Scars

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.

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.

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.

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.

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.

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.

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.

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.

Myofibroblasts reside in the middle dermis of the keloids but do not predict the response to injection therapies: a double-blinded, randomized, controlled trial

Introduction

Keloids form as a pathological response to skin wound healing, and their etiopathology is poorly understood. Myofibroblasts, which are cells transformed from normal fibroblasts, are believed to contribute to pathological scar formation in wounds.

Methods

We carried out a double-blinded randomized controlled trial (RCT) comparing the efficacy of intralesional 5-fluorouracil (5-FU) and triamcinolone (TAC) injections in treating keloids. A total of 43 patients with 50 keloids were treated with either intralesional TAC or 5-FU injections, and their clinical response was evaluated. Biopsies were collected before, during, and after injection therapy from the active border of a keloid. To understand the role of myofibroblasts in keloids, we conducted an immunohistochemical analysis to identify myofibroblasts [α-smooth muscle actin (αSMA)] from the biopsies. We first defined the three histologically distinct regions-superficial, middle, and deep dermis-in each keloid.

Results

We then demonstrated that myofibroblasts almost exclusively exist in the middle dermis of the keloids as 80% of the cells in the middle dermis were αSMA positive. However, both the percentage of myofibroblasts as well as the area covered by them was substantially lower in the superficial and deep dermis than in the middle dermis of the keloids. Myofibroblasts do not predict the clinical response to intralesional injection therapies. There is no difference in the myofibroblast numbers in keloids or in the induced change in myofibroblasts between the responders and non-responders after treatment.

Discussion

This study demonstrates that myofibroblasts reside almost exclusively in the middle dermis layer of the keloids, but their numbers do not predict the clinical response to intralesional injection therapies in the RCT.

Insights into How Plant-Derived Extracts and Compounds Can Help in the Prevention and Treatment of Keloid Disease: Established and Emerging Therapeutic Targets

Keloid is a disease in which fibroblasts abnormally proliferate and synthesize excessive amounts of extracellular matrix, including collagen and fibronectin, during the healing process of skin wounds, causing larger scars that exceed the boundaries of the original wound. Currently, surgical excision, cryotherapy, radiation, laser treatment, photodynamic therapy, pressure therapy, silicone gel sheeting, and pharmacotherapy are used alone or in combinations to treat this disease, but the outcomes are usually unsatisfactory. The purpose of this review is to examine whether natural products can help treat keloid disease. I introduce well-established therapeutic targets for this disease and various other emerging therapeutic targets that have been proposed based on the phenotypic difference between keloid-derived fibroblasts (KFs) and normal epidermal fibroblasts (NFs). We then present recent studies on the biological effects of various plant-derived extracts and compounds on KFs and NFs. Associated ex vivo, in vivo, and clinical studies are also presented. Finally, we discuss the mechanisms of action of the plant-derived extracts and compounds, the pros and cons, and the future tasks for natural product-based therapy for keloid disease, as compared with existing other therapies. Extracts of Astragalus membranaceus, Salvia miltiorrhiza, Aneilema keisak, Galla Chinensis, Lycium chinense, Physalis angulate, Allium sepa, and Camellia sinensis appear to modulate cell proliferation, migration, and/or extracellular matrix (ECM) production in KFs, supporting their therapeutic potential. Various phenolic compounds, terpenoids, alkaloids, and other plant-derived compounds could modulate different cell signaling pathways associated with the pathogenesis of keloids. For now, many studies are limited to in vitro experiments; additional research and development are needed to proceed to clinical trials. Many emerging therapeutic targets could accelerate the discovery of plant-derived substances for the prevention and treatment of keloid disease. I hope that this review will bridge past, present, and future research on this subject and provide insight into new therapeutic targets and pharmaceuticals, aiming for effective keloid treatment.