Recombinant human granulocyte-macrophage colony-stimulating factor hydrogel promotes healing of deep partial thickness burn wounds

The Effects of Recombinant Human Granulocyte-Macrophage Colony-Stimulating Factor Gel on Third-Degree Frostbite Wounds in Northeastern China: A Randomized Controlled Trial

The aim of the study was to investigate the effects of the rhGM-CSF gel on third-degree frostbite wounds. Sixty-two patients who had suffered third-degree frostbite on their hand or foot (91 wounds in total) were selected using a convenience sampling method and randomly allocated to two groups: the rhGM-CSF group(31patients,45 frostbite wounds) received the rhGM-CSF gel when wound dressing change daily; however, the control group (31patients, 46 frostbite wounds) received aloe glue. The wound healing time, the score of inflammation about the wound and the positive bacterial culture of wound secretions were used to measure outcomes, respectively. Data were analyzed using SPSS (25.0), Student's t test or Mann-Whitney U test and chi-square test or Fisher exact test were selected, as appropriate. The healing time of the rhGM-CSF group was (12.2 ± 5.0) days, which was significantly shorter than that of the control group (15.5 ± 4.7) days (P < .0001). The rhGM-CSF group's wound inflammation scores on the 7th and 14th day of treatment were (0.96 ± 0.21) and (1.88 ± 0.29), respectively, which were better than those of the control group (1.12 ± 0.24) and (1.38 ± 0.15) (both P < .0001). The positive bacterial culture of wound secretions in the rhGM-CSF group was also better than that in the control group on the 3rd, 7th, and 14th day after treatment (P = .027, .004, .030, respectively). According to the results, using rhGM-CSF gel considerably increases the speed of frostbite wounds healing, and have an effect on protecting third-degree frostbite wounds regarding the positive effects. Trial Registration: This trial was registered in the Chinese Clinical Trial Register, ChiCTR1900021299.

[Low-dose topical recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF) therapy for chronic venous leg ulcers, 10-year follow-up]

BACKGROUND

The treatment of leg ulcers is an enormous problem worldwide. Chronic venous ulceration affects 1% of the population and often has a protracted course. Recurrence rate is high, ranging up to 69% in the first year after healing.

OBJECTIVES

To determine whether topical application of low-dose topical recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF) is safe in venous leg ulcer treatment, and whether it accelerates healing rates and reduces recurrence rates.

MATERIALS AND METHODS

Consecutive patients with chronic venous leg ulcers received topical treatment with low-dose rhu GM-CSF (10 µg/mL 0.9% sodium chloride solution; 1.0-2.3 µg rhu GM-CSF/cm²) in combination with treatment of venous insufficiency. All patients were previously treated with other topical wound remedies for several weeks (median 8 weeks) without success.

RESULTS

In 119 of 130 patients, the wounds healed completely (91.5%). No local or systemic adverse reactions were observed. The mean time to healing was 24 weeks (median 14 weeks). Median follow-up of the 119 patients with healed ulcers was 84 months. The recurrence rates were 5.2% after 1 year, 18.9% after 4 years and 32.0% after 10 years.

CONCLUSIONS

Topical low-dose rhu GM-CSF proved to be safe and highly effective. Healing rates were comparable to those reported in the ESCHAR study (Effects of Surgery and Compression on Healing And Recurrence in venous ulceration) and recurrence rates were the lowest reported in the literature. Topical therapy with rhu GM-CSF can be applied in an outpatient setting and does not require hospitalization.

Advances in Immunomodulation and Immune Engineering Approaches to Improve Healing of Extremity Wounds

Delayed healing of traumatic wounds often stems from a dysregulated immune response initiated or exacerbated by existing comorbidities, multiple tissue injury or wound contamination. Over decades, approaches towards alleviating wound inflammation have been centered on interventions capable of a collective dampening of various inflammatory factors and/or cells. However, a progressive understanding of immune physiology has rendered deeper knowledge on the dynamic interplay of secreted factors and effector cells following an acute injury. There is a wide body of literature, both in vitro and in vivo, abstracted on the immunomodulatory approaches to control inflammation. Recently, targeted modulation of the immune response via biotechnological approaches and biomaterials has gained attention as a means to restore the pro-healing phenotype and promote tissue regeneration. In order to fully realize the potential of these approaches in traumatic wounds, a critical and nuanced understanding of the relationships between immune dysregulation and healing outcomes is needed. This review provides an insight on paradigm shift towards interventional approaches to control exacerbated immune response following a traumatic injury from an agonistic to a targeted path. We address such a need by (1) providing a targeted discussion of the wound healing processes to assist in the identification of novel therapeutic targets and (2) highlighting emerging technologies and interventions that utilize an immunoengineering-based approach. In addition, we have underscored the importance of immune engineering as an emerging tool to provide precision medicine as an option to modulate acute immune response following a traumatic injury. Finally, an overview is provided on how an intervention can follow through a successful clinical application and regulatory pathway following laboratory and animal model evaluation.

The clinical effectiveness and safety of using epidermal growth factor, fibroblast growth factor and granulocyte-macrophage colony stimulating factor as therapeutics in acute skin wound healing: a systematic review and meta-analysis

Background

Promoting wound healing is crucial to restore the vital barrier function of injured skin. Growth factor products including epidermal growth factor (EGF), fibroblast growth factor (FGF) and granulocyte-macrophage colony stimulating factor (GM-CSF) have been used for decades although no systematic evaluation exists regarding their effectiveness and safety issues in treating acute skin wounds. This has resulted in a lack of guidelines and standards for proper application regimes. Therefore, this systematic review and meta-analysis was performed to critically evaluate the effectiveness and safety of these growth factors on skin acute wounds and provide guidelines for application regimes.

Methods

We searched PubMed/Medline (1980–2020), Cochrane Library (1980–2020), Cochrane CENTRAL (from establishment to 2020), ClinicalTrials.gov (from establishment to 2020), Chinese Journal Full-text Database (CNKI, 1994–2020), China Biology Medicine disc (CBM, 1978–2019), Chinese Scientific Journal Database (VIP, 1989–2020) and Wanfang Database (WFDATA, 1980–2019). Randomized controlled trials (RCTs), quasi-RCTs and controlled clinical trials treating patients with acute skin wounds from various causes and with those available growth factors were included.

Results

A total of 7573 papers were identified through database searching; 229 papers including 281 studies were kept after final screening. Administering growth factors significantly shortened the healing time of acute skin wounds, including superficial burn injuries [mean difference (MD) = −3.02; 95% confidence interval (CI):−3.31 ~ −2.74; p < 0.00001], deep burn injuries (MD = −5.63; 95% CI:−7.10 ~ −4.17; p < 0.00001), traumata and surgical wounds (MD = −4.50; 95% CI:−5.55 ~ −3.44; p < 0.00001). Growth factors increased the healing rate of acute skin wounds and decreased scar scores. The incidence of adverse reactions was lower in the growth factor treatment group than in the non-growth factor group.

Conclusions

The studied growth factors not only are effective and safe for managing acute skin wounds, but also accelerate their healing with no severe adverse reactions.

Functional Hydrogel Dressings for Treatment of Burn Wounds

The therapy of burns is a challenging clinical issue. Burns are long-term injuries, and numerous patients suffer from chronic pain. Burn treatment includes management, infection control, wound debridement and escharotomy, dressing coverage, skin transplantation, and the use of skin substitutes. The future of advanced care of burn wounds lies in the development of “active dressings”. Hydrogel dressings have been employed universally to accelerate wound healing based on their unique properties to overcome the limitations of existing treatment methods. This review briefly introduces the advantages of hydrogel dressings and discusses the development of new hydrogel dressings for wound healing along with skin regeneration. Further, the treatment strategies for burns, ranging from external to clinical, are reviewed, and the functional classifications of hydrogel dressings along with their clinical value for burns are discussed.

Enhancing wound healing dressing development through interdisciplinary collaboration

The process of wound healing includes four phases: Hemostasis, inflammation, proliferation, and remodeling. Many wound dressings and technologies have been developed to enhance the body's ability to close wounds and restore the function of damaged tissues. Several advancements in wound healing technology have resulted from innovative experiments by individual scientists or physicians working independently. The interplay between the medical and scientific research fields is vital to translating new discoveries in the lab to treatments at the bedside. Tracing the history of wound dressing development reveals that there is an opportunity for deeper collaboration between multiple disciplines to accelerate the advancement of novel wound healing technologies. In this review, we explore the different types of wound dressings and biomaterials used to treat wounds, and we investigate the role of multidisciplinary collaboration in the development of various wound management technologies to illustrate the benefit of direct collaboration between physicians and scientists.

Advancements in the Delivery of Growth Factors and Cytokines for the Treatment of Cutaneous Wound Indications

Significance: Wound healing involves the phasic production of growth factors (GFs) and cytokines to progress an acute wound to a resolved scar. Dysregulation of these proteins contributes to both wound chronicity and excessive scarring. Direct supplementation of GFs and cytokines for treatment of healing and scarring complications has, however, been disappointing. Failings likely relate to an inability to deliver recombinant proteins at physiologically relevant levels to an environment conducive to healing. Recent Advances: Inspired by the extracellular matrix, natural biomaterials have been developed that resemble human skin, and are capable of delivering bioactives. Hybrid biomaterials made using multiple polymers, fabrication methods, and proteins are proving efficacious in animal models of acute and impaired wound healing. Critical Issues: For clinical translation, these delivery systems must be tailored for specific wound indications and the correct phase of healing. GFs and cytokines must be delivered in a controlled manner that will target specific healing or scarring impairments. Preclinical assessment in clinically relevant animal models of impaired or excessive healing is critical. Future Directions: Clinical success will likely depend on the GF or cytokine selected, their compatibility with the chosen biomaterial(s), degradation rate of the fabricated system, and the degree of control over release kinetics. Further testing is essential to assess which wound indications are most suited to specific delivery systems and to prove whether they provide superior efficacy over direct protein therapies.

Functional Hydrogels as Wound Dressing to Enhance Wound Healing

Hydrogels, due to their excellent biochemical and mechnical property, have shown attractive advantages in the field of wound dressings. However, a comprehensive review of the functional hydrogel as a wound dressing is still lacking. This work first summarizes the skin wound healing process and relates evaluation parameters and then reviews the advanced functions of hydrogel dressings such as antimicrobial property, adhesion and hemostasis, anti-inflammatory and anti-oxidation, substance delivery, self-healing, stimulus response, conductivity, and the recently emerged wound monitoring feature, and the strategies adopted to achieve these functions are all classified and discussed. Furthermore, applications of hydrogel wound dressing for the treatment of different types of wounds such as incisional wound and the excisional wound are summarized. Chronic wounds are also mentioned, and the focus of attention on infected wounds, burn wounds, and diabetic wounds is discussed. Finally, the future directions of hydrogel wound dressings for wound healing are further proposed.

Tailoring Therapeutic Responses via Engineering Microenvironments with a Novel Synthetic Fluid Gel

This study reports the first fully synthetic fluid gel (SyMGels) using a simple poly(ethylene glycol) polymer. Fluid gels are an interesting class of materials: structured during gelation via shear-confinement to form microparticulate suspensions, through a bottom-up approach. Structuring in this way, when compared to first forming a gel and subsequently breaking it down, results in the formation of a particulate dispersion with particles "grown" in the shear flow. Resultantly, systems form a complex microstructure, where gelled particles concentrate remaining non-gelled polymer within the continuous phase, creating an amorphous-like interstitial phase. As such, these materials demonstrate mechanical characteristics typical of colloidal glasses, presenting solid-like behaviors at rest with defined yielding; likely through intrinsic particle-particle and particle-polymer interactions. To date, fluid gels have been fabricated using polysaccharides with relatively complex chemistries, making further modifications challenging. SyMGels are easily functionalised, using simple click-chemistry. This chemical flexibility, allows the creation of microenvironments with discrete biological decoration. Cellular control is demonstrated using MSC (mesenchymal stem cells)/chondrocytes and enables the regulation of key biomarkers such as aggrecan and SOX9. These potential therapeutic platforms demonstrate an important advancement in the biomaterial field, underpinning the mechanisms which drive their mechanical properties, and providing a versatile delivery system for advanced therapeutics.

Fractional CO2 laser therapy for cesarean scar under the guidance of multiple evaluation methods: A retrospective study

AIMS

To introduce the treatment experience of fractional CO₂ laser for cesarean scar under the guidance of multiple evaluation methods.

METHODS

Cesarean scar patients receiving fractional CO₂ laser therapy between January 2016 and January 2020 were retrospectively analyzed in this study. The demographic characteristics and treatment protocols, the Vancouver Scar Scale (VSS), the University of North Carolina "4P" Scar Scale (UNC4P), and the Antera3D score of all the enrolled patients were recorded.

RESULTS

Altogether, 79 cesarean scar patients were involved in this study, with the average age of 28.1 years, the average scar age and length of 26.5 (range, 24-30) months and 8.5 (range, 7-11) cm, respectively. Significant improvements were observed in VSS (t = 16.75, P < .05), UNC4P (t = 15.63, P < .05), and Antera3D score (color:t = 13.19, P < .05; texture: t = 13.12, P < .05; melanin: t = 3.89, P < .05; hemoglobin: t = 2.28, P < .05). No long-term complication was reported during the follow-up visits.

CONCLUSIONS

Fractional CO₂ laser therapy is an effective treatment for cesarean scar. The multiple evaluation methods, including the combined application of VSS, UNC4P, and Antera3D score, can be potentially used for guiding treatment protocols and evaluating efficacy. Meanwhile, rhGM-CSF hydrogel provides another choice for laser wound management.

What happens to an acellular scar matrix after implantation in vivo? A histological and related molecular biology study

It has been established that scar acellular matrices (AMs), which allow cell proliferation, have similar characteristics. The aim of this study was to investigate the repair effect of scar AMs on animals, thus providing a reference for clinical application. Selected mature and immature scar AMs were implanted into animals, and then a negative control group was set for comparison. The effect of scar AMs on wound healing was observed through tissue staining, RT-qPCR, and immunohistochemistry. The materials showed milder inflammation and faster extracellular matrix (ECM) deposition than the negative control group. The ECM deposition and new vessels increased over time. However, the arrangement of ECM in mature scar AM was more regular than in immature scar AM and the negative control group, and more new vessels grew in the mature scar AM group than in the immature scar AM group and negative control group over the same period. The transforming growth factor-β level was elevated at one month, two months, and six months. COLA1 and vimentin levels all peaked at six months. Matrix metalloproteinase and TIMP1 were also elevated at different months. Collectively, scar AMs can effectively promote wound healing and vascularization. Mature scar AMs have a better regeneration effect.

Clinical guideline on topical growth factors for skin wounds

An increased number of patients with skin wounds have been witnessed in the past decades. Among the various kinds of treatments for skin wounds, topical exogenous growth factors are indispensable and have been used in many countries. However, whether they have reliable effects remains controversial, and their application for skin wound treatment needs to be further standardized and optimized in terms of socio-economic considerations. Thus, the Chinese Burn Association developed this guideline indicating efficacy, application details, adverse reactions and precautions of five clinically common topical growth factors using the Grading of Recommendations Assessment Development and Evaluation method to promote the rational application of topical exogenous growth factors in skin wounds and to benefit more patients.

Immune Cell Therapies to Improve Regeneration and Revascularization of Non-Healing Wounds

With the increased prevalence of chronic diseases, non-healing wounds place a significant burden on the health system and the quality of life of affected patients. Non-healing wounds are full-thickness skin lesions that persist for months or years. While several factors contribute to their pathogenesis, all non-healing wounds consistently demonstrate inadequate vascularization, resulting in the poor supply of oxygen, nutrients, and growth factors at the level of the lesion. Most existing therapies rely on the use of dermal substitutes, which help the re-epithelialization of the lesion by mimicking a pro-regenerative extracellular matrix. However, in most patients, this approach is not efficient, as non-healing wounds principally affect individuals afflicted with vascular disorders, such as peripheral artery disease and/or diabetes. Over the last 25 years, innovative therapies have been proposed with the aim of fostering the regenerative potential of multiple immune cell types. This can be achieved by promoting cell mobilization into the circulation, their recruitment to the wound site, modulation of their local activity, or their direct injection into the wound. In this review, we summarize preclinical and clinical studies that have explored the potential of various populations of immune cells to promote skin regeneration in non-healing wounds and critically discuss the current limitations that prevent the adoption of these therapies in the clinics.

Management and Outcome of Feet Deep Frostbite Injury (III and IV Degrees): A Series Report of 36 Cases

Deep feet frostbite is a severe trauma and often leads to amputation due to full-thickness skin necrosis and subcutaneous tissue damage. A retrospective analysis was performed between June 2013 and June 2019 to review the management measures and outcomes of clinical treatment, and available data had been collected including demographic characteristics, risk factors, and injury environment record. Treatment protocols, wound management, and outcomes were also presented. There were 36 patients diagnosed with deep feet frostbite with a mean age of 51.5 years; the ratio for male to female is 5:1. Drunk and mental disorders were the main risk behaviors for frostbite occurrence. As for the injury environment, mean temperature and wind speed were -20.5 °C and 3.3 m/s, respectively. Fourteen cases achieved wound healing without surgery intervention, 5 cases received skin graft, and 17 cases received amputation. Most amputations (12 cases) were restricted at toe level; only 1 case received whole feet amputation. Our finding indicated that feet deep frostbite in our hospital showed a male predominant and older age including various risk behaviors and coexistence risk factors. Clinical management based on pathology mechanism needs further improvement, as the amputation rate was still high. How to avoid amputation and lower the amputation level are the focus of future efforts.

Effectiveness of recombinant human granulocyte macrophage colony-stimulating factor for treating deep second-degree burns: a systematic review and meta-analysis

Introduction

It is uncertain whether treatment by recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) can promote healing of deep second-degree burns. This meta-analysis aimed to systematically review and assess randomised controlled trials (RCTs) that investigated the efficacy and safety of rhGM-CSF for treating deep second-degree burns.

Methods

This meta-analysis conformed to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement. The PubMed, Cochrane Library, Medline and Embase databases and relevant references were systematically searched for RCTs (published up to November 2019). Main outcome measures included the wound healing rate, wound healing time and average optical densities of the vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF). We performed a meta-analysis using fixed or random effects models.

Results

Seven RCTs comprising 982 patients with 1184 burns (652 patients received rhGM-CSF vs 532 controls) were included. Compared with standard wound care alone, the use of rhGM-CSF significantly reduced wound healing time by 4.77 days (weighted mean difference=−4.77; 95% CI −6.45 to −3.09; p<0.001) and significantly increased the wound healing rate on days 7, 10, 14 and 20 by 6.46%, 19.78%, 17.07% and 11.38%, respectively. There was no significant difference between the groups in the wound healing rate on day 28 and average optical densities of VEGF and FGF. No systematic adverse event occurred. Redder, more swollen and painful wounds were reported after using rhGM-CSF compared with the control.

Conclusions

rhGM-CSF could be effective and safe for treating deep second-degree burns.

Icariin-Loaded Polyvinyl Alcohol/Agar Hydrogel: Development, Characterization, and In Vivo Evaluation in a Full-Thickness Burn Model

Tissue regeneration has become a promising strategy for repairing damaged skin tissues. Among the hydrogels for tissue regeneration applications, topical hydrogels have demonstrated great potential for use as 3D-scaffolds in the burn wound healing process. Currently, no report has been published specifically on icariin-loaded polyvinyl alcohol (PVA)/agar hydrogel on full-thickness burn wounds. In the present study, burn tissue regeneration based on biomimetic hydrogel scaffolds was used for repairing damaged extracellular matrix. Furthermore, a skin burn model was developed in rats, and the icariin-loaded PVA/agar hydrogels were implanted into the damaged portions. The regeneration of the damaged tissues with the help of the icariin-loaded hydrogel group exhibited new translucent skin tissues and repaired extracellular matrix, indicating that the hydrogel can enhance the wound healing process. Moreover, characterization studies such as X-ray diffraction, Fourier-transformed infrared spectroscopy, and differential scanning calorimetry reported the extent of compatibility between icariin and its polymers. Results of the field emission scanning electron microscopy images revealed the extent of the spread of icariin within the polymer-based hydrogel. Furthermore, the wound healing potential, confirmed by histopathological and histochemical findings at the end of 21 days, revealed the visual evidence for the biomimetic property of icariin-loaded PVA/agar hydrogel scaffolds with the extracellular matrix for tissue regeneration.

Nanocrystalline cellulose-hyaluronic acid composite enriched with GM-CSF loaded chitosan nanoparticles for enhanced wound healing

In recent years, applications of biopolymers such as hyaluronic acid (HA) for wound dressing have attracted more attention. However, the poor mechanical properties of HA-based wound dressings limit their clinical applications. Incorporation of reinforcing agents such as nanocrystalline cellulose (CNC) in HA-based wound dressings can improve their mechanical properties. In addition, controlled delivery of growth factors to the wound site using nanoparticles can significantly improve the healing process. In this study, we focus on development and characterization of a novel CNC reinforced HA-based composite containing chitosan nanoparticles loaded with GM-CSF (CNC-HA/GM-CSF-Chi-NPs composite) as an effective wound dressing. CNC-HA/GM-CSF-Chi-NPs composite showed some physicochemical characteristics such as appropriate mechanical properties, high swelling capacity (swelling ratio: 2622.1% ± 35.2%) and controlled release of GM-CSF up to 48 h which make it an excellent candidate for wound dressing. In vivo investigation showed that, after 13 d, the wounds covered with CNC-HA/GM-CSF-Chi-NPs composite could reach to nearly full wound closure and complete re-epithelialization compared to the normal saline treated wounds which exhibited nearly 70% of wound size reduction. Furthermore, the CNC-HA/GM-CSF-Chi-NPs composite treated wounds exhibited significantly lower inflammatory reaction, enhanced re-epithelialization and improved granulation tissue formation compared with CNC-HA/Chi-NPs composite treated wound; it might be due to positive effects of GM-CSF on the wound healing process. Our results suggest that CNC-HA/GM-CSF-Chi-NPs composite can be potentially applied in clinical practice for wound treatment.

Systematic review of clinical outcome reporting in randomised controlled trials of burn care

INTRODUCTION

Systematic reviews collate trial data to provide evidence to support clinical decision-making. For effective synthesis, there must be consistency in outcome reporting. There is no agreed set of outcomes for reporting the effect of burn care interventions. Issues with outcome reporting have been identified, although not systematically investigated. This study gathers empirical evidence on any variation in outcome reporting and assesses the need for a core outcome set for burn care research.

METHODS

Electronic searches of four search engines were undertaken from January 2012 to December 2016 for randomised controlled trials (RCTs), using medical subject headings and free text terms including 'burn', 'scald' 'thermal injury' and 'RCT'. Two authors independently screened papers, extracted outcomes verbatim and recorded the timing of outcome measurement. Duplicate outcomes (exact wording ± different spelling), similar outcomes (albumin in blood, serum albumin) and identical outcomes measured at different times were removed. Variation in outcome reporting was determined by assessing the number of unique outcomes reported across all included trials. Outcomes were classified into domains. Bias was reduced using five researchers and a patient working independently and together.

RESULTS

147 trials were included, of which 127 (86.4%) were RCTs, 13 (8.8%) pilot studies and 7 (4.8%) RCT protocols. 1494 verbatim clinical outcomes were reported; 955 were unique. 76.8% of outcomes were measured within 6 months of injury. Commonly reported outcomes were defined differently. Numbers of unique outcomes per trial varied from one to 37 (median 9; IQR 5,13). No single outcome was reported across all studies demonstrating inconsistency of reporting. Outcomes were classified into 54 domains. Numbers of outcomes per domain ranged from 1 to 166 (median 11; IQR 3,24).

CONCLUSIONS

This review has demonstrated heterogeneity in outcome reporting in burn care research which will hinder amalgamation of study data. We recommend the development of a Core Outcome Set.

PROSPERO REGISTRATION NUMBER

CRD42017060908.

Flaminal® versus Flamazine® in the treatment of partial thickness burns: A randomized controlled trial on clinical effectiveness and scar quality (FLAM study)

Although partial thickness burns are the most frequently reported burn injuries, there is no consensus on the optimal treatment. The objective of this study was to compare the clinical effectiveness and scar quality of Flaminal® Forte to silver sulfadiazine (Flamazine®) in the treatment of partial thickness burns. In this two‐arm open label multicenter randomized controlled trial, adult patients with acute partial thickness burns and an affected total body surface area of less than 30% were randomized between Flaminal® Forte and Flamazine® and followed for 12 months. Dressing changes in the Flamazine® group were performed daily, and in the Flaminal® group during the first 3 days post burn and thereafter every other day until complete wound healing or surgery. Forty‐one patients were randomly allocated to Flaminal® Forte and 48 patients to Flamazine®. The primary outcome was time to wound healing, which did not differ between the groups: median 18 days with Flaminal® Forte (range 8–49 days) versus 16 days with Flamazine® (range 7–48 days; p = 0.24). Regarding the secondary outcomes during hospital admission, there were no statistically significant differences between the groups concerning need for surgery, pain scores, pruritus, or pain‐related and anticipatory anxiety. More patients in the Flaminal® group developed wound colonization (78% versus 32%, p < 0.001), but the treatment groups did not differ regarding the incidence of local infections and use of systemic antibiotics. In terms of scar quality, no statistically significant differences between both treatment groups were found regarding subjective scar assessment (Patient and Observer Scar Assessment Scale (POSAS)), scar melanin and pigmentation (DermaSpectrometer®), and scar elasticity and maximal extension (Cutometer®) during 12 month postburn. In conclusion, time to wound healing did not differ, but the use of Flaminal® Forte seemed favorable because less dressing changes are needed which lowers the burden of wound care.

Sanshool improves UVB-induced skin photodamage by targeting JAK2/STAT3-dependent autophagy

Ultraviolet radiation is markedly increased because of pollution and the depletion of the stratospheric ozone layer. Excessive exposure to sunlight can negatively affect the skin, resulting in sunburn, photo-aging, or skin cancer. In this study, we first determined the photoprotective effect of sanshool, a major component in Zanthoxylum bungeanum, on UVB-irradiated responses in human dermal fibroblasts (HDFs) and nude mouse. We found that sanshool treatment can protect cells against the effects of UVB irradiation by (i) increasing cell viability, (ii) inhibiting MMP expression, and (iii) inducing autophagy. We also used the recombinant CSF2 or anti-CSF2 antibody co-cultured with human dermal fibroblasts (HDFs) and found that CSF2 contributes to sanshool-induced autophagy. Sanshool hindered the UVB-induced activation of JAK2-STAT3 signaling in HDFs, thereby inhibiting the expression of MMPs and activation of autophagic flux. Exposure of the dorsal skin of hairless mice to UVB radiation and subsequent topical application of sanshool delayed the progression of skin inflammation, leading to autophagy and inhibiting the activation of JAK2-STAT3 signaling. These results provide a basis for the study of the photoprotective effect of sanshool and suggest that it can be potentially used as an agent against UVB-induced skin damage in humans.

Advancements in Regenerative Strategies Through the Continuum of Burn Care

Burns are caused by several mechanisms including flame, scald, chemical, electrical, and ionizing and non-ionizing radiation. Approximately half a million burn cases are registered annually, of which 40 thousand patients are hospitalized and receive definitive treatment. Burn care is very resource intensive as the treatment regimens and length of hospitalization are substantial. Burn wounds are classified based on depth as superficial (first degree), partial-thickness (second degree), or full-thickness (third degree), which determines the treatment necessary for successful healing. The goal of burn wound care is to fully restore the barrier function of the tissue as quickly as possible while minimizing infection, scarring, and contracture. The aim of this review is to highlight how tissue engineering and regenerative medicine strategies are being used to address the unique challenges of burn wound healing and define the current gaps in care for both partial- and full-thickness burn injuries. This review will present the current standard of care (SOC) and provide information on various treatment options that have been tested pre-clinically or are currently in clinical trials. Due to the complexity of burn wound healing compared to other skin injuries, burn specific treatment regimens must be developed. Recently, tissue engineering and regenerative medicine strategies have been developed to improve skin regeneration that can restore normal skin physiology and limit adverse outcomes, such as infection, delayed re-epithelialization, and scarring. Our emphasis will be centered on how current clinical and pre-clinical research of pharmacological agents, biomaterials, and cellular-based therapies can be applied throughout the continuum of burn care by targeting the stages of wound healing: hemostasis, inflammation, cell proliferation, and matrix remodeling.

Topically administered rhGM-CSF affects PPARβ expression in the stasis zone

Using a rat comb thermal damage model, we investigated the effects of topically administered recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on peroxisome proliferator-activated receptor PPARβ expression. We created bilateral comb scald models on the backs of fifty Sprague-Dawley rats. The left sides of the backs served as the experimental group and the right sides served as the control group. The experimental group received topically applied rhGM-CSF hydrogel and the control group did not. The survival situations of the stasis zones were compared between the experimental and control groups on the 1st, 3rd, 7th, 14th and 21st post-burn days. Tissues from the surviving stasis zones of both groups were collected at different time-points. Reverse transcriptase-polymerase chain reaction (RT-PCR) and western blotting were used to detect the PPARβ mRNA and protein expression levels. Immunohistochemical methods were applied to detect the localization of PPARβ protein expression. The results showed that, first, the tissue viability numbers for the stasis zones of the experimental group were significantly increased compared with those of the control group. Second, RT-PCR revealed that the PPARβ mRNA expression first increased and then gradually declined in both groups. At all time-points, the expression level in the experimental group was increased compared with that in the control group and the highest expression levels were observed in both groups on the 3rd post-burn day. Third, western blot analysis revealed that the PPARβ protein expression in both groups increased after thermal damage and then gradually decreased. PPARβ protein expression in the experimental group was greater than that in the control group, and the highest expression quantities in both groups were observed on the 3rd post-burn day. In conclusion, rhGM-CSF hydrogel effectively promotes the expression of PPARβ, and the hydrogel had a specific protective effect for the stasis zone.

Epidemiology of pediatric burns in southwest China from 2011 to 2015

BACKGROUND

Burns are a major form of injury in children worldwide. This study aimed to investigate the epidemiology, outcome, cost and risk factors of pediatric burns in southwest China.

METHODS

This retrospective study was performed at the Institute of Burn Research of the Third Military Medical University from 2011 to 2015. Data, including demographic, injury-related, and clinical data and patient outcome, were collected from medical records.

RESULTS

A total of 2478 children with burns (58.03% boys), accounting for 39.2% of total burn patients, were included. The average age of the burn patients was 2.86±2.86years, and most patients (85.55%) were under five years old. The incidence of burns peaked in January, February and May. Scald burns were the most frequent (79.06%), followed by flame burns (14.0%) and electrical burns (3.35%). Limbs were the most common burn sites (69.73%), and the average total body surface area (TBSA) was 11.57±11.61%. The percentage of children who underwent operations and the number of operations were significantly increased in cases of electrical burns, the older-age group, a larger TBSA and full-thickness burns. Six deaths were recorded, yielding a mortality of 0.24%. The median length of stay and cost were 14days and 9541 CNY, respectively, and the major risk factors for length of stay and cost were the TBSA, number of operations, full-thickness burns and outcome.

CONCLUSIONS

In southwest China, among children under five years old, scald and flame burns should become the key prevention target, and future prevention strategies should be based on related risk factors.

Effects of Granulocyte-Macrophage Colony-Stimulating (GM-CSF) Factor on Corneal Epithelial Cells in Corneal Wound Healing Model

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic cytokine that activates granulocyte and macrophage cell lineages. It is also known to have an important function in wound healing. This study investigated the effect of GM-CSF in wound healing of human corneal epithelial cells (HCECs). We used human GM-CSF derived from rice cells (rice cell-derived recombinant human GM-CSF; rhGM-CSF). An in vitro migration assay was performed to investigate the migration rate of HCECs treated with various concentrations of rhGM-CSF (0.1, 1.0, and 10.0 μg/ml). MTT assay and flow cytometric analysis were used to evaluate the proliferative effect of rhGM-CSF. The protein level of p38MAPK was analyzed by western blotting. For in vivo analysis, 100 golden Syrian hamsters were divided into four groups, and their corneas were de-epithelialized with alcohol and a blade. The experimental groups were treated with 10, 20, or 50 μg/ml rhGM-CSF four times daily, and the control group was treated with phosphate-buffered saline. The corneal wound-healing rate was evaluated by fluorescein staining at the initial wounding and 12, 24, 36, and 48 hours after epithelial debridement. rhGM-CSF accelerated corneal epithelial wound healing both in vitro and in vivo. MTT assay and flow cytometric analysis revealed that rhGM-CSF treatment had no effects on HCEC proliferation. Western blot analysis demonstrated that the expression level of phosphorylated p38MAPK increased with rhGM-CSF treatment. These findings indicate that rhGM-CSF enhances corneal wound healing by accelerating cell migration.

Polymeric hydrogels for burn wound care: Advanced skin wound dressings and regenerative templates

Wound closure represents a primary goal in the treatment of very deep and/or large wounds, for which the mortality rate is particularly high. However, the spontaneous healing of adult skin eventually results in the formation of epithelialized scar and scar contracture (repair), which might distort the tissues and cause lifelong deformities and disabilities. This clinical evidence suggests that wound closure attained by means of skin regeneration, instead of repair, should be the true goal of burn wound management. The traditional concept of temporary wound dressings, able to stimulate skin healing by repair, is thus being increasingly replaced by the idea of temporary scaffolds, or regenerative templates, able to promote healing by regeneration. As wound dressings, polymeric hydrogels provide an ideal moisture environment for healing while protecting the wound, with the additional advantage of being comfortable to the patient, due to their cooling effect and non-adhesiveness to the wound tissue. More importantly, recent advances in regenerative medicine demonstrate that bioactive hydrogels can be properly designed to induce at least partial skin regeneration in vivo. The aim of this review is to provide a concise insight on the key properties of hydrogels for skin healing and regeneration, particularly highlighting the emerging role of hydrogels as next generation skin substitutes for the treatment of full-thickness burns.

Growth factor therapy in patients with partial-thickness burns: a systematic review and meta-analysis

Growth factor (GF) therapy has shown promise in treating a variety of refractory wounds. However, evidence supporting its routine use in burn injury remains uncertain. We performed this systematic review and meta-analysis assessing randomised controlled trials (RCTs) to investigate efficacy and safety of GFs in the management of partial-thickness burns. Electronic searches were conducted in PubMed and the Cochrane databases. Endpoint results analysed included wound healing and scar formation. Thirteen studies comprising a total of 1924 participants with 2130 wounds (1131 GF receiving patients versus 999 controls) were identified and included, evaluating the effect of fibroblast growth factor (FGF), epidermal growth factor (EGF) and granulocyte macrophage-colony stimulating factor (GM-CSF) on partial-thickness burns. Topical application of these agents significantly reduced healing time by 5·02 (95% confidence interval, 2·62 to 7·42), 3·12 (95% CI, 1·11 to 5·13) and 5·1 (95% CI, 4·02 to 6·18) days, respectively, compared with standard wound care alone. In addition, scar improvement following therapy with FGF and EGF was evident in terms of pigmentation, pliability, height and vascularity. No significant increase in adverse events was observed in patients receiving GFs. These results suggested that GF therapy could be an effective and safe add-on to standard wound care for partial-thickness burns. High-quality, adequately powered trials are needed to further confirm the conclusion.

Granulocyte/macrophage colony-stimulating factor influences angiogenesis by regulating the coordinated expression of VEGF and the Ang/Tie system

Granulocyte/macrophage colony-stimulating factor (GM-CSF) can accelerate wound healing by promoting angiogenesis. The biological effects of GM-CSF in angiogenesis and the corresponding underlying molecular mechanisms, including in the early stages of primitive endothelial tubule formation and the later stages of new vessel maturation, have only been partially clarified. This study aimed to investigate the effects of GM-CSF on angiogenesis and its regulatory mechanisms. Employing a self-controlled model (Sprague-Dawley rats with deep partial-thickness burn wounds), we determined that GM-CSF can increase VEGF expression and decrease the expression ratio of Ang-1/Ang-2 and the phosphorylation of Tie-2 in the early stages of the wound healing process, which promotes the degradation of the basement membrane and the proliferation of endothelial cells. At later stages of wound healing, GM-CSF can increase the expression ratio of Ang-1/Ang-2 and the phosphorylation of Tie-2 and maintain a high VEGF expression level. Consequently, pericyte coverages were higher, and the basement membrane became more integrated in new blood vessels, which enhanced the barrier function of blood vessels. In summary, we report here that increased angiogenesis is associated with GM-CSF treatment, and we indicate that VEGF and the Ang/Tie system may act as angiogenic mediators of the healing effect of GM-CSF on burn wounds.

Wound dressings: selecting the most appropriate type

Appropriate wound dressing selection is guided by an understanding of wound dressing properties and an ability to match the level of drainage and depth of a wound. Wounds should be assessed for necrosis and infection, which need to be addressed prior to selecting an ideal dressing. Moisture-retentive dressings include films, hydrogels, hydrocolloids, foams, alginates, and hydrofibers and are useful in a variety of clinical settings. Antimicrobial-impregnated dressings can be useful in wounds that are superficially infected or are at higher risk for infection. For refractory wounds that need more growth stimulation, tissue-engineered dressings have become a viable option in the past few decades, especially those that have been approved for burns, venous ulcers, and diabetic ulcers. As wounds heal, the ideal dressing type may change, depending on the amount of exudate and depth of the wound; thus success in wound dressing selection hinges on recognition of the changing healing environment.