An Updated Review of Hypertrophic Scarring

Decoy oligodeoxynucleotides: A promising therapeutic strategy for inflammatory skin disorders

Chronic inflammatory skin conditions such as psoriasis and atopic dermatitis (AD) impose a significant burden on both the skin and the overall well-being of individuals, leading to a diminished quality of life. Despite the use of conventional treatments like topical steroids, there remains a need for more effective and safer therapeutic options to improve the lives of patients with severe skin conditions. Molecular therapy has emerged as a promising approach to address disorders such as atopic dermatitis, psoriasis, and contact hypersensitivity. One strategy to counteract the disease processes involves targeting the transcriptional process. A novel form of gene therapy utilizes double-stranded oligodeoxynucleotides (ODNs), also known as decoys, that contain cis-elements. By introducing these decoy ODNs through transfection, the cis-trans interactions are disrupted, leading to the inhibition of trans-factors from binding to the intrinsic cis-elements and thus regulating gene expression. In this review, we have summarized studies investigating the therapeutic effects of decoy ODNs on inflammatory skin diseases. Various transcription factors, including NF-kB, STAT6, HIF-1α/STAT5, STAT1, and Smad, have been targeted and inhibited using designed decoy ODNs for the treatment of atopic dermatitis, psoriasis, hypertrophic scarring, and contact hypersensitivity. The findings of these studies confirm the significant potential of the decoy approach in the treatment of inflammatory skin diseases.

CircRNA_SLC8A1 alleviates hypertrophic scar progression by mediating the Nrf2-ARE pathway

BACKGROUND

Hypertrophic scar (HS) is associated with cosmetic defects, mobility, and functional impairments, pruritus, and pain. Previous circRNA microarray analysis identified reduced expression of circRNA_SLC8A1 in HS tissues. Therefore, this study aims to investigate the role of circRNA_SLC8A1 in modulating the abnormal behavior of HS-derived fibroblasts (HSFs) in vitro.

METHODS

RT-qPCR and FISH assays were used to assess the differential expression and localization of circRNA_SLC8A1 in normal and HS tissues. Following modulation of circRNA_SLC8A1 expression, CCK-8, flow cytometry, Transwell, and wound healing assays were employed to evaluate the effects of circRNA_SLC8A1 on the biological behaviors of HSFs. The Starbase database, dual-luciferase reporter assays, and Ago2-RIP assays were utilized to predict and validate the interaction between circRNA_SLC8A1 and downstream miRNAs.

RESULTS

CircRNA_SLC8A1 was found to be downregulated in HS tissues and was primarily localized in the cytoplasm. Overexpression of circRNA_SLC8A1 reduced cell viability, cell invasion, wound healing, and the expression of Vimentin, N-cadherin, Col I, and Col III, while enhancing apoptosis and E-cadherin expression in HSFs. CircRNA_SLC8A1 activates the Nrf2-ARE pathway by competitively binding to miRNA-27a-3p. miRNA-27a-3p and Nrf2 exhibited high and low expression, respectively in HS tissues, with an inverse correlation between their levels. Overexpression of miRNA-27a-3p counteracted the effects of circRNA_SLC8A1 in HSF proliferation, apoptosis, migration, EMT, collagen deposition, and Nrf2-ARE pathway activity.

CONCLUSION

CircRNA_SLC8A1 inhibits the proliferation, migration, EMT, and collagen deposition of HSF through competitive binding with miRNA-27a-3p, thereby activating the Nrf2-ARE pathway. The circRNA_SLC8A1/miRNA-27a-3p/Nrf2-ARE axis may offer a promising molecular target for HS therapy.

Repair and regeneration: ferroptosis in the process of remodeling and fibrosis in impaired organs

As common clinical-pathological processes, wound healing and tissue remodelling following injury or stimulation are essential topics in medical research. Promoting the effective healing of prolonged wounds, improving tissue repair and regeneration, and preventing fibrosis are important and challenging issues in clinical practice. Ferroptosis, which is characterized by iron overload and lipid peroxidation, is a nontraditional form of regulated cell death. Emerging evidence indicates that dysregulated metabolic pathways and impaired iron homeostasis play important roles in various healing and regeneration processes via ferroptosis. Thus, we review the intrinsic mechanisms of tissue repair and remodeling via ferroptosis in different organs and systems under various conditions, including the inflammatory response in skin wounds, remodeling of joints and cartilage, and fibrosis in multiple organs. Additionally, we summarize the common underlying mechanisms, key molecules, and targeted drugs for ferroptosis in repair and regeneration. Finally, we discuss the potential of therapeutic agents, small molecules, and novel materials emerging for targeting ferroptosis to promote wound healing and tissue repair and attenuate fibrosis.

Combined Stromal Vascular Fraction and Fractional CO2 Laser Therapy for Hypertrophic Scar Treatment: A Systematic Review and Meta-Analysis

BACKGROUND

Hypertrophic scars (HTSs) result from aberrant wound healing processes, leading to raised, thickened tissue with functional discomfort and cosmetic concerns. Current treatments, including corticosteroid injections and laser therapy, have limitations. Stromal vascular fraction (SVF) therapy and CO2 laser treatment offer promising avenues, with SVF therapy showing regenerative potential and CO2 laser therapy promoting precise tissue removal and wound healing. This study aims to investigate the combined application of SVF therapy and CO2 laser treatment for HTS, aiming to enhance treatment efficacy, tissue remodeling, and aesthetic outcomes, ultimately improving patient satisfaction in HTS management.

METHOD

PubMed, Scopus, Embase, and Web of Science databases have been searched for relevant studies. The "R" software (version 4.3.1) along with the "tidyverse" and "meta" statistical packages utilized to analyze data related to the efficiency of this combined method. A random-effects model was fitted to the data. For each study, continuous outcomes were pooled by calculating the standardized mean difference, along with their 95% confidence intervals. The assessment of heterogeneity utilized the I2 and chi-squared tests, applying the random effect model.

RESULTS

Six articles fulfilled our inclusion criteria and were included in our review. Results from the pooled analysis of Vancouver Scar Scale (VSS) scores across three included studies indicated a significant impact of the SVF+CO2 method on VSS scores post-treatment (SMD=-3.0144; 95% CI:-4.3706 to -1.6583, p<0.0001). However, analysis of transepidermal water loss levels before and after treatment showed no significant difference (SMD=-2.7603; 95% CI: -6.8729 to 1.3522; p=0.1883). Comparatively, in a pooled analysis of two studies, the combined SVF+CO2 method demonstrated superior efficacy in VSS scores compared to other methods (SMD= -1.3573; 95% CI: -2.2475 to -0.4672, p = 0.0028), with moderate heterogeneity across studies (I^2=23.0%, p = 0.2545).

CONCLUSION

The combined application of SVF and CO2 laser treatment shows significant promise in improving hypertrophic scars' appearance and texture. The SVF+CO2 method demonstrates superior efficacy compared to other modalities, suggesting its potential as a valuable therapeutic approach for hypertrophic scar management.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Losartan in Situ Forming Gel as a New Treatment for Hypertrophic Scars

Hypertrophic scars are defined as visible lesions formed by excessive wound healing that cause cosmetic and, in some cases, functional challenges in patients. This study aimed to assess the efficacy of intralesional injections of losartan-loaded in situ forming gel and compare it with the common treatment (triamcinolone) in preventing scar formation. The formulation was prepared using a thermosensitive PLGA-PEG-PLGA triblock copolymer. Ear scar tissue in rabbits represented the hypertrophic scar, and the animals were treated with three treatments in three groups. Nine weeks following the single treatment, images of the scars were obtained and quantitatively analyzed using ImageJ and light microscopy was used to evaluate the fibroblast cell number, vascularization, inflammation and collagen deposition and fibrosis in H&E-stained sample tissue. According to the results based on the ImageJ and the Vancouver criteria, the losartan in situ forming gel (F-LG) indicated significantly higher improving effects on decreased vascularity and pigmentation in comparison with triamcinolone (F-TA) and placebo as a control (F-Ctl), although the effect F-LG was almost similar to F-TA on pliability and scar height, and they were better than the control. Histological findings showed F-LG and F-TA have less inflammatory and fibroblast cells compared to F-Ctl. Also, results indicated the dermal layers of the F-TA and F-LG groups' scar were thinner, and the deposition of collagens was reduced compared to the control. Consequently, F-LG was found to be an effective treatment in reducing scarring and promoting wound healing.No Level Assigned This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The role of IL-17 and Th17 cells in keloid pathogenesis

Keloids are characterized histologically by excessive fibroblast proliferation and connective tissue deposition, and clinically by scar tissue extending beyond the original site of skin injury. These scars can cause pruritus, pain, physical disfigurement, anxiety, and depression. As a result, keloid patients often have a diminished quality of life with a disproportionate burden on ethnic minorities. Despite advances in understanding keloid pathology, there is no effective Food and Drug Administration (FDA)-approved pharmacotherapy. Recent studies have highlighted the possible pathologic role of T helper (Th)17 cells and interleukin (IL)-17 in keloid formation, as well as their implication in other inflammatory disorders. This systematic review characterizes the role of Th17 cells and IL-17 in keloid pathogenesis, highlighting this pathway as a potential therapeutic target. Adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a comprehensive search on PubMed, Embase, MEDLINE, and Web of Science databases on June 5, 2024. The search included terms related to Th17 cells, IL-17, and keloids. Thirteen studies met the inclusion criteria, comprising basic science and bioinformatic studies focusing on Th17 cells and IL-17. Key findings include increased Th17 cell infiltration and IL-17 expression in keloids, IL-17's role in amplifying the inflammatory and fibrotic response via the promotion of IL-6 expression, and IL-17's involvement in upregulating fibrotic markers via SDF-1 and HIF-1α pathways. IL-17 also activates the transforming growth factor beta (TGF-β)/Smad pathway in keloid fibroblasts. Th17 cells and IL-17 significantly contribute to the inflammatory and fibrotic processes in keloid pathogenesis. Therefore, targeting the IL-17 pathway offers a potential new therapeutic target to improve keloid patients' outcomes. Future research could further elucidate the role of Th17 cells and IL-17 in keloid pathogenesis and assess the safety and efficacy of targeting this pathway in human studies.

Younger age correlates with increased gutter impingement rates after total ankle arthroplasty

BACKGROUND

While total ankle arthroplasty (TAA) has evolved over the years with improved designs and enhanced bony fixation methods, it remains a technically demanding procedure with a risk of early postoperative complications. One of the most common complications associated with TAA is medial and lateral gutter ankle impingement, which can lead to issues such as increased pain and decreased range of motion (ROM). However, there is a paucity of information in the literature discussing the impact of certain risk factors on gutter impingement complications.

METHODS

A retrospective analysis was conducted on a cohort of patients who underwent a TAA at a single institution from 2003 to 2019 with a minimum of 2-year follow-up. Patient were identified as having gutter impingement based on diagnostic imaging and/or clinical examination. Data collection included demographics, implant type, follow-up time, and co-morbidities. Multivariate odds ratios (OR) of experiencing gutter impingement were calculated for perioperative variables.

RESULTS

The study included a total of 908 patients who underwent TAA with a minimum of 2 year follow up and 121 patients (13.3 %) who subsequently experienced gutter impingement. The average follow-up time was 5.84 + /- 3.07 years. There were 178 patients under 55 years old, 495 patients aged 55 to 70, and 235 patients over 70 years old. A higher rate of gutter impingement was observed in patients under 55 years of age compared to those aged 55 to 70 and over 70 (20.8 % vs. 13.5 % vs. 7.2 %; p < 0.01). Multivariable logistic regression revealed that patient age was significantly correlated with gutter impingement following TAA, with an OR of 0.94 (CI: 0.91-0.98; p < 0.01).

CONCLUSION

This study demonstrated increased incidence of gutter impingement in younger patients who underwent TAA. Propensity for scar tissue formation may be higher in this population. Scar tissue deposition following TAA can cause narrowing of the medial and lateral clear spaces, potentially leading to gutter impingement. Additionally, younger patients may have increased activity demands, which subsequently may cause higher rates of symptomatic impingement. As increased impingement after TAA may require the need for additional debridement surgeries, it is important to understand the intricate relationship between age and gutter impingement for managing patient expectations following TAA.

LEVEL OF EVIDENCE

Level III.

Single-cell sequencing analysis and bulk-seq identify IGFBP6 and TNFAIP6 as novel differential diagnosis markers for postburn pathological scarring

BACKGROUND

If not accurately diagnosed and treated, postburn pathological scars, such as keloids and hypertrophic scars, can lead to negative clinical outcomes. However, differential diagnosis at the molecular level for postburn pathological scars remains limited. Using single-cell sequencing analysis, we investigated the genetic nuances of pathological scars at the cellular level. This study aimed to identify molecular diagnostic biomarkers to distinguish between postburn keloids and hypertrophic scars.

METHODS

Single-cell sequencing, differential expression, and weighted co-expression network analyses were performed to identify potential key genes for discriminating between keloids and hypertrophic scars. Postburn clinical samples were collected from our centre to validate the expression levels of the identified key genes.

RESULTS

Single-cell sequencing analysis unveiled 29 and 30 cell clusters in keloids and hypertrophic scars, respectively, predominantly composed of fibroblasts. Bulk differential gene analysis showed 96 highly expressed genes and 69 lowly expressed genes in keloids compared to hypertrophic scars. By incorporating previous research, Gene Set Enrichment Analysis was conducted to select fibroblasts as the focus of research. According to the single-cell data, 301 genes were stably expressed in fibroblasts from both types of pathological scars. Consistently, Weighted Gene Co-expression Network Analysis revealed that the blue module genes were mostly hub genes associated with fibroblasts. After intersecting fibroblast-related genes in single-cell data, Weighted Gene Co-expression Network Analysis-hub module genes, and bulk differential expression genes, insulin-like growth factor binding protein 6 and tumour necrosis factor alpha-induced protein 6 were identified as key genes to distinguish keloids from hypertrophic scars, resulting in diagnostic accuracies of 1.0 and 0.75, respectively. Immunohistochemical Staining and Quantitative Reverse Transcription PCR revealed that the expression levels of tumour necrosis factor alpha induced protein 6 and insulin-like growth factor binding protein 6 were significantly lower in postburn keloids than in hypertrophic scars- CONCLUSIONS: Tumour necrosis factor alpha induced protein 6 and insulin-like growth factor binding protein 6, exhibiting high diagnostic accuracy, provide valuable guidance for the differential diagnosis and treatment of postburn pathological scars.

Integrative Analysis of Lactylome and Proteome of Hypertrophic Scar To Identify Pathways or Proteins Associated with Disease Development

Lactylation (Kla), a recently discovered post-translational modification derived from lactate, plays crucial roles in various cellular processes. However, the specific influence of lactylation on the biological processes underlying hypertrophic scar formation remains unclear. In this study, we present a comprehensive profiling of the lactylome and proteome in both hypertrophic scars and adjacent normal skin tissues. A total of 1023 Kla sites originating from 338 nonhistone proteins were identified based on lactylome analysis. Proteome analysis in hypertrophic scar and adjacent skin samples revealed the identification of 2008 proteins. It is worth noting that Kla exhibits a preference for genes associated with ribosome function as well as glycolysis/gluconeogenesis in both normal skin and hypertrophic scar tissues. Furthermore, the functional enrichment analysis demonstrated that differentially lactyled proteins are primarily involved in proteoglycans, HIF-1, and AMPK signaling pathways. The combined analysis of the lactylome and proteome data highlighted a significant upregulation of 14 lactylation sites in hypertrophic scar tissues. Overall, our investigation unveiled the significant involvement of protein lactylation in the regulation of ribosome function as well as glycolysis/gluconeogenesis, potentially contributing to the formation of hypertrophic scars.

Decellularized Wharton's Jelly and Amniotic Membrane Demonstrate Potential Therapeutic Implants in Tracheal Defects in Rabbits

BACKGROUND

Tracheal grafts have been investigated for over a century, aiming to replace various lesions. However, tracheal reconstruction surgery remains a challenge, primarily due to anatomical considerations, intraoperative airway management, the technical complexity of reconstruction, and the potential postoperative morbidity and mortality. Due to research development, the amniotic membrane (AM) and Wharton's Jelly (WJ) arise as alternatives within the new set of therapeutic alternatives. These structures hold significant therapeutic potential for tracheal defects. This study analyzed the capacity of tracheal tissue regeneration after 60 days of decellularized WJ and AM implantation in rabbits submitted to conventional tracheostomy.

METHODS

An in vivo experimental study was carried out using thirty rabbits separated into three groups (Control, AM, and WJ) (n = 10). The analyses were performed 60 days after surgery through immunohistochemistry.

RESULTS

Different immunomarkers related to scar regeneration, such as aggrecan, TGF-β1, and α-SMA, were analyzed. However, they highlighted no significant difference between the groups. Collagen type I, III, and Aggrecan also showed no significant difference between the groups.

CONCLUSIONS

Both scaffolds appeared to be excellent frameworks for tissue engineering, presenting biocompatibility and a desirable microenvironment for cell survival; however, they did not display histopathological benefits in trachea tissue regeneration.

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.

Insights into the role of adipose-derived stem cells and secretome: potential biology and clinical applications in hypertrophic scarring

Scar tissue is the inevitable result of repairing human skin after it has been subjected to external destructive stimuli. It leads to localized damage to the appearance of the skin, accompanied by symptoms such as itching and pain, which reduces the quality of life of the patient and causes serious medical burdens. With the continuous development of economy and society, there is an increasing demand for beauty. People are looking forward to a safer and more effective method to eliminate pathological scarring. In recent years, adipose-derived stem cells (ADSCs) have received increasing attention from researchers. It can effectively improve pathological scarring by mediating inflammation, regulating fibroblast proliferation and activation, and vascular reconstruction. This review focuses on the pathophysiological mechanisms of hypertrophic scarring, summarizing the therapeutic effects of in vitro, in vivo, and clinical studies on the therapeutic effects of ADSCs in the field of hypertrophic scarring prevention and treatment, the latest application techniques, such as cell-free therapies utilizing ADSCs, and discussing the advantages and limitations of ADSCs. Through this review, we hope to further understand the characterization of ADSC and clarify the effectiveness of its application in hypertrophic scarring treatment, so as to provide clinical guidance.

The Pathophysiology and Management of Pathologic Scarring-a Contemporary Review

Significance: Pathologic scarring occurs secondary to imbalances in the cellular mechanisms of wound healing and affects millions of people annually. This review article aims to provide a concise overview of the pathophysiology and management of pathologic scarring for clinicians and scientists alike. Recent Advances: Contemporary research in the field has identified aberrations in transforming growth factor-β/small mothers against decapentaplegic (TGF-β/SMAD) signaling pathways as key drivers of pathologic scar formation; indeed, this pathway is targeted by many treatment modalities and translational investigations currently underway. Although intralesional injection of corticosteroids has been the gold standard in the treatment of pathologic scarring, studies show greater treatment efficacy with the use of combination injections such as triamcinolone/5-fluorouracil and triamcinolone/botulinum toxin. Adjunctive therapies including ablative fractional carbon dioxide/erbium-doped yttrium aluminum garnet and non-ablative pulsed-dye lasers, microneedling, and carboxytherapy have shown encouraging results in small cohort studies. Translational investigations involving the use of nanogels, RNA interference, and small molecules targeting TGF-β/SMAD pathways are also currently underway and hold promise for the future. Critical Issues: The heterogeneous nature of hypertrophic scars and keloids poses significant challenges in formulating standardized treatment and assessment protocols, thereby limiting the conclusions that can be drawn. Future Directions: Rigorous clinical trials into the individual and synergistic effects of these therapies would be ideal before any definitive conclusions or evidence-based treatment recommendations can be made. Owing to the heterogeneity of the pathology and patient population, well-conducted cohort studies may be the next best option.

HSFAS mediates fibroblast proliferation, migration, trans-differentiation and apoptosis in hypertrophic scars via interacting with ADAMTS8

Hypertrophic scar (HS) is one of the most common sequelae of patients, especially after burns and trauma. The roles of regulatory long noncoding RNAs (lncRNAs) in mediating HS remain underexplored. Human hypertrophic scar-derived fibroblasts (HSFBs) have been shown to exert more potent promoting effects on extracellular matrix (ECM) accumulation than normal skin-derived fibroblasts (NSFBs) and are associated with enhanced HS formation. The purpose of this study is to search for lncRNAs enriched in HSFBs and investigate their roles and mechanisms. LncRNA MSTRG.59347.16 is one of the most highly expressed lncRNAs in HS detected by lncRNA-seq and qRT-PCR and named as hypertrophic scar fibroblast-associated lncRNA (HSFAS). HSFAS overexpression significantly induces fibroblast proliferation, migration, and myofibroblast trans-differentiation and inhibits apoptosis in HSFBs, while knockdown of HSFAS results in augmented apoptosis and attenuated proliferation, migration, and myofibroblast trans-differentiation of HSFBs. Mechanistically, HSFAS suppresses the expression of A disintegrin and metalloproteinase with thrombospondin motifs 8 (ADAMTS8). ADAMTS8 knockdown rescues downregulated HSFAS-mediated fibroblast proliferation, migration, myofibroblast trans-differentiation and apoptosis. Thus, our findings uncover a previously unknown lncRNA-dependent regulatory pathway for fibroblast function. Targeted intervention in the HSFAS-ADAMTS8 pathway is a potential therapy for HS.

Delayed centrifugation weakens the in vitro biological properties of platelet-rich fibrin membranes

OBJECTIVE

To investigate how delayed blood centrifugation affects the composition of the resultant platelet rich fibrin membrane (PRF, a concentrated growth factor preparation) and its biological effects towards gingival fibroblasts.

MATERIALS AND METHODS

Blood samples were collected from 18 healthy individuals and centrifuged immediately (T-0), or after a 1-6-minute delay (T-1-6, respectively), to generate PRF. Each PRF membrane was weighed. T-0 and T-6 membranes were incubated for 48 h in cell culture medium at 37 °C to create PRF "releasates" (soluble factors released from the PRF). Human gingival fibroblasts were incubated for 48 h with or without the releasates, followed by RNA isolation and real-time polymerase chain reaction to measure expression of select genes associated with granulation tissue formation, angiogenesis and wound contraction. Additional T-0 and T-6 membranes were used for visualization of leucocyte nuclei and platelets by immunostaining.

RESULTS

Immediate centrifugation (T-0) resulted in the largest membranes, T-6 membranes being on average 29% smaller. Leucocytes and platelets were significantly more abundant in T-0 than in T-6 samples. Majority of the fibroblast genes studied were consistently either upregulated or downregulated by the T-0 PRF releasates. However, centrifugation after a 6-minute delay significantly weakened the fibroblast responses.

CONCLUSIONS

Delayed centrifugation resulted in smaller PRF membranes with fewer leucocytes and platelets and also significantly reduced on the expression of a set of healing-related gingival fibroblast genes.

CLINICAL RELEVANCE

The higher expression of wound healing-related genes in gingival fibroblasts by the immediately-centrifuged PRF membranes may increase their biological properties in clinical use.

Exosomal microRNA-Based therapies for skin diseases

Based on engineered cell/exosome technology and various skin-related animal models, exosomal microRNA (miRNA)-based therapies derived from natural exosomes have shown good therapeutic effects on nine skin diseases, including full-thickness skin defects, diabetic ulcers, skin burns, hypertrophic scars, psoriasis, systemic sclerosis, atopic dermatitis, skin aging, and hair loss. Comparative experimental research showed that the therapeutic effect of miRNA-overexpressing exosomes was better than that of their natural exosomes. Using a dual-luciferase reporter assay, the targets of all therapeutic miRNAs in skin cells have been screened and confirmed. For these nine types of skin diseases, a total of 11 animal models and 21 exosomal miRNA-based therapies have been developed. This review provides a detailed description of the animal models, miRNA therapies, disease evaluation indicators, and treatment results of exosomal miRNA therapies, with the aim of providing a reference and guidance for future clinical trials. There is currently no literature on the merits or drawbacks of miRNA therapies compared with standard treatments.

Benzbromarone Induces Targeted Degradation of HSP47 Protein and Improves Hypertrophic Scar Formation

Fibrotic diseases are characterized by the abnormal accumulation of collagen in the extracellular matrix, leading to the functional impairment of various organs. In the skin, excessive collagen deposition manifests as hypertrophic scars and keloids, placing a substantial burden on patients and the healthcare system worldwide. HSP47 is essential for proper collagen assembly and contributes to fibrosis. However, identifying clinically applicable HSP47 inhibitors has been a major pharmaceutical challenge. In this study, we identified benzbromarone (BBR) as an HSP47 inhibitor for hypertrophic scarring treatment. BBR inhibited collagen production and secretion in fibroblasts from patients with keloid by binding to HSP47 and inhibiting the interaction between HSP47 and collagen. Interestingly, BBR not only inhibits HSP47 but also acts as a molecular glue degrader that promotes its proteasome-dependent degradation. Through these molecular mechanisms, BBR effectively reduced hypertrophic scarring in mini pigs and rats with burns and/or excisional skin damage. Thus, these findings suggest that BBR can be used to clinically treat hypertrophic scars and, more generally, fibrotic diseases.

Fibroblasts and endothelial cells interplay drives hypertrophic scar formation: Insights from in vitro and in vivo models

Hypertrophic scar formation is influenced by the intricate interplay between fibroblasts and endothelial cells. In this study, we investigated this relationship using in vitro and in vivo models. Clinical observations revealed distinct morphological changes and increased vascularity at pathological scar sites. Further analysis using OCTA, immunohistochemistry, and immunofluorescence confirmed the involvement of angiogenesis in scar formation. Our indirect co-culture systems demonstrated that endothelial cells enhance the proliferation and migration of fibroblasts through the secretion of cytokines including VEGF, PDGF, bFGF, and TGF-β. Additionally, a suspended co-culture multicellular spheroid model revealed molecular-level changes associated with extracellular matrix remodeling, cellular behaviors, inflammatory response, and pro-angiogenic activity. Furthermore, KEGG pathway analysis identified the involvement of TGF-β, IL-17, Wnt, Notch, PI3K-Akt, and MAPK pathways in regulating fibroblasts activity. These findings underscore the critical role of fibroblasts-endothelial cells crosstalk in scar formation and provide potential targets for therapeutic intervention. Understanding the molecular mechanisms underlying this interplay holds promise for the development of innovative approaches to treat tissue injuries and diseases.

Successful Management of Chronic Wounds by an Autophagy-Activating Magnetized Water-Based Gel in Elderly Patients: A Case Series

Chronic wounds pose a significant threat to human health, particularly for the elderly, and require extensive healthcare resources globally. Autophagy, a key molecular player in wound healing, not only offers a defense against infections but also contributes to the deposition of the extracellular matrix during the proliferative phase. Additionally, it promotes the proliferation and differentiation of endothelial cells, fibroblasts, and keratinocytes. We have recently shown that applying magnetized saline water topically can trigger autophagy in intact skin. In this case series, we document the successful management of five non-infected, difficult-to-heal wounds in elderly patients using a topical autophagy-stimulating gel containing 95% magnetized saline water. The treated wounds included pressure ulcers, venous ulcers, and trauma-related injuries that had shown minimal or no improvement with standard wound therapies over a prolonged period. Application of the autophagy-stimulating gel promoted wound healing, as indicated by reduced fibrous and necrotic tissue, granulation tissue formation, re-epithelialization, and partial or complete wound closure. These preliminary case studies suggest that a topical gel containing magnetized saline water, which promotes autophagy, may aid healing of chronic wounds in elderly patients. Further investigation is warranted to explore the potential of this novel approach, as it may offer a valuable addition to the existing arsenal of wound care treatments for the aging population, particularly in addressing difficult-to-heal wounds.

Evidence of Potential Natural Products for the Management of Hypertrophic Scars

Hypertrophic scarring is an aberrant wound-healing response to reestablish dermal integrity after an injury and can cause significant abnormalities in physical, aesthetic, functional, and psychological symptoms, impacting the patient's quality of life. There is currently no gold standard for preventing and treating hypertrophic scars. Therefore, many researchers have attempted to search for antihypertrophic scar agents with greater efficacy and fewer side effects. Natural therapeutics are becoming attractive as potential alternative anti-scarring agents because of their high efficacy, safety, biocompatibility, low cost, and easy accessibility. This review demonstrates various kinds of natural product-based therapeutics, including onion, vitamin E, Gotu kola, green tea, resveratrol, emodin, curcumin, and others, in terms of their mechanisms of action, evidence of efficacy and safety, advantages, and disadvantages when used as anti-scarring agents. We reviewed the literature based on data from in vitro, in vivo, and clinical trials. A total of 23 clinical trials were identified in this review; most clinical trials were ranked as having uncertain results (level of evidence 2b; n = 16). Although these natural products showed beneficial effects in both in vitro and in vivo studies of potential anti-scarring agents, there was limited clinical evidence to support their efficacy due to the limited quality of the studies, with individual flaws including small sample sizes, poor randomization, and blinding, and short follow-up durations. More robust and well-designed clinical trials with large-scale and prolonged follow-up durations are required to clarify the benefits and risks of these agents.

Hypertrophic Scar

Hypertrophic scars frequently develop post-burn, and are characterized by their pruritic, painful, raised, erythematous, dyschromic, and contractile qualities. This article aims to synthesize knowledge on the clinical and molecular development, evolution, management, and measurement of hypertrophic burn scar for both patient and clinician knowledge.

Key Exercise Concepts in the Rehabilitation from Severe Burns

This article presents information on the benefits of exercise in counteracting the detrimental effects of bed rest, and/or severe burns. Exercise is key for maintaining physical function, lean body mass, metabolic recovery, and psychosocial health after major burn injuries. The details of an exercise training program conducted in severely burned persons are presented, as well as information on the importance of proper regulation of body temperature during exercise or physical activity. The sections on exercise and thermoregulation are followed by a section on the role of exercise in scarring and contractures. Finally, gaps in the current knowledge of exercise, thermoregulation, and contractures are presented.

S100 calcium-binding protein A9 promotes skin regeneration through toll-like receptor 4 during tissue expansion

Background

In plastic surgery, tissue expansion is widely used for repairing skin defects. However, low expansion efficiency and skin rupture caused by thin, expanded skin remain significant challenges in promoting skin regeneration during expansion. S100 calcium-binding protein A9 (S100A9) is essential in promoting wound healing; however, its effects on skin regeneration during tissue expansion remain unclear. The aim of the present study was to explore the role of S100A9 in skin regeneration, particularly collagen production to investigate its importance in skin regeneration during tissue expansion.

Methods

The expression and distribution of S100A9 and its receptors-toll-like receptor 4 (TLR-4) and receptor for advanced glycation end products were studied in expanded skin. These characteristics were investigated in skin samples of rats and patients. Moreover, the expression of S100A9 was investigated in stretched keratinocytes in vitro. The effects of S100A9 on the proliferation and migration of skin fibroblasts were also observed. TAK-242 was used to inhibit the binding of S100A9 to TLR-4; the levels of collagen I (COL I), transforming growth factor beta (TGF-β), TLR-4 and phospho-extracellular signal-related kinase 1/2 (p-ERK1/2) in fibroblasts were determined. Furthermore, fibroblasts were co-cultured with stretched S100A9-knockout keratinocytes by siRNA transfection and the levels of COL I, TGF-β, TLR-4 and p-ERK1/2 in fibroblasts were investigated. Additionally, the area of expanded skin, thickness of the dermis, and synthesis of COL I, TGF-β, TLR-4 and p-ERK1/2 were analysed to determine the effects of S100A9 on expanded skin.

Results

Increased expression of S100A9 and TLR-4 was associated with decreased extracellular matrix (ECM) in the expanded dermis. Furthermore, S100A9 facilitated the proliferation and migration of human skin fibroblasts as well as the expression of COL I and TGF-β in fibroblasts via the TLR-4/ERK1/2 pathway. We found that mechanical stretch-induced S100A9 expression and secretion of keratinocytes stimulated COL I, TGF-β, TLR-4 and p-ERK1/2 expression in skin fibroblasts. Recombined S100A9 protein aided expanded skin regeneration and rescued dermal thinning in rats in vivo as well as increasing ECM deposition during expansion.

Conclusions

These findings demonstrate that mechanical stretch promoted expanded skin regeneration by upregulating S100A9 expression. Our study laid the foundation for clinically improving tissue expansion using S100A9.

Intralesional Axitinib Injection Mitigates Hypertrophic Scar by Inhibiting Angiogenesis Pathway: A Preliminary Study in a Rabbit Ear Model

Objective

High levels of VEGF and excessive angiogenesis contribute significantly to hypertrophic scar (HS) formation. Our study aimed to preliminarily investigate the effect of axitinib, a selective VEGF receptor tyrosine kinase inhibitor, on angiogenesis of HS and to explore its possible mechanism in a rabbit ear model.

Methods

Ten male New Zealand white rabbits were used to establish HS models and then randomised to the control and axitinib groups. The scar tissues in the two groups were injected with axitinib or normal saline, and they were evaluated after one month of treatment. Macroscopic scar thickness, vascularity and pliability, as well as histopathological analysis including HE staining and Masson staining and scar elevation index (SEI) between two groups were compared. Immunohistochemical staining of CD31 in two groups was conducted to assess the degree of angiogenesis in HS tissue. The protein expression of protein kinase B (AKT) and ribosomal protein S6 kinase (p70S6K) and their phosphorylation levels in both groups were examined by Western blot analysis.

Results

The macroscopic and histological observation showed intralesional axitinib injection significantly reduced scar thickness, vascularity and pliability of HS in the rabbit ear model. The value of SEI in HE assessment was also significantly declined in the axitinib group. Furthermore, immunohistochemical analysis revealed that axitinib suppressed the expression of CD31 in HS tissue, and the mean IOD for blood vessels was significantly lower in the axitinib-treated group. Additionally, axitinib effectively attenuated the protein expression of p70S6K, p-AKT and p-p70S6K by Western blot analysis.

Conclusion

Our study suggests that intralesional injection of axitinib can effectively attenuate HS by reducing angiogenesis in the rabbit ear model, and this inhibitory effect may be mediated by suppression of AKT/p70S6K signaling pathway. It indicates that axitinib may be a promising option for the treatment of HS in the future.

Paracrine signalling between keratinocytes and SVF cells results in a new secreted cytokine profile during wound closure

Stromal vascular fraction (SVF) cells, and the adipose-derived mesenchymal stem cells they contain, have shown enhanced wound healing in vitro and in vivo, yet their clinical application has been limited. In this regard, understanding the mechanisms that govern SVF-enhanced wound healing would improve their application in the clinic. Here, we show that the SVF cells and keratinocytes engage in a paracrine crosstalk during wound closure, which results in a new cytokine profile that is distinct from the cytokines regularly secreted by either cell type on their own. We identify 11 cytokines, 5 of which are not regularly secreted by the SVF cells, whose expressions are significantly increased during wound closure by the keratinocytes. This new cytokine profile could be used to accelerate wound closure and initiate re-epithelialization without the need to obtain the SVF cells from the patient.

Osteopathic Approach for Keloids and Hypertrophic Scars

The skin is a complex organ, a system that influences and is influenced by the body system, with different skin layers always mechano-biologically active. In the presence of a lesion that damages the dermis, the skin undergoes sensory, morphological, and functional alterations. The subsequent adaptation is the formation of scar tissue, following distinct and overlapping biological phases. For reasons not yet fully elucidated, some healing processes lead to pathological scars, from which symptoms such as pain, itching, and functional limitations are derived. Currently, there is no gold standard treatment that fully meets the needs of different scars and can eliminate any symptoms that the patient suffers. One such treatment is manual medicine, which involves direct manual approaches to the site of injury. Reviewing the phases that allow the skin to be remodeled following an injury, this article reflects on the usefulness of resorting to these procedures, highlighting erroneous concepts on which the manual approach is based, compared to what the current literature highlights the cicatricial processes. Considering pathological scar adaptations, it would be better to follow a gentle manual approach.

Characteristics of Serum Exosomes after Burn Injury and Dermal Fibroblast Regulation by Exosomes In Vitro

(1) Background: Exosomes (EXOs) have been considered a new target thought to be involved in and treat wound healing. More research is needed to fully understand EXO characteristics and the mechanisms of EXO-mediated wound healing, especially wound healing after burn injury. (2) Methods: All EXOs were isolated from 85 serum samples of 29 burn patients and 13 healthy individuals. We characterized the EXOs for morphology and density, serum concentration, protein level, marker expression, size distribution, and cytokine content. After a confirmation of EXO uptake by dermal fibroblasts, we also explored the functional regulation of primary human normal skin and hypertrophic scar fibroblast cell lines by the EXOs in vitro, including cell proliferation and apoptosis. (3) Results: EXOs dynamically changed their morphology, density, size, and cytokine level during wound healing in burn patients, which were correlated with burn severity and the stages of wound healing. EXOs both from burn patients and healthy individuals stimulated dermal fibroblast proliferation and apoptosis. (4) Conclusions: EXO features may be important signals that influence wound healing after burn injury; however, to understand the mechanisms by which EXOs regulates the fibroblasts in healing wounds, further studies will be required.

Exploring the Potential of Ultrasound Therapy to Reduce Skin Scars: An In Vitro Study Using a Multi-Well Device Based on Printable Piezoelectric Transducers

Excessive skin scarring affects over 100 million patients worldwide, with effects ranging from cosmetic to systemic problems, and an effective treatment is yet to be found. Ultrasound-based therapies have been used to treat a variety of skin disorders, but the exact mechanisms behind the observed effects are still unclear. The aim of this work was to demonstrate the potential of ultrasound for the treatment of abnormal scarring by developing a multi-well device based on printable piezoelectric material (PiezoPaint™). First, compatibility with cell cultures was evaluated using measurements of heat shock response and cell viability. Second, the multi-well device was used to treat human fibroblasts with ultrasound and quantify their proliferation, focal adhesions, and extracellular matrix (ECM) production. Ultrasound caused a significant reduction in fibroblast growth and ECM deposition without changes in cell viability or adhesion. The data suggest that these effects were mediated by nonthermal mechanisms. Interestingly, the overall results suggest that ultrasound treatment would a be beneficial therapy for scar reduction. In addition, it is expected that this device will be a useful tool for mapping the effects of ultrasound treatment on cultured cells.