficial Burn Care

Wound healing comprises organized events involving tissue repair and regeneration. The discovery of toll-like receptors (TLRs) sheds recent light on the mechanisms involved in initiating inflammatory responses throughout the healing cascades. Hibiscus sabdariffa (HS) components may exhibit a wound healing action, owing to their antioxidant and anti-inflammatory activities. This study was designed to investigate the early effects of HS loaded in an ointment base on wound healing, antioxidant, antimicrobial effects, burning intensity, and histopathological features on the rat burn model in comparison to the standard treatment, Iruxol® ointment. A burn injury model was used to evaluate the wound healing potency of the preparation. Rats were treated with ointments three times on the day of the induction of the burn. Findings revealed that the strong antioxidant properties of the HS-loaded ointment augmented the skin healing potential by stimulating biomarkers required for skin regeneration. HS repressed the burning-induced inflammation by the effective reduction in the levels of tumor necrosis factor α (TNF-α) and IL-6 through TLR4 protein inhibition. Topical HS downregulates transforming growth factor-beta (TGF-β) levels. HS extract possesses a potential bactericidal activity against highly resistant clinical isolates of Pseudomonas aeruginosa. Overall, this study proclaims that HS-loaded topical preparations could be a valuable product that serves as adjuvants to accelerate burn wound healing through inactivating the TLR4 pathway.

Regulation of Key Immune-Related Genes in the Heart Following Burn Injury

Immune cascade is one of major factors leading to cardiac dysfunction after burn injury. TLRs are a class of pattern-recognition receptors (PRRs) that initiate the innate immune response by sensing conserved molecular patterns for early immune recognition of a pathogen. The Rat Toll-Like Receptor (TLR) Signaling Pathway RT² Profiler PCR Array profiles the expression of 84 genes central to TLR-mediated signal transduction and innate immunity, and is a validated tool for identifying differentially expressed genes (DEGs). We employed the PCR array to identify burn-induced cardiac TLR-signaling-related DEGs. A total of 38 up-regulated DEGs and 19 down-regulated DEGs were identified. Network analysis determined that all DEGS had 10 clusters, while up-regulated DEGs had 6 clusters and down-regulated DEGs had 5 clusters. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that DEGs were involved in TLR signaling, the RIG-I-Like receptor signaling pathway, the IL-17 signaling pathway, and the NFkB signaling pathway. Function analysis indicated that DEGs were associated with Toll-like receptor 2 binding, Lipopeptide binding, Toll-like receptor binding, and NAD(P)+ nucleosidase activity. The validation of 18 up-regulated DEGs (≥10-fold change) and 6 down-regulated DEGs (≤5-fold change) demonstrated that the PCR array is a trusted method for identifying DEGs. The analysis of validated DEG-derived protein–protein interaction networks will guide our future investigations. In summary, this study not only identified the TLR-signaling-pathway-related DEGs after burn injury, but also confirmed that the burn-induced cardiac cytokine cascade plays an important role in burn-induced heart dysfunction. The results will provide the novel therapeutic targets to protect the heart after burn injury.

Lycorine Inhibits Hypertrophic Scar Formation by Inducing ROS-Mediated Apoptosis

Background: Hypertrophic scar (HS) is a fibrotic cutaneous disease with few effective therapies. Lycorine is a drug with pro-apoptotic ability and anti-fibrosis potential. This study aimed to test whether lycorine could trigger the apoptosis of hypertrophic scar fibroblasts (HSFs) to inhibit HS formation.

Methods: The proapoptotic and anti-fibrosis effects of lycorine on the viability and apoptosis of human primary HSFs and their reactive oxygen species (ROS) production as well as a rabbit ear model of HS were determined by CCK-8, flow cytometry, Western blot, immunofluorescence, transwell migration, collagen gel contraction assays.

Results: Lycorine treatment selectively decreased the viability of HSFs, and induced their apoptosis, but not normal fibroblasts (NFs). Lycorine treatment increased the relative levels of Bax and cleaved PARP expression, cytochrome C cytoplasm translocation, but decreased Bcl-2, caspase-3 and caspase-9 expression, the mitochondrial membrane potential (MMP) in HSFs. Lycorine inhibited the migration and contraction of HSFs, and reduced the expression of collagen I, collagen III and α-SMA. Mechanistically, lycorine treatment stimulated high levels of ROS production, leading to apoptosis of HSFs while treatment with NAC, a ROS inhibitor, significantly mitigated or abrogated the pro-apoptotic and antifibrotic activity of lycorine in HSFs. Moreover, lycorine treatment mitigated the severity of HS in rabbit ears by inducing fibroblast apoptosis.

Conclusion: These results indicate that lycorine has a potent anti-fibrotic activity and is a potential drug for intervention of HS.

Therapeutic Effect of Autologous Activated Platelet-rich Plasma Therapy on Mid-dermal to Full-thickness Burns: A Case Series

Although modern medicine has made great strides in the management of burn injuries, associated complications such as pain, infection, dyspigmentation, and scarring have yet to be fully dealt with. Although skin grafting and meshing are routinely performed on burn patients, this method poses a risk for adverse effects. Activated autologous platelet-rich plasma (aaPRP), which is increasingly used in the field of plastic surgery, contains growth factors beneficial for wound regeneration. Seven cases of burns with varying severity and conditions that were treated with intralesional subcutaneous injection and intravenous aaPRP are presented and discussed herein. This case series indicates that subcutaneous and intravenous aaPRP is a safe procedure with the potential to be an alternative when skin grafting cannot be done or as an adjunct treatment to skin grafting.

The effect of Extracorporeal Shock Wave Therapy in the treatment of burn scars: A prospective, randomized, controlled trial

BACKGROUND

Current scientific evidence on the effect of Extracorporeal Shock Wave Therapy (ESWT) as adjunctive treatment for burn scars is scarce. However preliminary evidence, indicates it might prove a useful tool.

MATERIALS AND METHODS

A prospective, randomized, controlled study was conducted from February 2017 to February 2019. Patients with burn scars were divided into two groups with twenty patients per group. The control group received the standard treatment for burn scars. The ESWT group received the standard treatment and treatment of burn scars with ESWT 512 impulses of 0.15mJ/mm² in each session, twice per week for 4 weeks. We assessed the appearance of scar with the Vancouver Scar Scale (VSS), pruritus and pain with Visual Analog Scale (VAS) before the start of the treatment and at 2 weeks and 5 months after the treatment.

RESULTS

Both groups showed improvements in all variables through the study. However, these improvements were only statistically significant for the VSS at the 6th month for the control group and VSS and VAS pain and pruritus for the ESWT group. Nonetheless the results failed to show statistically significant differences between the ESWT and the control group neither at two weeks after treatment nor at 5 months after treatment.

CONCLUSION

Our study questions the relevance of ESWT as adjunctive treatment for burn scars as far as outward appearance, pain and pruritus as end-results are concern. Nonetheless, further studies are required to accurately assess the potential benefits of ESWT as an adjunctive treatment for burn scars.

Topical steroids in burn patients: A systematic review of the literature and a descriptive analysis of topical KENACOMB® use at a major tertiary burn centre

Background

Topical steroids are used widely to manage excessive inflammation and hypergranulation in burns; however, their use is controversial, and current evidence is largely anecdotal. Topical KENACOMB is a steroid preparation consisting of triamcinolone acetonide, neomycin, gramicidin, and nystatin, and it is standard of care at the Royal Brisbane and Women's Hospital burns unit. To our knowledge, there is no published literature that reports the use of KENACOMB to treat wound-associated inflammation and hypergranulation.

Objective

To synthesise current evidence surrounding the efficacy and safety of topical steroid use in treating inflammation and hypergranulation in burns patients. We also describe the use of topical KENACOMB in our burns unit.

Methods

A systematic review of PubMed, Cochrane, and EMBASE databases was performed. Articles published in English that reported the use of topical steroids for granulation tissue or inflammation in burn wounds or skin graft donor sites were included.

Results

We identified 350 articles, of which six met inclusion criteria. Four studies presented primary patient data, and two studies reported the results of surveys of burns unit professionals. A total of 54 patients were included across all studies, and no control group was reported in any study. Studies reported rapid improvements in healing, with 86.6%–100% of wounds showing complete reepithelialisation following treatment. Reported adverse outcomes included skin thinning, atrophy of granulation tissue, systemic side effects, and local wound infection.

Conclusions

This review highlights the paucity of conclusive evidence on the outcomes of topical steroids in treating inflammation and hypergranulation in burns and donor sites. While KENACOMB has shown efficacy in treating these wound types in our local experience, there is limited research available on the product. There is a clear need for quality research on the use of topical steroids in burns patients to better inform its ongoing clinical use.

Effectiveness of artesunate combined with fractional CO2 laser in a hypertrophic scar model with underlying mechanism

BACKGROUND AND OBJECTIVES

Both artesunate and fractional CO2 laser have been proved effective in the treatment of hypertrophic scars, yet little data are available for the efficacy of artesunate combined with fractional CO2 laser. In order to assess the pre-clinical significance and the underlying mechanism of this combined treatment profile, we attempted to observe the effectiveness of this therapy in rabbit models through determining the expression of BMP-7 and Fas.

MATERIALS AND METHODS

Twenty-Four New Zealand white rabbits with established hypertrophic scar samples were randomly divided into control group and three treatment groups. Artesunate (20 μl/cm2) was injected into the rat's scar of artesunate and combination groups, while fractional CO2 laser (Combo mode, deep energy:10 mJ, super energy: 50 mJ) was applied to rats in fractional CO2 laser and combination groups at week 4 after model establishment. All rabbits underwent a total of 3 sessions of treatment once every 2 weeks. Histological and immunohistochemistry study, Western blot assay, cell viability, ELISA and RT-QPCR were performed at week 10 to observe the aspects of hypertrophic scar sample changes and expression of BMP-7 and Fas in the scar tissues.

RESULTS

Compared with control group, hypertrophic scars and the collagen fibers were significantly inhibited after treatment, and higher inhibition was seen in the samples in combination group compared to that in artesunate and fractional CO2 laser groups (P < 0.01). Meanwhile, BMP-7 and Fas expressions were both notably increased in all treatment groups, and upregulation of the two proteins was dominant in combination group (P < 0.01).

CONCLUSIONS

Artesunate combined with fractional CO2 laser is effective in hypertrophic scarring in this rabbit model. Our findings can serve as a potential alternative strategy to treatment of hypertrophic scar in clinical practice.

The matricellular protein decorin delivered intradermally with coacervate improves wound resolution in the CXCR3-deficient mouse model of hypertrophic scarring

Cutaneous wound healing is an intricate orchestration of three overlapping phases of repair that encompass numerous cell types, signalling cascades, and microenvironment modifications to reach a successful resolution. Disruption of any of these steps will create an abnormal healing response resulting in either ulceration or excessive scarring. It has become evident that the extracellular matrix and its associated components are key orchestrators during this process. One of these essential matrix proteins is decorin, a small leucine-rich proteoglycan (SLRP) that acts as a regulator of collagen fibrillogenesis and a non-competitive inhibitor of multiple growth factors signalling cascades. Decorin is a necessary shut-off switch for the pro-reparative mechanism of the tissue replacement phase and limits the occurrence of hypertrophic scarring by preventing excessive repair. We investigated the use of decorin as a therapeutic by administering the matrix protein anchored in a slow-release coacervate in a hypertrophic scarring mouse model. The results show that early wound healing phase measurements exhibit little difference in performance compared to our coacervate-only baseline or HB-EGF-treated control mice. However, during the resolution phase of wound healing, the decorin-treatment significantly reduces cutaneous thickness, enhances collagen alignment, and improves overall wound scoring in the mice. Thus, mice treated with decorin display better healing outcomes and could limit the hypertrophic scarring phenotype in the coacervate only, and HB-EGF controls. These results suggest that decorin may be a promising tool and alternative therapy for patients who suffer from over-exuberant matrix deposition during wound healing.

Mechanomodulation of Burn Scarring Via Pressure Therapy

Significance: The physical and psychological sequalae of burn injuries account for 10 million disability-adjusted life years lost annually. Hypertrophic scarring (HSc) after burn injury results in reduced mobility, contracture, pain, itching, and aesthetic changes for burn survivors. Despite the prevalence of scarring and the number of scar therapies available, none are highly effective at preventing HSc after burn injury. Recent Advances: Recent studies modulating the mechanical environment surrounding incisional and excisional wounds have shown off-loading of tension to be a powerful strategy to prevent scar formation. Preclinical studies applying force perpendicular to the surface of the skin or using a combination of pressure both circumferentially and perpendicularly have shown substantial reductions in scar thickness and contraction after burn injury. Critical Issues: Though pressure therapy is highly effective in preclinical studies, outcomes in clinical studies have been variable and may be a result of differing therapy protocols and garment material fatigue. A recent adult clinical study reported a significant reduction in pressure after 1 month of use and significant reduction between 1 and 2 months of use, resulting in below therapeutic doses of pressure applied after only 1 month of use. Future Directions: To enhance efficacy of pressure garments, new low-fatigue materials must be developed for use in standard garments or garments must be redesigned to allow for adjustment to compensate for the loss of pressure with time. Additionally, measurements of applied pressure should be performed routinely during clinic visits to ensure that therapeutic doses of pressure are being delivered.