Scars

Promoting scarless wound closure utilizing an injectable thermosensitive hydrogel with anti-inflammatory, antioxidant, and scar formation inhibiting properties

Skin trauma, surgery, or burns can result in non-functional scar tissue, causing significant physiological and psychological harm to patients. Therefore, there is an urgent need for a treatment strategy that promotes rapid wound healing and suppresses scar formation. In this study, we developed a facile and injectable composite hydrogel system (PF-127@ERD) loaded with eriodictyol, which exhibits efficient sustained release of the scar-inhibiting compound at different stages of wound healing to facilitate rapid and scarless closure. Our findings revealed that PF-127@ERD not only stops bleeding and reduces local oxidative stress damage in skin wounds but also regulates the inflammatory microenvironment by inhibiting the expression of relevant inflammatory factors while promoting fibroblast migration. Furthermore, PF-127@ERD inhibits excessive collagen deposition and regulates the expression of genes associated with scar formation, thereby promoting scar-free wound healing. In a rat model of full-layer skin defects, skin wound tissue treated with PF-127@ERD healed faster, exhibited more orderly collagen alignment, and showed reduced scar tissue formation compared to other groups. This process may be due to its inhibition of ferroptosis-related pathways. Therefore, this straightforward hydrogel system based on the skin repair stage (PF-127@ERD) holds great potential for scarless wound healing.

Feasibility of calcium hydroxyapatite (Radiesse®) for improving the biomechanical properties of facial burn scars: A pilot study

Background

Effective treatments for facial burn scars remain limited, emphasizing the need for innovative therapeutic approaches. This study explored the feasibility of the use of calcium hydroxyapatite (CaHA, Radiesse®) as a treatment to improve the biomechanical properties of facial burn scars.

Objective

To evaluate the potential effects of CaHA injections on the biomechanical properties of facial burn scars and to compare these effects with those of untreated skin.

Methods

A prospective longitudinal feasibility study was conducted with 13 patients who had mature facial scars (2-5 years) covering more than 90% of the face, including hypertrophic, atrophic, and/or keloid scars. The forehead, cheek, and jaw areas were measured before treatment (baseline control) and at 2, 4, and 6 months after CaHA application, resulting in 312 measurements. CaHA was injected subdermally on one side of the face, with the opposite side serving as a control. Biomechanical properties were assessed via a Cutometer MPA 580 alongside clinical assessments, photography, and validated scar scales (Vancouver Scar Scale and Patient and Observer Scar Assessment Scale).

Results

Preliminary findings suggest that CaHA injections may improve skin extensibility, elasticity, viscoelasticity, hydration, erythema, and pigmentation in the forehead, cheek, and jaw areas. These observations were supported by visual assessments and scale evaluations.

Conclusion

This feasibility study indicated that subdermal CaHA injections have potential as a noninvasive approach for improving the biomechanical properties of facial burn scars. However, further studies with larger sample sizes and long-term follow-up are needed to confirm these findings.

Have the recent advancements in wound repair and scar management technology improved the quality of life in burn patients?

BACKGROUND

The negative physical and psychosocial impact of scars, in particular burn scars, has been well documented. Altered personal appearance together with impaired function related to pain, heat intolerance, and contracture formation may last a lifetime and eventually can lead to low self-esteem and poor social and psychological adjustments. Though most patients recover within the first years and many report generally good life satisfaction and moderate quality of life (QoL), some severely burned patients continue to report impaired QoL almost 10 years after injury. It is repeatedly mentioned in the literature that patients' QoL and health-related quality of life (HRQoL) can be improved by improving wound healing and burn scar quality. Determining whether advances in burn wound healing and scar management modalities are positively impacting the lives of surviving patients is the aim of this review.

METHODS

A systematic literature review was used to identify studies measuring QoL of patients surviving severe burn injuries following various interventions to improve burn wound healing and scar quality.

RESULTS

A limited number of studies was identified. Given the limited available data, a narrative review approach including qualitative studies and reviews in addition to identifying common themes, trends, and gaps in the existing literature was deemed more appropriate for a comprehensive analysis.

CONCLUSION

The assumption that progress made in recent decades to improve burn wound healing and scar quality would improve QoL remains largely hypothetical. Except for functional release of burn scar contractures, improved scar aesthetic quality does not necessarily translate into improved QoL of surviving patients. Well-designed comparative studies are largely lacking.

Exosome-like vesicles encapsulated with specific microRNAs accelerate burn wound healing and ameliorate scarring

Burn injuries are prevalent, yet effective treatments remain elusive. Exosomes derived from mesenchymal stem cells (MSC-Ex) possess remarkable pro-regenerative properties for wound healing. Despite their potential, the challenge of mass production limits their clinical application. To address this, preparing exosome-like vesicles has become an international trend. In this study, 28 key microRNAs (miRNAs) with significant pro-proliferation, anti-inflammation, and anti-fibrosis functions were screened from MSC-Ex. These miRNAs were encapsulated into liposomes and then hybridized with extracellular vesicles derived from watermelon to create synthetic exosome-like vesicles. The fabricated vesicles exhibited similar particle size and zeta potential to MSC-Ex, demonstrating high serum stability and effectively resisting the degradation of miRNA by RNase. They were efficiently internalized by cells and enabled a high rate of lysosomal escape for miRNAs post cellular uptake, thereby effectively exerting their pro-proliferative, anti-inflammatory, and anti-fibrotic functions. Further experiments demonstrated that these vesicles efficiently accelerated burn wound healing and reduced scarring, with effects comparable to those of natural MSC-Ex. Based on these findings, the exosome-like vesicles fabricated in this study present a promising alternative to MSC-Ex in burn wound treatment.

Electret-Inspired Charge-Injected Hydrogel for Scar-Free Healing of Bacterially Infected Burns Through Bioelectrical Stimulation and Immune Modulation

In this study, an electret-inspired, charge-injected hydrogel called QOSP hydrogel (QCS/OD/SDI/PANI/PS/Plasma) that promotes scar-free healing of bacteria-infected burns through bioelectrical stimulation and immune modulation, is presented. The hydrogel, composed of quaternized chitosan (QCS), oxidized dextran (OD), sulfadiazine (SDI), polystyrene (PS), and polyaniline nanowires (PANI), forms a conductive network capable of storing and releasing electric charges, emulating an electret-like mechanism. This structure delivers bioelectrical signals continuously, enhancing wound healing by regulating immune responses and minimizing fibrosis. In a mouse model of second-degree burns infected with Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA), the hydrogel accelerates wound healing by 32% and reduces bacterial load by 60%, significantly inhibited scar formation by 40% compared to controls. QOSP hydrogel modulates the Th1/Th2 immune balance toward a Th1-dominant antifibrotic state through quaternized chitosan, thereby reducing collagen deposition by 35%. Electro-dielectric characterization reveals a dielectric constant of 6.2, a 34% improvement in conductivity (3.33 × 10-5 S/m) and a 30 °C increase in thermal stability. Proteomic analysis highlights a 50% down-regulation of pro-inflammatory and pro-fibrotic pathways, suggesting a controlled immune response conducive to scar-free healing. This study underscores the potential of bioelectrically active hydrogels as a novel approach for treating infected wounds prone to scarring.

Research progress on collagen secretion mechanisms in scarring

Scar formation is characterized by dynamic alterations in collagen secretion, which critically determine scar morphology and pathological progression. In fibroblasts, collagen secretion is initiated through cytokine- and integrin-mediated signaling pathway activation, promoting collagen gene transcription. The procollagen polypeptide α chains undergo rigorous post-translational modifications, including hydroxylation and glycosylation, within the endoplasmic reticulum (ER), followed by folding and assembly into triple-helical procollagen. Subsequent intracellular trafficking involves sequential transport of procollagen through the ER, Golgi apparatus, and plasma membrane, accompanied by further structural refinements prior to extracellular secretion. Once secreted, procollagen is enzymatically processed to form mature collagen fibrils, which drive scar tissue remodeling. Recent advances in elucidating collagen secretory regulation have identified pivotal molecular targets, such as transforming growth factor-beta 1 (TGF-β1), prolyl 4-hydroxylase (P4H), heat shock protein 47 (HSP47), and transport and Golgi organization protein 1 (TANGO1), providing novel therapeutic avenues to mitigate pathological scar hyperplasia and enhance regenerative outcomes. This review comprehensively outlines the molecular mechanisms governing collagen secretion during scar formation, with emphasis on signaling cascades, procollagen biosynthesis, intracellular transport dynamics, and post-translational modifications, thereby offering a framework for developing targeted anti-scar therapies.

Targeting PIM1 by Bruceine D attenuates skin fibrosis via myofibroblast ferroptosis

Skin pan-fibrosis diseases-such as hypertrophic scar (HS), keloid scar (KS), and systemic sclerosis (SSc)-pose significant threats to patients' health and quality of life. In this study, the authors conducted both in vivo and in vitro experiments and discovered that the serine/threonine kinase PIM1 is upregulated in the myofibroblasts of human HS, KS, and SSc tissues, as well as in various animal models of skin fibrosis. Overexpression of PIM1 enhanced the profibrotic phenotypes of human hypertrophic scar fibroblasts (HSFs), which serve as key effector cells in the pathogenesis of skin pan-fibrosis diseases. Through high-throughput screening and subsequent laboratory assays, we identified the small molecule Bruceine D (BD) as a direct binder of PIM1. BD promoted ferroptosis in HSFs by selectively suppressing the PIM1-KEAP1-NRF2 pathway through augmented degradation of PIM1. In various in vivo models-including a hypertrophic scar mouse model, a rabbit ear hypertrophic scar model, and a bleomycin (BLM)-induced skin fibrosis mouse model-BD effectively attenuated fibrotic phenotypes. Collectively, these findings demonstrate that PIM1 serves as a common biomarker and therapeutic target for skin pan-fibrosis diseases. BD mitigates skin fibrosis by activating ferroptosis via PIM1 inhibition, highlighting its great translational potential and high promise to be developed to a clinical drug in treating these conditions, especially those with abnormally elevated PIM1 expression.

Fibrosis: cross-organ biology and pathways to development of innovative drugs

Fibrosis is a pathophysiological mechanism involved in chronic and progressive diseases that results in excessive tissue scarring. Diseases associated with fibrosis include metabolic dysfunction-associated steatohepatitis (MASH), inflammatory bowel diseases (IBDs), chronic kidney disease (CKD), idiopathic pulmonary fibrosis (IPF) and systemic sclerosis (SSc), which are collectively responsible for substantial morbidity and mortality. Although a few drugs with direct antifibrotic activity are approved for pulmonary fibrosis and considerable progress has been made in the understanding of mechanisms of fibrosis, translation of this knowledge into effective therapies continues to be limited and challenging. With the aim of assisting developers of novel antifibrotic drugs, this Review integrates viewpoints of biologists and physician-scientists on core pathways involved in fibrosis across organs, as well as on specific characteristics and approaches to assess therapeutic interventions for fibrotic diseases of the lung, gut, kidney, skin and liver. This discussion is used as a basis to propose strategies to improve the translation of potential antifibrotic therapies.

Development of a predictive model for the relationship between serum pan-immunoinflammatory index levels and scar formation in facial burn patients

OBJECTIVES

This study aims to develop a predictive model for scar risk in patients with facial burns using the Pan-Immune Inflammation Value (PIV) and other serological markers.

METHODS

A retrospective cohort study was conducted on 367 patients with facial burns treated at a single institution between June 2021 and June 2023. Patients were categorized based on the presence of the scar 7 days post-treatment. Serum markers, including PIV, TNF-α, IL-10, EPO, TGF-β1, and ICAM-1, were measured. Multivariate logistic regression was employed to identify independent predictors of scar formation. A predictive model was developed and validated using a test set of 144 patients.

RESULTS

Scar formation was associated with elevated levels of TNF-α and ICAM-1, and reduced levels of IL-10, EPO, and TGF-β1, indicating a pro-inflammatory profile. Patients with scars showed higher symptom severity, emotional distress, and functional impairment. The predictive model, incorporating these markers, achieved an AUC of 0.815 in the training set and 0.845 in the test set, demonstrating good predictive performance.

CONCLUSION

Elevated pro-inflammatory markers and altered PIV levels were significant predictors of scar formation in patients with facial burns.

Orthogonal upconversion nanocarriers for combined photodynamic therapy and precisely triggered gene silencing in combating keloids

Keloids are pathological scars characterized by excessive fibroblast proliferation, abnormal collagen deposition, and chronic inflammation, which often result in high recurrence rates and limited treatment success. Targeting BACH1 with gene therapy has shown promise in regulating fibroblast activity and reducing inflammation. However, effective delivery systems for targeted gene therapy in keloids remain a major challenge. Here, we develop a novel nanocarrier platform based on orthogonal upconversion nanoparticles (OUNCs) to achieve spatiotemporal silencing of BACH1 and combined photodynamic therapy (PDT). The OUNCs are composed of orthogonal upconversion nanoparticles (UCNPs), photosensitizer (Rose Bengal), ROS-sensitive diselenide bonds (SeSe), therapeutic siBACH1, and an active targeting moiety (hyaluronic acid) to specifically target keloid fibroblasts (KFs). We demonstrate that the OUNCs can effectively induce KFs apoptosis, inhibit KFs proliferation, and reduce M2 macrophages recruitment by modulating the Rap1/MEK/ERK signaling pathway. Our study represents a breakthrough in precision therapy for keloids, providing a promising platform that integrates siBACH1-based gene therapy with NIR light-triggered PDT.

Electrospinning in promoting chronic wound healing: materials, process, and applications

In the field of wound treatment, chronic wounds pose a significant burden on the medical system, affecting millions of patients annually. Current treatment methods often fall short in promoting effective wound healing, highlighting the need for innovative approaches. Electrospinning, a technique that has garnered increasing attention in recent years, shows promise in wound care due to its unique characteristics and advantages. Recent studies have explored the use of electrospun nanofibers in wound healing, demonstrating their efficacy in promoting cell growth and tissue regeneration. Researchers have investigated various materials for electrospinning, including polymers, ceramics, carbon nanotubes (CNTs), and metals. Hydrogel, as a biomaterial that has been widely studied in recent years, has the characteristics of a cell matrix. When combined with electrospinning, it can be used to develop wound dressings with multiple functions. This article is a review of the application of electrospinning technology in the field of wound treatment. It introduces the current research status in the areas of wound pathophysiology, electrospinning preparation technology, and dressing development, hoping to provide references and directions for future research.

Long-Term Outcomes of a Cultured Autologous Dermo-Epidermal Skin Substitute in Children: 5-Year Results of a Phase I Clinical Trial

Limited donor sites and poor long-term outcomes with standard treatment for large skin defects remain a huge problem. An autologous, bilayered, laboratory-grown skin substitute (denovoSkin) was developed to overcome this problem and has shown to be safe in 10 pediatric patients in a Phase I clinical trial after transplantation. The goal of this article was to report on 48-month long-term results. The pediatric participants of the phase I clinical trial were followed up at yearly visits up to 5 years after transplantation. Safety parameters, including the occurrence of adverse events, possible deviations of vital signs, and changes in concomitant therapy as well as additional parameters regarding skin stability, scar quality, and tumor formation, were assessed. Furthermore, scar maturation was photographically documented. Of the 10 patients treated with denovoSkin in this phase I clinical trial, 7 completed the 5-year follow-up period. Skin substitutes continued to be deemed safe, remained stable, and practically unchanged, with no sign of fragility and no tumor formation at clinical examination. Scar quality, captured using the Patient and Observer Scar Assessment Scale, was evaluated as close to normal skin. Transplantation of this laboratory-grown skin substitute in children is to date considered safe and shows encouraging functional and aesthetical long-term results close to normal skin. These results are promising and highlight the potential of a life-saving therapy for large skin defects. A multicentre, prospective, randomized, phase II clinical trial is currently ongoing to further evaluate the safety and efficacy of this novel skin substitute. Clinicaltrials.gov identifier NCT02145130.

Pathological-microenvironment responsive injectable GelMA hydrogel with visualized biodegradation for pressure-assisted treatment of hypertrophic scars

Intralesional injection of 5-fluorouracil for the clinical treatment of hypertrophic scars (HS) remains challenging due to its short half-life, as well as the absence of evidence-based dosage and frequency injection guidelines. Herein, we developed a matrix metalloproteinases (MMPs)/reactive oxygen species (ROS)-responsive injectable prodrug hydrogel (GFP) that exhibits sustained drug release and fluorescence imaging capability, aiming to facilitate the optimization of injection dosage and frequency in HS treatment. The GFP hydrogel comprises gelatin methacryloyl and pendant methacryloyl-decorated tetrapeptide (PPPK) with 5-fluorouracil acetic acid/rhodamine B at the N-terminus. After intralesional injection and blue light irradiation, the crosslinked hydrogel in HS lesions exhibited long-term sustained drug release by consuming overexpressed MMPs and ROS, which could be visualized by fluorescence imaging to guide injection frequency for HS treatment. In addition, due to its exceptional swelling and mechanical properties, the GFP hydrogel exerts a certain pressure inside the HS tissues, functioning as an adjunctive therapy to inhibit HS. Our results demonstrate that the GFP hydrogel can promote fibroblast apoptosis, inhibit collagen synthesis, and remodel the microenvironment of HS. This study presents a promising visualized drug delivery platform that potentially guides the optimization of injection frequency and dosage in the treatment of HS.

Subcellular Fractionation and Metaproteogenomic Identification and Validation of Key Differentially Expressed Molecular Targets for Keloid Disease

Keloid disease (KD) is a common connective tissue disorder of unknown aetiopathogenesis with ill-defined treatment. Keloid scars present as exophytic fibroproliferative reticular lesions postcutaneous injury, and even though KD remains neoplastically benign, keloid lesions behave locally aggressive, invasive and expansive. To date, there is limited understanding and validation of biomarkers identified through combined proteomic and genomic evaluation of KD. Therefore, the aim in this study was to identify putative causative candidates in KD by performing a comprehensive proteomics analysis of subcellular fractions as well as the whole cell, coupled with transcriptomics data analysis of normal compared with KD fibroblasts. We then applied novel integrative bioinformatics analysis to demonstrate that NF-kB-p65 (RELA) from the cytosolic fraction and CAPN2 from the whole-cell lysate were statistically significantly upregulated in KD and associated with alterations in relevant key signaling pathways, including apoptosis. Our findings were further confirmed by showing upregulation of both RELA and CAPN2 in KD using flow cytometry and immunohistochemistry. Moreover, functional evaluation using real-time cell analysis and flow cytometry demonstrated that both omeprazole and dexamethasone inhibited the growth of KD fibroblasts by enhancing the rate of apoptosis. In conclusion, subcellular fractionation and metaproteogenomic analyses have identified, to our knowledge, 2 previously unreported biomarkers of significant relevance to keloid diagnostics and therapeutics.

LINC00525 promotes cell proliferation and collagen expression through feedforward regulation of TGF-β signaling in hypertrophic scar fibroblasts

The etiology of hypertrophic scar formation continues to elude researchers, despite advancements in the understanding of skin scarring. Several long non-coding RNAs (lncRNAs) have been implicated in the pathogenesis of hypertrophic scars, yet the role and molecular mechanisms of LINC00525 in this process remain unclear. This study demonstrates that LINC00525 enhances cell proliferation and collagen expression through knockdown and overexpression techniques. Further analysis, including nuclear and cytoplasmic localization studies, RNA pull-down assays, bioinformatics predictions, and PCR validation, reveals that LINC00525 interacts with miR-29a-5p. The downregulation of LINC00525 enhances the expression of miR-29a-5p and suppresses the TGF-β/Smad signaling pathway. Additionally, TGF-β1 induces the upregulation of LINC00525. Collectively, these findings indicate that LINC00525 operates through a feedforward mechanism to regulate TGF-β signaling in hypertrophic scar fibroblasts. This research offers novel insights for the prevention and treatment of scars.

Folate alleviated skin inflammation and fibrosis resulting from impaired homocysteine metabolism

Skin fibrosis, characterized by uncontrolled secretion of extracellular matrix (ECM) proteins such as collagen, can lead to excessive scarring and compromised tissue function. Despite the widespread occurrence of fibrotic diseases, effective therapies are lacking. Recent clinical studies have demonstrated a positive correlation between serum homocysteine (Hcy) levels and the severity of systemic sclerosis. However, it remains unclear whether Hcy accumulation plays a pathogenic role in skin fibrosis. Here, we report that Hcy metabolism in fibroblasts plays a crucial role in regulating the pathogenesis of skin fibrosis. Fibrotic skin fibroblasts exhibited elevated levels of Hcy due to the downregulation of catabolism genes CBS and MTR. Experimental skin fibrosis was induced and exacerbated in mouse skin fibroblasts and tissues through adenoviral knockdown of Cbs or Mtr, whereas overexpression of these catabolic genes mitigated the pathogenesis. Furthermore, exogenous Hcy supplementation induced and aggravated the expression of inflammatory and fibrotic genes, promoting both spontaneous and BLM-induced skin fibrosis. Notably, folate administration enhanced Hcy catabolism and ameliorated skin inflammation and fibrosis by inhibiting JAK2/STAT3 signaling pathway. Collectively, these results indicate that skin fibrosis is associated with Hcy metabolic disorders and suggest that targeting Hcy metabolism or supplementing folate may provide a novel strategy for skin fibrosis.

Investigation on the effects and mechanisms of novel peptide nanofiber gel to promote wound healing of deep second-degree burns in mice

The self-assembled peptide RADA16-I (RADARADARADARADA) has been widely used in biomaterials. However, studies on the practical application of self-assembled peptide hydrogels loaded with bioactive peptides are still insufficient. In this study, we successfully prepared the peptide nanofiber gel RGJ by incorporating the bioactive peptides A8SGLP-1 (G) and Jagged-1 (J) into RADA16-I (R) in specific ratios. The mechanical properties, secondary structure, and microstructure of RGJ were thoroughly characterized using a rheometer, circular dichroism (CD), and transmission electron microscopy (TEM). The results showed that R and RGJ adopted stable β-folded structures at room temperature, and RGJ exhibited a nanofiber mesh structure, confirming its excellent physical properties. Cellular experiments demonstrated that RGJ significantly enhanced the proliferation and migration of HaCaT, L929, and HUVEC cells, with the most pronounced effect observed in HUVEC cells. In the 100 μg/mL RGJ-treated group, cell viability (OD value) reached 1.369, which was significantly higher than that of the control group (0.673) and the R-only group (0.848). The strongest pro-migratory effect was observed in HaCaT cells, with a scratch closure rate of 22.83 %. In vivo experiments showed that the deep second-degree burn wounds of mice in the RGJ gel-treated group healed rapidly by day 17, exhibiting 99.5 % wound closure, compared to 84.02 % in the R gel group, and 73.02 % and 70.97 % in the control and burn cream groups, respectively. Immunohistochemistry and ELISA results further confirmed that RGJ significantly reduced wound and systemic inflammatory responses while promoting the secretion of pro-angiogenic factors VEGF and CD31, revealing its potential mechanism for enhancing burn wound healing. Additionally, RGJ significantly reduced wound scar formation and increased skin collagen deposition, demonstrating a favorable biosafety profile compared to the control group, commercial burn ointment, and the R-only treatment group. In conclusion, the development of the peptide nanofiber gel RGJ holds great potential for wound management applications and lays a foundation for future related research.

Ankyrin repeat domain 1 is dysregulated in keloids and suppresses keloid fibroblast growth, migration, and extracellular matrix deposition

Objective

The etiology and specific pathological mechanisms of keloids remain elusive. Array expression profiling has revealed dysregulation of the transcription cofactor ankyrin repeat domain 1 (ANKRD1) in keloid fibroblasts. The present study focused on examining the expression pattern of ANKRD1 in keloids and assessing its function in human keloid fibroblasts (HKFs).

Material and Methods

Differential mRNA expression profiles in keloid fibroblasts were investigated by analyzing data from gene expression omnibus (GEO) datasets. Immunohistochemistry assays were performed to verify the expression patterns of ANKRD1 and claudin 11 (CLDN11) in keloid tissue samples. Functional studies were conducted by transfecting HKFs with either a small interfering RNA (siRNA) targeting ANKRD1 (siANKRD1) or ANKRD1-overexpressing plasmids. The functional impact of ANKRD1 was assessed using cell proliferation, flow cytometry, and Transwell migration assays. mRNA expression was evaluated using reverse transcription polymerase chain reaction, and protein expression was determined using Western blotting.

Results

Analysis of the GEO series (GSE) GSE44270 revealed eight differentially expressed mRNAs, with ANKRD1 and CLDN11 being the top two downregulated mRNAs. ANKRD1 expression was observed to be lower in keloid tissues than in normal skin tissues, whereas CLDN11 expression showed no significant difference between the two groups. ANKRD1 overexpression suppressed HKF proliferation, migration, and the expression levels of collagen I, fibronectin, matrix metallopeptidase 9, whereas the opposite effects were observed on ANKRD1 knockdown. ANKRD1 did not affect apoptotic cell levels.

Conclusion

ANKRD1 is downregulated in keloids and inhibits the growth, migration, and extracellular matrix deposition of keloid fibroblasts. Thus, ANKRD1 may function as a suppressor in keloid formation.

Combination therapy of pulsed dye laser and ablative fractional carbon dioxide laser for the treatment of pediatric postburn scar: a systematic review

This study aims to determine the effectiveness of combining pulsed dye laser (PDL) and ablative fractional carbon dioxide laser (AFCL) in the treatment of scars in pediatric patients, as well as to identify appropriate treatment parameters, initial treatment timing, and treatment intervals through a systematic literature review. A literature search was conducted between April 6, 2014 and April 6, 2024 in four databases to select studies on the effects of the combination of carbon dioxide fractional laser and pulsed dye laser therapy in children hypertrophic burn scars. This systematic literature review included 497 participants across 8 studies, with individual study sample sizes ranging from 17 to 125 participants. 7 studies reported the gender distribution of participants, with a higher proportion of males (60%, n = 264) than females (40%, n = 170). The average age of the patients was 7.18 years, and scald (62%, n = 235) were identified as the primary cause of scar. The combination therapy of 595 nm PDL and 10,600 nm AFCL significantly improved Vancouver Scar Scale (VSS) / Patient and Observer Scar Assessment Scale (POSAS) score. Study treatment intervals were approximately 1-2 months for simultaneous treatment and 1 month for PDL and 3 months for AFCL for sequential treatment. Two studies investigated the efficacy of early laser therapy (< 3 months), the AFCL laser energy parameters ranged from 30 mJ-50 mJ, significantly lower than the rest of the studies of laser energy parameters, which ranged from 50 mJ-120 mJ. The PDL energy density parameters showed little difference from study to study and were in the range of 5-12 J/cm2. Complications after treatment (4%, n = 22), with rash being the most common (50%, n = 11). Rational use of PDL combined with AFCL (lower laser energy, increase density parameters, shorten treatment intervals (< 1 month)) can safely and effectively treat hypertrophic scars in pediatric burn patients and is superior to single-type laser therapy in efficacy. Significant disorganization was observed among studies suggesting the need to explore high-level evidence-based clinical research that may improve treatment outcomes.

Fraxinellone-mediated targeting of cathepsin B leakage from lysosomes induces ferroptosis in fibroblasts to inhibit hypertrophic scar formation

BACKGROUND

Hypertrophic scar (HS) is a common fibrotic skin disorder characterized by the excessive deposition of extracellular matrix (ECM). Fibroblasts are the most important effector cells involved in HS formation. Currently no satisfactory treatment has been developed.

METHODS

The impact of fraxinellone (FRA) on the proliferation and migration capacity of human hypertrophic scar-derived fibroblasts (HSFs) was assessed by EdU proliferation, wound healing and transwell assays. Quantitative real-time PCR (qRT‒PCR), Western blot (WB), immunofluorescence staining and collagen gel contraction assays were performed to evaluate the collagen production and activation capacity of HSFs. Oxford Nanopore Technologies long-read RNA sequencing (ONT long-read RNA-seq) revealed the occurrence of ferroptosis in HSF and ferroptosis executioner-cathepsin B (CTSB). The mechanisms underlying FRA-induced HSF ferroptosis were examined through fluorescence staining, qRT‒PCR, WB and molecular docking study. The therapeutic efficacy of FRA was further validated in vivo using a rabbit ear scar model.

RESULTS

FRA treatment significantly suppressed the proliferation, migration, collagen production and activation capacity of HSFs. ONT long-read RNA-seq discovered that FRA modulated the expression of transcripts related to ferroptosis and lysosomes. Mechanistically, FRA treatment reduced the protein expression level of glutathione peroxidase 4 (GPX4) and induced the release of CTSB from lysosomes into the cytoplasm. CTSB further induced ferroptosis via spermidine/spermine-N1-acetyltransferase (SAT1)-mediated lipid peroxidation, mitochondrial damage and mitogen-activated protein kinase (MAPK) signalling pathway activation, eventually affecting the function of HSFs. Moreover, FRA treatment attenuated the formation of HS in rabbit ears via CTSB-mediated ferroptosis. The antifibrotic effects of FRA were abrogated by pretreatment with a CTSB inhibitor (CA-074-me).

CONCLUSIONS

This study reveals that FRA ameliorates HS by inducing CTSB leakage from lysosomes, causing SAT1-mediated lipid peroxidation, mitochondrial damage and MAPK signalling pathway activation, thus mediating HSF ferroptosis. Therefore, FRA could be a promising therapeutic agent for treating HS.

Food-Derived Tripeptide-Copper Self-Healing Hydrogel for Infected Wound Healing

The field of infected wound management continues to face challenges, and traditional methods used to cope with wounds include debridement, gauze coverage, medication, and others. Currently, synthetic and natural biomaterials are readily available today, enabling the creation of new wound dressings that substantially enhance wound healing. Considerable attention is being paid to hydrogels based on natural materials, which have good biocompatibility and degradability properties, while exhibiting higher similarity to natural extracellular matrix as compared to synthetic materials. In this study, we extracted the active ingredients of oxidized konjac glucomannan (OKGM) and fresh egg white (EW) from 2 foods, konjac, and egg, respectively, and formed a self-repairing hydrogel based on the cross-linking of a Schiff base. Subsequently, a natural active peptide, glycyl-l-histidyl-l-lysine-Cu (GHK-Cu), was loaded, and an all-natural composite hydrogel dressing, EW/OKGM@GHK-Cu (GEK), was developed. The GEK hydrogel, exhibiting both antibacterial and anti-inflammatory properties, plays a hemostatic role by adhering to tissues and promoting neovascularization and serves as an optimal dressing for skin regeneration. Taken together, GEK hydrogel dressings derived from natural food sources therefore constitute an efficient and cost-effective strategy for managing infected wound healing and have significant potential for clinical application and transformation.

Piezoelectric nanocomposite electrospun dressings: Tailoring mechanics for scar-free wound recovery

Rational wound management and enhancing healing quality are critical in clinical practice. Electrical stimulation therapy (EST) has emerged as a valuable adjunctive treatment due to its safety and cost-effectiveness. Integrating piezoelectric materials into dressings offers a way to miniaturize and personalize electrotherapy, enhancing convenience. To address the impact of physical factors of dressings on wound healing, a nanocomposite piezoelectric electrospun dressing using poly(L-lactic acid) (PLLA) and barium titanate (BaTiO3) was developed. We intentionally exaggerated design flaws to mimic the characteristics of scar extracellular matrix (ECM), including the oriented thick fibers and high Young's modulus. Initially, these dressings promoted fibrosis and hindered functional regeneration. However, when the piezoelectric effect was triggered by ultrasound, the fibrotic phenotype was reversed, leading to scar-free healing with well-regenerated functional structures. This study highlights the significant therapeutic potential of piezoelectric dressings in skin wound treatment and underscores the importance of carefully designing the static physical properties of dressings for optimal efficacy.

Multi-ancestry meta-analysis of keloids uncovers novel susceptibility loci in diverse populations

Keloids are raised scars that grow beyond original wound boundaries, resulting in pain and disfigurement. Reasons for keloid development are not well-understood, and current treatment options are limited. Keloids are more likely to occur in darker-skinned individuals of African and Asian descent than in Europeans. We performed a genome-wide association study (GWAS) examining keloid risk across and within continental ancestry groups, incorporating 7,837 cases and 1,593,009 controls. We detected 21 novel independent loci in the multi-ancestry analysis, including several previously associated with fibroproliferative disorders. Heritability estimates were 6%, 21%, and 34% for the European, East Asian, and African ancestry analyses, respectively. Genetically predicted gene expression and colocalization analyses identified 27 gene-tissue pairs, including nine in skin and fibroblasts. Pathway analysis implicated integrin signaling and upstream regulators involved in cancer, fibrosis, and sex hormone signaling. This investigation nearly quintuples the number of keloid-associated risk loci, illuminating biological processes in keloid pathology.

Real-world effectiveness and safety of bleomycin in patients with keloids and hypertrophic scars: a systematic review and meta-analysis

Pathological scars are classified into hypertrophic scars and keloids, and currently have poor treatment outcomes and high recurrence rates. Bleomycin has received widespread attention in scar treatment in recent years, but there is currently no exploration on its real-world data. PubMed, Embase, and Cochrane databases were searched, and eight retrospective studies on the use of bleomycin for treatment were included, covering a total of 562 patients with keloids and hypertrophic scars. The meta-analysis results revealed that 90% of patients had significant flattening of scars after treatment with bleomycin, 5% had moderate flattening, and 4% had mild flattening. The recurrence rate after treatment was only 3%. The major adverse reaction was hyperpigmentation, with an incidence rate of 8%, and no significant ulcers or skin atrophy were reported. Subgroup analysis showed that the significant flattening rate treated with bleomycin alone was 91%, which was significantly different from the 79% treated with bleomycin in combined with triamcinolone acetonide, but the difference was not statistically significant. In addition, the significant flattening rate was 99% in Western patients and 57% in Asian patients, reflecting the impact of racial differences on treatment outcomes. There was no statistically significant difference in curative effects between males and females (RR: 0.95; P = 0.77). Overall, bleomycin has good curative effect in treating scars and has high safety, especially showing more significant effects in Western populations. However, racial differences, treatment plans, and other factors may affect the therapeutic effect of bleomycin. Future research can further explore the mechanisms of these factors and provide more personalized treatment plans for patients with scar.

pH-responsive hydrogel with dual-crosslinked network of polyvinyl alcohol/boric acid for controlled release of salvianolic acid B: novel pro-regenerative mechanisms in scar inhibition and wound healing

This study investigates a novel pH-responsive hydrogel composed of polyvinyl alcohol (PVA) and boric acid (BA) designed for the controlled release of salvianolic acid B (SAB), addressing the critical challenge of scar formation and skin regeneration. The dual-crosslinked network architecture of the hydrogel exhibits remarkable pH sensitivity, enabling it to achieve a peak SAB release within 48 hours in the acidic microenvironment characteristic of early-stage wound healing. In vitro assessments demonstrated that the PVA-BA-SAB hydrogel significantly inhibits fibroblast activation and mitigates abnormal collagen deposition, effectively preventing excessive scar formation. Transcriptome sequencing reveals the potential role of PVA-BA-SAB hydrogel in balancing TGF-β and Wnt signaling pathways. Furthermore, in vivo studies revealed enhanced tissue regeneration, characterized by improved collagen organization and increased vascularization, as well as the promotion of mature hair follicle development. The hydrogel's biocompatibility, mechanical robustness and adhesive properties were also thoroughly evaluated, confirming its suitability for clinical applications. These findings suggest that the PVA-BA-SAB hydrogel fully exerts the excellent characteristics of biomaterials and maximizes the pharmacological effect of SAB. Our innovative drug delivery system not only facilitates enhanced wound healing but also offers a strategic approach to minimize scarring. This research provides valuable insights into innovative therapeutic strategies for effective wound management and tissue repair.

Hypericum Perforatum Callus Extract-Loaded Composite Hydrogel with Diverse Bioactivities for Enhanced Wound Healing and Fibrosis Prevention

Plant Callus are a valuable source of pluripotent stem cells and bioactive phytochemicals. Meanwhile, the Hypericum perforatum callus extract (HPCE) is particularly rich in compounds such as hyperforin, hypericin, quercetin, and other phenolic and flavonoid derivatives. These phytochemicals exhibit strong antibacterial, antioxidant, anti-inflammatory, and anti-fibrotic properties, making them promising for wound healing. One of the most critical challenges following wound healing is the formation of fibrosis, which can compromise the complex structural integrity of skin. To address this issue, a poly(vinyl alcohol)/chitosan/alginate (PCA) wound dressing loaded with HPCE is developed. This hydrogel dressing features a porous structure with suitable mechanical properties and a high swelling capacity, potentially enhancing its effectiveness in promoting tissue regeneration and wound healing. In vitro studies have confirmed its biocompatibility, cell proliferation, and cell adhesion properties. Additionally, the dressing has demonstrated the ability to inhibit the proliferation of certain antibiotic-resistant bacteria. The in vivo studies revealed the anti-inflammatory properties, promotion of angiogenesis, facilitation of re-epithelialization, and stimulation of collagen deposition of the dressing under investigation. Moreover, the immunohistochemistry analysis of the two key markers, p16 and p53, has shown that the application of the dressing helps prevent fibrosis after wound healing.

Macrophage Polarization: A Novel Target and Strategy for Pathological Scarring

BACKGROUND

Abnormal scarring imposes considerable challenges and burdens on the lives of patients and healthcare system. Macrophages at the wound site are found to be of great concern to overall wound healing. There have been many studies indicating an inextricably link between dysfunctional macrophages and fibrotic scars. Macrophages are not only related to pathogen destruction and phagocytosis of apoptotic cells, but also involved in angiogenesis, keratinization and collagen deposition. These abundant cell functions are attributed to specific heterogeneity and plasticity of macrophages, which also add an extra layer of complexity to correlational researches.

METHODS

This article summarizes current understanding of macrophage polarization in scar formation and several prevention and treatment strategies on pathological scarring related to regulation of macrophage behaviors by utilizing databases such as PubMed, Google Scholar and so on.

RESULTS

There are many studies proving that macrophages participate in the course of wound healing by converting their predominant phenotype. The potential of macrophages in managing hypertrophic scars and keloid lesions have been underscored.

CONCLUSION

Macrophage polarization offers new prevention strategies for pathological scarring. Learning about and targeting at macrophages may be helpful in achieving optimum wound healing.

Sele-targeted siRNA liposome nanoparticles inhibit pathological scars formation via blocking the cross-talk between monocyte and endothelial cells: a preclinical study based on a novel mice scar model

BACKGROUND

Pathological scars (PS) are one of the most common complications in patients with trauma and burns, leading to functional impairments and aesthetic concerns. Mechanical tension at injury sites is a crucial factor in PS formation. However, the precise mechanisms remain unclear due to the lack of reliable animal models.

RESULTS

We developed a novel mouse model, the Retroflex Scar Model (RSM), which induces PS by applying controlled tension to wounds in vivo. RNA sequencing identified significant transcriptome changes in RSM-induced scars. Elevated expression of E-Selectin (Sele) was observed in endothelial cells from both the RSM model and human PS (Keloid) samples. In vitro studies demonstrated that cyclic mechanical stretching (CMS) increased Sele expression, promoting monocyte adhesion and the release of pro-inflammatory factors. Single-cell sequencing analysis from the GEO database, complemented by Western blotting, immunofluorescence, and co-immunoprecipitation, confirmed the role of Sele-mediated monocyte adhesion in PS formation. Additionally, we developed Sele-targeted siRNA liposome nanoparticles (LNPs) to inhibit monocyte adhesion. Intradermal administration of these LNPs effectively reduced PS formation in both in vivo and in vitro studies.

CONCLUSIONS

This study successfully established a reliable mouse model for PS, highlighting the significant roles of mechanical tension and chronic inflammation in PS formation. We identified Sele as a key therapeutic target and developed Sele-targeted siRNA LNPs, which demonstrated potential as a preventive strategy for PS. These findings provide valuable insights into PS pathogenesis and open new avenues for developing effective treatments for pathological scars.

Characteristics, treatments and outcomes in patients with severe burn wounds; a 10 year cohort study on acute and reconstructive treatment

Reports on treatment characteristics and long term outcomes for severe burns are scarce, while the need to compare outcomes of novel treatment modalities to standard of care is increasing. Our national database on burn treatment enabled analysis of patient as well as treatment characteristics during acute treatment and following reconstructive procedures. Furthermore, outcome data of longitudinal scar assessments were analysed from a single burn centre database. Acute and reconstructive data were analysed for patients admitted to the three Dutch burn centres with total body surface area burned of ≥ 20% TBSA. Long term outcome was analysed from a single centre scar database, both for a period of 2009-2019. Treatment characteristics from 396 surviving acute burn patients were analysed. Surgical treatment was required in 89.6% of these patients and 110 patients (27.8%) needed reconstructive surgery in the years after the burn incident, with a mean of 4.4 reconstructive procedures per patient. Main indications were contractures (70.5%) and arms (45.0%) and head and neck region (41.2%) were most frequently affected. Techniques used for reconstructive corrections were predominantly excision, release and flaps (54.7%), followed by skin transplants (32.4%). Scar quality was significantly worse in patients with more severe burns compared to those with TBSA < 20% during prolonged times. These data provide insight into health care utilization, treatment characteristics and outcomes in severely burned patients. These real-world data can guide future development of improved treatment strategies for at risk patients as well as anatomical locations.

Needle-free jet injector treatment with bleomycin is efficacious in patients with severe keloids: a randomized, double-blind, placebo-controlled trial

BACKGROUND

Severe keloids are difficult to treat. Corticosteroid injections with needles are painful and associated with frequent recurrences. Therefore, more effective, safe and patient-friendly alternative treatments are urgently needed.

OBJECTIVES

To assess the efficacy, tolerability and patient satisfaction of intralesional bleomycin treatment using a needle-free electronic pneumatic jet injector (EPI) in severe keloids.

METHODS

Patients with severe keloids were included in this double-blind, randomized, placebo-controlled trial with split-lesion design. Three EPI treatments with bleomycin or saline were administered every 4 weeks in the intervention and control sides. Outcome measures were change in scar volume assessed by three-dimensional imaging, Patient and Observer Scar Assessment Scale (POSAS), skin perfusion with laser speckle contrast imaging (LSCI), spilled volume, procedure-related pain, adverse events and patient satisfaction.

RESULTS

Fourteen patients (nine female, five male) were included. The estimated mean keloid volume was significantly reduced by 20% after EPI-assisted bleomycin, compared with a slight increase of 3% in the control side (P < 0.01). The estimated mean POSAS patient and observer scores decreased by respectively 28% and 20% (P = 0.03 and P = 0.001). LSCI showed no significant change in perfusion. EPI treatment was preferred over previous needle injections in 85% of patients. The estimated mean spilled volume after EPI was around 50%, and numerical rating scale pain scores were moderate. Adverse events included bruising, hyperpigmentation and transient superficial necrosis.

CONCLUSIONS

A course of three EPI-assisted bleomycin injections is efficacious and well tolerated in severe keloids. Moreover, EPI was preferred by most patients and may serve as a patient-friendly alternative treatment.

miR-3606-3p alleviates skin fibrosis by integratively suppressing the integrin/FAK, p-AKT/p-ERK, and TGF-β signaling cascades

INTRODUCTION

Fibroblast abnormalities are crucial causes of skin fibrosis, including systemic sclerosis (SSc) and keloids. However, their mechanisms, including underlying microRNA regulatory mechanisms, remain elusive.

OBJECTIVES

This study aimed to evaluate the roles, mechanisms, and therapeutic potential of miR-3606-3p in regulating multiple fibroblast abnormalities.

METHODS

The miR-3606-3p levels were evaluated in skin tissues and primary fibroblasts. RNA-seq and luciferase assays were employed to identify miR-3606-3p targets. Collagen contraction, western blotting, in vivo imaging, and real-time cellular analysis were used to assess fibroblast abnormalities. The therapeutic potential of miR-3606-3p was evaluated in mice.

RESULTS

MiR-3606-3p decreased in skin tissues (SSc: Fold Change (FC) =  - 2.95, P = 0.0101; keloid: FC =  - 3.42, P < 0.0001) and primary fibroblasts (SSc: FC =  - 12.74, P = 0.0278; keloid: FC =  - 2.08, P = 0.0021) from skin fibrosis patients, and negatively correlated with disease severity. Mechanistically, miR-3606-3p targeted the 3'-untranslated regions (3'-UTRs) of Integrin αV (ITGAV), GRB2-associated binding protein 1 (GAB1), and transforming growth factor beta receptor 2 (TGFBR2), all of these three targets increased in skin fibrosis. Simultaneously, miR-3606-3p inhibited fibroblast's fibrogenesis, migration, inflammation, and proliferation by inhibiting ITGAV/integrin/FAK, GAB1/p-AKT/p-ERK, and TGFBR2/p-SMAD2/3 signaling. ITGAV-mediated integrin/FAK signaling unidirectionally activated the p-AKT/p-ERK and p-SMAD2/3 pathways. Knockdown of GAB1 and TGFRB2 reduced ITGAV-induced p-AKT/p-ERK and p-SMAD2/3 activities. MiR-3606-3p, si-ITGAV, si-GAB1, and si-TGFBR2 exhibited significant inhibition of fibrogenesis and migration. Inflammation was primarily inhibited by si-ITGAV and si-GAB1, while proliferation was primarily inhibited by si-TGFBR2. Moreover, miR-3606-3p significantly attenuates skin fibrosis in keloid-bearing mice.

CONCLUSIONS

MiR-3606-3p is downregulated in skin fibrosis. Moreover, it negatively correlates with disease severity. Functionally, miR-3606-3p inhibits fibrogenesis, migration, inflammation, and proliferation of fibroblasts. Mechanistically, miR-3606-3p inhibits ITGAV, GAB1, and TGFBR2 by targeting their 3'-UTRs. ITGAV-, GAB1-, and TGFBR2-activated integrin/AKT/ERK/SMAD2/3 signaling induced fibroblast abnormalities. In vivo, miR-3606-3p inhibits skin fibrosis in mice. Therefore, the multi-targeting, multi-phenotypic regulatory properties of miR-3606-3p suggest its potential utility in clinical treatment.

Research Progress of Fibroblasts in Human Diseases

Fibroblasts, which originate from embryonic mesenchymal cells, are the predominant cell type seen in loose connective tissue. As the main components of the internal environment that cells depend on for survival, fibroblasts play an essential role in tissue development, wound healing, and the maintenance of tissue homeostasis. Furthermore, fibroblasts are also involved in several pathological processes, such as fibrosis, cancers, and some inflammatory diseases. In this review, we analyze the latest research progress on fibroblasts, summarize the biological characteristics and physiological functions of fibroblasts, and delve into the role of fibroblasts in disease pathogenesis and explore treatment approaches for fibroblast-related diseases.

Freestanding Hydrogen-Bonded Organic Framework Membrane for Efficient Wound Healing

Hydrogen-bonded organic frameworks (HOFs) are emerging as multifunctional materials with exceptional biocompatibility, abundant active sites, and tunable porosity, which are highly beneficial for advanced wound care. However, a significant challenge involves transforming pristine HOFs powders into lightweight, ultrathin, freestanding membranes compatible with soft biological systems. Herein, the study successfully develops shape-adaptive HOF-based matrix membranes (HMMs) using a polymer-assisted liquid-air interface technique. The HMMs conform seamlessly to tissues of different sizes and shapes, effectively stopping bleeding, and provide high water-vapor permeability. Notably, both in vitro and in vivo studies with mice wound models demonstrated that these tissue-conformable HMMs significantly accelerate wound healing by modulating the inflammatory environment of the injured tissue and promoting rapid re-epithelialization. Furthermore, RNA-seq analysis and mechanistic studies revealed that HMMs effectively reduce inflammation and facilitate the tissue transition from the proliferative stage to the remodeling stage of skin development. This work not only opens up new avenues for advanced wound care materials but also establishes a foundation for hybridizing HOFs with polymers for a wide range of potential applications.

An Update on Molecular Mechanisms of Scarring-A Narrative Review

Fibroblasts, the principal cellular mediators of connective tissue remodeling, play a crucial role in the formation of physiological and pathological scars. Understanding the intricate interplay between fibroblasts and other cellular and molecular components is essential for elucidating the underlying mechanisms driving scar formation. Hypertrophic scars, keloids and atrophic scars arise from dysregulated wound healing processes characterized by persistent inflammation, aberrant collagen deposition, and impaired extracellular matrix remodeling. Fibroblasts play a central role in the pathogenesis of such pathological scars, driving aberrant extracellular matrix remodeling, subsequently contributing to the formation of raised or depressed fibrotic lesions. The investigation of complex interactions between fibroblasts and the microenvironment is crucial for developing targeted therapeutic interventions aimed at modulating fibroblast activity and improving clinical outcomes in patients with pathological scars. Further research into the molecular pathways governing fibroblast behavior and their heterogeneity holds promise for advancing scar management strategies. This narrative review was performed to shed light on the mechanisms behind scar formation, with a special focus on the role of fibroblasts in the formation of different types of scars, providing insights into the pathophysiology of these conditions. Through the analysis of current knowledge, this review seeks to identify the key cellular and molecular mechanisms involved in fibroblast activation, collagen synthesis, and extracellular matrix remodeling in hypertrophic scar, keloid, or atrophic scar formation.

Activatable Near-Infrared Fluorescence Probe for Hypochlorous Acid Detection in Early Diagnosis of Keloids

Keloids represent pathologic conditions characterized by the presence of hyalinized collagen bundles and chronic inflammatory reactions. Recently, increased ROS production and disrupted apoptosis mechanisms in keloids have been reported, although the detailed mechanisms remain unclear. Herein, we developed a specific fluorescence probe, Pro-NBS, to investigate ClO- levels in keloids. The probe demonstrated high specificity for ClO- over other ROS and exhibited a strong linear detection relationship. Based on its performance, we focused on the TGF-β pathway in the development of keloids. ROS upregulation was observed in keloid-derived fibroblasts. Using ClO- as an intrinsic overexpression marker, our probe effectively distinguished between normal fibroblasts and keloid-derived fibroblasts both in vitro and in vivo. Furthermore, Pro-NBS showed potential for monitoring the progression and evaluating the systematic therapy of abnormal scarring or keloids.

Phosphodiesterase 4 is overexpressed in human keloids and its inhibition reduces fibroblast activation and skin fibrosis

There is a pressing medical need for improved treatments in skin fibrosis including keloids and hypertrophic scars (HTS). This study aimed to characterize the role of phosphodiesterase 4 (PDE4), specifically PDE4B in fibrotic skin remodeling in vitro and in vivo. In vitro, effects of PDE4A-D (Roflumilast) or PDE4B (siRNA) inhibition on TGFβ1-induced myofibroblast differentiation and dedifferentiation were studied in normal (NHDF) and keloid (KF) human dermal fibroblasts. In vivo, the role of PDE4 on HOCl-induced skin fibrosis in mice was addressed in preventive and therapeutic protocols. PDE4B (mRNA, protein) was increased in Keloid > HTS compared to healthy skin and in TGFβ-stimulated NHDF and KF. In Keloid > HTS, collagen Iα1, αSMA, TGFβ1 and NOX4 mRNA were all elevated compared to healthy skin confirming skin fibrosis. In vitro, inhibition of PDE4A-D and PDE4B similarly prevented TGFβ1-induced Smad3 and ERK1/2 phosphorylation and myofibroblast differentiation, elevated NOX4 protein and proliferation in NHDF. PDE4A-D inhibition enabled myofibroblast dedifferentiation and curbed TGFβ1-induced reactive oxygen species and fibroblast senescence. In KF PDE4A-D inhibition restrained TGFβ1-induced Smad3 and ERK1/2 phosphorylation, myofibroblast differentiation and senescence. Mechanistically, PDE4A-D inhibition rescued from TGFβ1-induced loss in PPM1A, a Smad3 phosphatase. In vivo, PDE4 inhibition mitigated HOCl-induced skin fibrosis in mice in preventive and therapeutic protocols. The current study provides novel evidence evolving rationale for PDE4 inhibitors in skin fibrosis (including keloids and HTS) and delivered evidence for a functional role of PDE4B in this fibrotic condition.

The Effects of Mesenchymal Stem Cells-Derived Exosomes on Metabolic Reprogramming in Scar Formation and Wound Healing

Pathological scarring results from aberrant cutaneous wound healing due to the overactivation of biological behaviors of human skin fibroblasts, characterized by local inordinate inflammation, excessive extracellular matrix and collagen deposition. Yet, its underlying pathogenesis opinions vary, which could be caused by increased local mechanical tension, enhanced and continuous inflammation, gene mutation, as well as cellular metabolic disorder, etc. Metabolic reprogramming is the process by which the metabolic pattern of cells undergoes a systematic adjustment and transformation to adapt to the changes of the external environment and meet the needs of their growth and differentiation. Therefore, the abnormality of metabolic reprogramming in cells within wounds and scars attaches great importance to scar formation. Mesenchymal stem cells-derived exosomes (MSC-Exo) are the extracellular vesicles that play an important role in tissue repair, cancer treatment as well as immune and metabolic regulation. However, there is not a systematic work to detail the relevant studies. Herein, we gave a comprehensive summary of the existing research on three main metabolisms, including glycometabolism, lipid metabolism and amino acid metabolism, and MSC-Exo regulating metabolic reprogramming in wound healing and scar formation for further research reference.

The effect of inflammatory cytokines on the risk of hypertrophic scar: a mendelian randomization study

Hypertrophic scar (HS) results from burns or trauma, causing aesthetic and functional issues. However, observational studies have linked inflammatory cytokines to HS, but the causal pathways involved are unclear. We aimed to determine how circulating inflammatory cytokines contribute to HS formation. Two-sample Mendelian randomization (MR) was used to identify genetic variants associated with hypertrophic scar in a comprehensive, publicly available genome-wide association study (GWAS) involving 766 patients and 207,482 controls of European descent. Additionally, data on 91 plasma proteins were drawn from a GWAS summary involving 14,824 healthy participants. Causal relationships between exposures and outcomes were investigated primarily using the inverse variance weighted (IVW) method. Furthermore, a suite of sensitivity analyses, including MR‒Egger and weighted median approaches, were concurrently employed to fortify the robustness of the conclusive findings. Finally, reverse MR analysis was conducted to evaluate the plausibility of reverse causation between hypertrophic scar and the cytokines identified in our study. In inflammatory cytokines, there was evidence of inverse associations of osteoprotegerin(OPG) levels(OR = 0.59, 95% CI = 0.41 ∼ 0.85, p = 0.01), and leukemia inhibitory factor(LIF) levels(OR = 0.51, 95% CI = 0.32 ∼ 0.82, p = 0.01) are a nominally negative association with hypertrophic scar risk, while CUB domain-domain-containing protein 1(CDCP1) level(OR = 0.59, 95% CI = 0.41 ∼ 0.85, p = 0.01) glial cell line-derived neurotrophic factor(GDNF) levels(OR = 1.42, 95% CI = 1.03 ∼ 1.96, p = 0.01) and programmed cell death 1 ligand 1(PD-L1) levels(OR = 1.47, 95% CI = 1.92 ∼ 2.11, p = 0.04) showed a positive association with hypertrophic scar risk. These associations were similar in the sensitivity analyses. According to our MR findings, OPG and LIF have a protective effect on hypertrophic scar, while CDCP1, GDNF, and PD-L1 have a risk-increasing effect on Hypertrophic scar. Our study adds to the current knowledge on the role of specific inflammatory biomarker pathways in hypertrophic scar. Further validation is needed to assess the potential of these cytokines as pharmacological or lifestyle targets for hypertrophic scar prevention and treatment.

Human adipose mesenchymal stem cell-derived exosomes alleviate fibrosis by restraining ferroptosis in keloids

Background

Keloid is a fibroproliferative disease with unsatisfactory therapeutic effects and a high recurrence rate. exosomes produced by adipose-derived mesenchymal stem cells (ADSC-Exos) have attracted significant interest due to their ability to treat fibrosis. However, the molecular mechanisms of ADSC-Exos in keloids remain inconclusive.

Objective

Our study revealed the relationship between ferroptosis and fibrosis in keloids. Subsequently, this study aimed to explore further the anti-fibrotic effect of ADSC-Exos on keloids through ferroptosis and the potential underlying mechanisms.

Methods

To investigate the impact of ferroptosis on keloid fibrosis, Erastin and ferrostatin-1 (fer-1) were utilized to treat keloid fibroblast. Keloid keloids treated with Erastin and fer-1 were cocultured with ADSC-Exos to validate the impact of ferroptosis on the effect of ADSC-Exos on keloid anti-ferrotic protein, peroxidase 4 (GPX4) and anti-fibrotic effects in vivo and in vitro by Western blot, as well as variations in iron metabolite expression, malondialdehyde (MDA), liposomal peroxidation (LPO) and glutathione (GSH) were analyzed. The effect of solute carrier family 7-member 11 (SLC7A11) silencing on ADSC-Exo-treated keloid fibroblast was investigated.

Results

Iron metabolite dysregulation was validated in keloids. Fibrosis progression is enhanced by Erastin-induced ferroptosis. The anti-fibrotic effects of ADSC-Exos and fer-1 are related to their ability to prevent iron metabolism. ADSC-Exos effectively suppressed keloid fibrosis progression and increased GSH and GPX4 gene expression. Additionally, the use of Erastin limits the effect of ADSC-Exos in keloids. Furthermore, the effect of ADSC-Exos on keloids was associated with SLC7A11-GPX4 signaling pathway.

Conclusion

We demonstrated a new potential mechanism by which anti-ferroptosis inhibits the progression of keloid fibrosis and identified an ADSC-Exo-based keloid therapeutic strategy. Resisting the occurrence of ferroptosis and the existence of the SLC7A11-GPX4 signaling pathway might serve as a target for ADSC-Exos.

Exosomal miRNA-26b-5p from PRP suppresses NETs by targeting MMP-8 to promote diabetic wound healing

The utilization of platelet-rich plasma (PRP) has exhibited potential as a therapeutic approach for the management of diabetic foot ulcers (DFUs). However, it is currently not well understood how the diabetic environment may influence PRP-derived exosomes (PRP-Exos) and their potential impact on neutrophil extracellular traps (NETs). This study aims to investigate the effects of the diabetic environment on PRP-Exos, their communication with neutrophils, and the subsequent influence on NETs and wound healing. Through bulk-seq and Western blotting, we confirmed the increased expression of MMP-8 in DFUs. Additionally, we discovered that miRNA-26b-5p plays a significant role in the communication between DFUs and PRP-Exos. In our experiments, we found that PRP-Exos miR-26b-5p effectively improved diabetic wound healing by inhibiting NETs. Further tests validated the inhibitory effect of miR-26b-5p on NETs by targeting MMP-8. Both in vitro and in vivo experiments showed that miRNA-26b-5p from PRP-Exos promoted wound healing by reducing neutrophil infiltration through its targeting of MMP-8. This study establishes the importance of miR-26b-5p in the communication between DFUs and PRP-Exos, disrupting NETs formation in diabetic wounds by targeting MMP-8. These findings provide valuable insights for developing novel therapeutic strategies to enhance wound healing in individuals suffering from DFUs.

Graphene Quantum Dots Reduce Hypertrophic Scar by Inducing Myofibroblasts To Be a Quiescent State

Contrary to the initial belief that myofibroblasts are terminally differentiated cells, myofibroblasts have now been widely recognized as an activation state that is reversible. Therefore, strategies targeting myofibroblast to be a quiescent state may be an effective way for antihypertrophic scar therapy. Graphene quantum dots (GQDs), a novel zero-dimensional and carbon-based nanomaterial, have recently garnered significant interest in nanobiomedicine, owing to their excellent biocompatibility, tunable photoluminescence, and superior physiological stability. Although multiple nanoparticles have been used to alleviate hypertrophic scars, a GQD-based therapy has not been reported. Our in vivo studies showed that GQDs exhibited significant antiscar efficacy, with scar appearance improvement, collagen reduction and rearrangement, and inhibition of myofibroblast overproliferation. Further in vitro experiments revealed that GQDs inhibited α-SMA expression, collagen synthesis, and cell proliferation and migration, inducing myofibroblasts to become quiescent fibroblasts. Mechanistic studies have demonstrated that the effect of GQDs on myofibroblast proliferation blocked cell cycle progression by disrupting the cyclin-CDK-E2F axis. This study suggests that GQDs, which promote myofibroblast-to-fibroblast transition, could be a novel antiscar nanomedicine for the treatment of hypertrophic scars and other types of pathological fibrosis.

Liposomes Loaded with 5-Fluorouracil Can Improve the Efficacy in Pathological Scars

Introduction

Pathological scars, such as hypertrophic scars and keloids, are characterized by the proliferation of fibroblasts and the deposition of collagen that often cause pruritus, pain, and disfigurement. Due to their high incidence and deformity, pathological scars have resulted in severe physical and psychological trauma for patients. Intralesional injection of 5-fluorouracil (5-Fu) is a recommended option for treating pathological scars. However, the efficacy of 5-Fu injection was limited and unstable due to limited drug penetration and short retention time.

Methods

Liposomes are promising carriers that have advantages, such as high biocompatibility, controlled release property, and enhanced clinical efficacy. Here, we constructed a transdermal 5-Fu-loaded liposome (5-Fu-Lip) to provide a more effective and safer modality to scar treatment.

Results

Compared to 5-Fu, 5-Fu-Lip showed superior ability in inhibiting primary keloid fibroblasts proliferation, migration, and collagen deposition, and also significantly inhibited human umbilical vein endothelial cells (HUVECs) proliferation and microvessel construction. In vivo experiments demonstrated that 5-Fu-Lip can significantly reduce the severity of hypertrophic scars in a rabbit ear wounding model.

Discussion

5-Fu-Lip provides a promising strategy to improve drug efficacy, which has great potential in the treatment of pathological scars.

The Art of Local Tissue Rearrangements in Burn Reconstruction: Z-Plasty and More

In recent decades, advances in surgical anatomy, burn pathophysiology, surgical techniques, and laser therapy have led to a paradigm shift in how we approach burn scars and contractures. Scar excision and replacement with uninjured tissue, which predominated burn scar treatment for much of the 20th century, is no longer appropriate in many patients. A scar's intrinsic ability to remodel can be induced by reducing tension on the scar using various techniques for local tissue rearrangement. Often in combination with laser therapy, local flaps can optimally camouflage a burn scar with adjacent normal tissue and restore a patient more closely to their preinjury condition.

Effect of black cloth ointment on hypertrophic scar formation: An investigation using integrated network pharmacology and animal assay

BACKGROUND

Hypertrophic scars (HS) are a common disfiguring condition in daily clinical encounters which brings a lot of anxieties and concerns to patients, but the treatment options of HS are limited. Black cloth ointment (BCO), as a cosmetic ointment applicable to facial scars, has shown promising therapeutic effects for facial scarring. However, the molecular mechanisms underlying its therapeutic effects remain unclear.

MATERIAL AND METHODS

Network pharmacology was first applied to analyze the major active components of BCO and the related signaling pathways. Subsequently, rabbit ear scar model was successfully established to determine the pharmacological effects of BCO and its active component β-elemene on HS. Finally, the molecular mechanism of BCO and β-elemene was analyzed by Western blot.

RESULTS

Through the network pharmacology, it showed that β-elemene was the main active ingredient of BCO, and it could significantly improve the pathological structure of HS and reduce collagen deposition. BCO and β-elemene could increase the expression of ER stress-related markers and promote the increase of apoptotic proteins in the Western blot experiment and induce the apoptosis of myofibroblasts.

CONCLUSIONS

Our findings indicate that the material basis for the scar-improving effects of the BCO is β-elemene, and cellular apoptosis is the key mechanism through which the BCO and β-elemene exert their effects.

Microalgae-loaded biocompatible alginate microspheres for tissue repair

Hydrogel-based microcarriers have demonstrated effectiveness in wound repair treatments. The current research focus is creating and optimizing active microcarriers containing natural ingredients capable of conforming to diverse wound shapes and depths. Here, microalgae (MA)-loaded living alginate hydrogel microspheres were successfully fabricated via microfluidic electrospray technology, to enhance the effectiveness of wound healing. The stable living alginate hydrogel microspheres loaded with photoautotrophic MA were formed by cross-linking alginate with calcium ions. The combination of MA-loaded living alginate microspheres ensures high biocompatibility and efficient oxygen release, providing strong support for wound healing. Concurrently, vascular endothelial growth factor (VEGF) has been successfully introduced into the microspheres, further enhancing the comprehensive effectiveness of wound treatment. Covering the rat's wound with these MA-VEGF-loaded alginate microspheres further substantiated their significant role in promoting collagen deposition and vascular generation during the wound closure processes. These results confirm the outstanding value of microalgae-loaded live alginate hydrogel microspheres in wound healing, paving the way for new prospects in future clinical treatment methods.

Injectable hydrogel with doxorubicin-loaded ZIF-8 nanoparticles for tumor postoperative treatments and wound repair

The need for tumor postoperative treatments aimed at recurrence prevention and tissue regeneration have raised wide considerations in the context of the design and functionalization of implants. Herein, an injectable hydrogel system encapsulated with anti-tumor, anti-oxidant dual functional nanoparticles has been developed in order to prevent tumor relapse after surgery and promote wound repair. The utilization of biocompatible gelatin methacryloyl (GelMA) was geared towards localized therapeutic intervention. Zeolitic imidazolate framework-8@ceric oxide (ZIF-8@CeO2, ZC) nanoparticles (NPs) were purposefully devised for their proficiency as reactive oxygen species (ROS) scavengers. Furthermore, injectable GelMA hydrogels loaded with ZC NPs carrying doxorubicin (ZC-DOX@GEL) were tailored as multifunctional postoperative implants, ensuring the efficacious eradication of residual tumor cells and alleviation of oxidative stress. In vitro and in vivo experiments were conducted to substantiate the efficacy in cancer cell elimination and the prevention of tumor recurrence through the synergistic chemotherapy approach employed with ZC-DOX@GEL. The acceleration of tissue regeneration and in vitro ROS scavenging attributes of ZC@GEL were corroborated using rat models of wound healing. The results underscore the potential of the multifaceted hydrogels presented herein for their promising application in tumor postoperative treatments.

The clinical efficacy of single-hole punch excision combined with intralesional steroid injection for nodular keloid treatment: a self-controlled trial

There are many methods to treat keloid, including various excision operations, laser, injection and radiotherapy. However, few studies have explored the effectiveness of single-hole punch excision in keloid treatment. This study aimed to investigate the efficacy and safety of lateral punch excision combined with intralesional steroid injection for keloid treatment through self-control trial. In this self-controlled trial, 50 patients meet the diagnosis of nodular keloid, and try to choose left-right symmetrical control, one skin lesion in the control group (50 skin lesionsin total) and the other in the observation group (50 skin lesions in total).The keloids in the treatment group were initially treated with punch excision combined with intralesional steroid injection, followed by injection treatment alone. Keloids in the control group received intralesional steroid injection alone. The Vancouver Scar Scale (VSS) of the keloid before and after the punch excision was evaluated; the keloid scores at different time points and the number of injection treatments required in both groups were compared, and adverse reactions were observed. The effective rate of the observation group was 86.0%, which was significantly higher than that of the control group (66.0%), and the recurrence rate of 22% was lower than that of the control group (χ2 = 4.141,63417), all of which were statistically significant (all P < 0.05). At the end of treatment, the VSS and total injection times in the observation group were significantly lower than those in the control group (t = 5.900,3.361), with statistical significance (P < 0.01). The combination of single-hole punch excision and intralesional steroid injection is an effective method to treat multiple nodular keloids, shortening the treatment course of tralesional steroid injection without obvious adverse reactions.

Bioactive Dressing: A New Algorithm in Wound Healing

Wound management presents a significant global challenge, necessitating a comprehensive understanding of wound care products and clinical expertise in selecting dressings. Bioactive dressings (BD) represent a diverse category of dressings, capable of influencing wound healing through various mechanisms. These dressings, including honey, hyaluronic acid, collagen, alginates, and polymers enriched with polyhexamethylene biguanide, chitin, and chitosan derivatives, create a conducive environment for healing, promoting moisture balance, pH regulation, oxygen permeability, and fluid management. Interactive dressings further enhance targeted action by serving as substrates for bioactive agents. The continuous evolution of BDs, with new products introduced annually, underscores the need for updated knowledge in wound care. To facilitate dressing selection, a practical algorithm considers wound exudate, infection probability, and bleeding, guiding clinicians through the process. This algorithm aims to optimize wound care by ensuring the appropriate selection of BDs tailored to individual patient needs, ultimately improving outcomes in wound management.

The Role and Prospects of Mesenchymal Stem Cells in Skin Repair and Regeneration

Mesenchymal stem cells (MSCs) have been recognized as a cell therapy with the potential to promote skin healing. MSCs, with their multipotent differentiation ability, can generate various cells related to wound healing, such as dermal fibroblasts (DFs), endothelial cells, and keratinocytes. In addition, MSCs promote neovascularization, cellular regeneration, and tissue healing through mechanisms including paracrine and autocrine signaling. Due to these characteristics, MSCs have been extensively studied in the context of burn healing and chronic wound repair. Furthermore, during the investigation of MSCs, their unique roles in skin aging and scarless healing have also been discovered. In this review, we summarize the mechanisms by which MSCs promote wound healing and discuss the recent findings from preclinical and clinical studies. We also explore strategies to enhance the therapeutic effects of MSCs. Moreover, we discuss the emerging trend of combining MSCs with tissue engineering techniques, leveraging the advantages of MSCs and tissue engineering materials, such as biodegradable scaffolds and hydrogels, to enhance the skin repair capacity of MSCs. Additionally, we highlight the potential of using paracrine and autocrine characteristics of MSCs to explore cell-free therapies as a future direction in stem cell-based treatments, further demonstrating the clinical and regenerative aesthetic applications of MSCs in skin repair and regeneration.