Ursolic acid inhibits human dermal fibroblasts hyperproliferation, migration, and collagen deposition induced by TGF-β via regulating the Smad2/3 pathway

Hypertrophic scar (HS) is a skin condition characterized by excessive fibrosis with disordered collagens from skin fibroblasts, which causes abnormal esthetic and even functional symptoms, thereby affecting millions of people. Ursolic acid (UA) is widely used in skincare and exerts anti-fibrotic effects. The present study aimed to delve into the impact of UA on HS and the mechanism. Fibroblasts (FBs) were incubated with TGF-β to investigate physiological characteristics compared with FBs isolated from normal skin (NSFBs) and hyperplastic scars (HSFBs). TGF-β-incubated FBs were subjected to treatment with UA (0-20 μM). The expressions of Vimentin, α-SMA, Collagen I, and Collagen III were examined using immunofluorescence, RT-qPCR, and western blot. Cell viability, proliferation, apoptosis, migration, and contractility were examined by CCK-8, EdU, Annexin V-FITC/PI, Transwell, and collagen gel contraction assays, respectively. The activation of Smad2/3 signaling was also determined by western blot. The binding sites for UA of TGF-βR1 (ALK5) were predicted by the Autodock tool. Compared with NSFBs, the cell proliferation, migration, and contractility of both HSFBs and TGF-β-incubated FBs were all significantly up-regulated. UA markedly impaired the TGF-β-induced increase in cell proliferation, migration, and contractility, α-SMA, collagen I, and Collagen III expression of FBs. UA significantly inhibited the phosphorylation levels of Smad2/3 in TGF-β-incubated FBs with no influence on TGF-βR1 and TGF-βR2 expressions, which might be because of the binding of UA to the catalytic domain of ALK5 protein. UA attenuated TGF-β1-induced hyperproliferation, migration, and collagen deposition in FBs via regulating the Smad2/3 pathway.

The Intra-rater reliability and validity of ultrasonography in the evaluation of hypertrophic scars caused by burns

PURPOSE

Hypertrophic scars that occur after burns are less flexible and less elastic than normal skin. Objective measurement tools are required to assess hypertrophic scars after thermal injury. Cutometer® MPA 580 has been widely used for evaluating the properties of hypertrophic scars. Ultrasonography can evaluate elasticity, stiffness, and structure of tissues simultaneously using elastography and B-mode. This study aimed to investigate the intra-rater reliability and validity of elastography to visualize hypertrophic scars.

METHODS

Sixteen participants with a total of 96 scars were evaluated. The measurement sequence was elastography, Cutometer®, and elastography every 10 min. We then analyzed the intra-rater reliability using intraclass correlation coefficients (ICC). The results measured using elastography on the hypertrophic scars and surrounding normal skin were compared. The relationships between the elastographic and Cutometer® measurements using the 2-and 8-mm probes were compared.

RESULTS

The intra-rater reliability of elastographic measurements was acceptable for clinical use in terms of strain ratio (SR), shear-wave elastography (SWE), shear-wave speed (SWS), and SWE ratio ( ICC = 0.913, ICC=0.933, ICC = 0.842, and ICC = 0.921). The average SWS and SWE in hypertrophic scars were significantly greater than that for normal skin ( p < 0.001 and p < 0.001). SWE showed correlations with the R0 (r = -0.32, p = 0.002) and R8 (r = -0.30, p = 0.003) measured with the 8-mm probe. The SWE ratio was correlated with the R7 (r = -0.34, p = 0.001) measured with the 2-mm probe. The thickness of hypertrophic scars showed correlations with the R5 (r = 0.33, p < 0.001), R6 (r = 0.44, p < 0.001) and R8 (r = -0.35, p < 0.001) measured with the 8-mm probe. R0-R9 measured with 2-mm Cutometer® probes were not correlated with scar thickness ( r < 0.30, P > 0.05). The total scores of mVSS showed correlations with the R0 (r = 0.35, p < 0.001), R1(r = 0.32., p = 0.001), R3 (r = 0.38, p < 0.001), R4 (r = 0.38, p < 0.001), R8 (r = 0.34, p = 0.001), and R9 (r = 0.34, p = 0.001) measured with the 2-mm probe. R0-R9 measured with 8-mm Cutometer® probes were not correlated with mVSS ( r < 0.30, P > 0.05). The thickness of hypertrophic scars showed correlations with the SWE (r = 0.38, p < 0.001) and SWE ratio (r = 0.35, p < 0.001). Elastographic findings were not correlated with mVSS ( r < 0.30, P > 0.05).

CONCLUSION

In this study, together with the Cutometer®, ultrasound was confirmed as an evaluation tool that can objectively compare and analyze the difference between normal skin and hypertrophic scars.

Keloid disease: Review with clinical atlas. Part I: Definitions, history, epidemiology, clinics and diagnosis

Keloids are chronic progressive dermal pseudo-tumors that can grow considerably in volume and surface area but do not invade other tissues. They are usually triggered by dermal injury or inflammation, but they are not scars in the normal sense of the word, since they enlarge and progress over decades. The phenomenon usually referred to as "hypertrophic scars" represents a kind of keloidal process that does not extend beyond the initial site of injury and spontaneously regresses in 12-24 months. The multiplication of keloids and hypertrophic scars in a single patient is known as keloid disease. Keloid disease is due to a familial predisposition (autosomal dominant) that preferentially affects people of non-European ancestry, especially those of sub-Saharan African descent. Keloid disease has a deep impact on quality of life, not only because of disfiguring lesions, but also because of the frequency of associated intense neurogenic pruritus and pain, as well as recurrent bouts of suppuration. Diagnosis relies primarily on a good knowledge of the clinical characteristics of keloids, thus warranting the inclusion of a clinical atlas in the first part of the review. The second part will deal with the pathology, pathophysiology and treatment of keloid disease.

Occlusion and hydration of scars: moisturizers versus silicone gels

BACKGROUND

The mainstay of non-invasive scar management, consists of pressure therapy with customized pressure garments often combined with inlays, hydration by means of silicones and/or moisturizers as well as UV protection. It is generally accepted that scar dehydration resulting from impaired barrier function of the stratum corneum and expressed by raised trans epidermal water loss (TEWL) values, can lead to increased fibroblast activity and thereby hypertrophic scar formation. However, we have reached no consensus on exactly what optimal scar hydration is nor on barrier function repair: by means of silicone sheets, liquid silicone gels or moisturizers. Occlusive silicone sheets almost completely prevent TEWL and have been shown to be effective. Nevertheless, many important disadvantages due to excessive occlusion such as difficulties in applying the sheets exceeding 10-12 h, pruritus, irritation, and maceration of the skin are limiting factors for its use. To avoid these complications and to facilitate the application, liquid silicone gels were developed. Despite a reduced occlusion, various studies have shown that the effects are comparable to these of the silicone sheets. However, major limiting factors for general use are the long drying time, the shiny aspect after application, and the high cost especially when used for larger scars. Based on excellent clinical results after using three specific moisturizers for scar treatment in our patients, we wanted to investigate whether these moisturizers induce comparable occlusion and hydration compared to both each other and the widely recognized liquid silicone gels. We wanted to provide a more scientific basis for the kind of moisturizers that can be used as a full-fledged and cost-effective alternative to silicone gel.

METHODS

A total of 36 healthy volunteers participated in this study. Increased TEWL was created by inducing superficial abrasions by rigorous (20x) skin stripping with Corneofix® adhesive tape in squares of 4 cm². Three moisturizers and a fluid silicone gel were tested: DermaCress, Alhydran, Lipikar and BAP Scar Care silicone gel respectively. TEWL reducing capacities and both absolute (AAH) and cumulative (CAAH) absolute added hydration were assessed using a Tewameter® TM300 and a Corneometer® CM825 at different time points for up to 4 h after application.

RESULTS

We found an immediate TEWL increase in all the zones that underwent superficial abrasions by stripping. Controls remained stable over time, relative to the ambient condition. The mean percentage reduction (MPR) in TEWL kept increasing over time with Alhydran and DermaCress, reaching a maximum effect 4 h after application. Silicone gel reached maximal MPR almost immediately after application and only declined thereafter. The silicone gel never reached the minimal MPR of Alhydran or DermaCress. Hydration capacity assessed through CAAH as measured by the Corneometer was significantly less with silicone gel compared to the moisturizers. Compared to silicone gel Lipikar provided similar occlusion and the improvement in hydration was highly significant 4 h after application.

CONCLUSION

Based on the results of both our previous research and this study it is clearly demonstrated that the occlusive and hydrative effect of fluid silicone gel is inferior to the moisturizers used in our center. Lipikar hydrates well but is less suitable for scar treatment due to the lack of occlusion. A well-balanced occlusion and hydration, in this study only provided by Alhydran and DermaCress, suggests that moisturizers can be used as a scar hydration therapy that replaces silicone products, is more cost-effective and has a more patient-friendly application.

Peptide deregulated in hypertrophic scar-1 alleviates hypertrophic scar fibrosis by targeting focal adhesion kinase and pyruvate kinase M2 and remodeling the metabolic landscape

Hypertrophic scarring is a fibrotic skin disease characterized by excessive deposition of collagens. Emerging evidence has suggested important roles for peptides in fibrosis-related diseases. Here, we demonstrate that a skin-derived endogenous peptide, peptide deregulated in hypertrophic scar-1 (PDHS1), with the sequence IATTTASAATAAAIGATPRAK, inhibits cell proliferation, promotes apoptosis, decreases the proportion of cells in S phase, and decreases collagen synthesis in hypertrophic scar fibroblasts. Additionally, treatment with PDHPS1 alleviates hypertrophic scarring in a rabbit ear model. PDHPS1 was found to bind to focal adhesion kinase (FAK) and to decrease its activity. PDHPS1 was also shown to bind to pyruvate kinase M2 (PKM2) and to decreased its expression. Smad2 phosphorylation is also inhibited by treatment with PDHPS1. Overexpression of FAK rescues the decreased expression of COL3A1 induced by PDHPS1 treatment. Targeted metabolomics revealed that PDHPS1 reprogramed metabolism that related to amino acid synthesis, leading to decreases of the key glycolysis intermediates glucose-6-phosphate and fructose-6-phosphate. These results demonstrated that the endogenous peptide PDHPS1 alleviates hypertrophic scar fibrosis in vitro and in vivo by targeting FAK and PKM2 and remodeling the metabolic landscape. Overall, treatment with PDHPS1 is a potential therapeutic strategy for hypertrophic scarring.

Salvianolic Acid B Attenuates Hypertrophic Scar Formation In Vivo and In Vitro

BACKGROUND

Hypertrophic scars (HTSs) are a fibroproliferative disorder that occur following skin injuries. Salvianolic acid B (Sal-B) is an extractant from Salvia miltiorrhiza that has been reported to ameliorate fibrosis in multiple organs. However, the antifibrotic effect on HTSs remains unclear. This study aimed to determine the antifibrotic effect of Sal-B in vitro and in vivo.

METHODS

In vitro, hypertrophic scar-derived fibroblasts (HSFs) were isolated from human HTSs and cultured. HSFs were treated with (0, 10, 50, 100 μmol/L) Sal-B. Cell proliferation and migration were evaluated by EdU, wound healing, and transwell assays. The protein and mRNA levels of TGFβI, Smad2, Smad3, α-SMA, COL1, and COL3 were detected by Western blots and real-time PCR. In vivo, tension stretching devices were fixed on incisions for HTS formation. The induced scars were treated with 100 μL of Sal-B/PBS per day according to the concentration of the group and followed up for 7 or 14 days. The scar condition, collagen deposition, and α-SMA expression were analyzed by gross visual examination, H&E, Masson, picrosirius red staining, and immunofluorescence.

RESULTS

In vitro, Sal-B inhibited HSF proliferation, migration, and downregulated the expression of TGFβI, Smad2, Smad3, α-SMA, COL1, and COL3 in HSFs. In vivo, 50 and 100 μmol/L Sal-B significantly reduced scar size in gross and cross-sectional observations, with decreased α-SMA expression and collagen deposition in the tension-induced HTS model.

CONCLUSIONS

Our study demonstrated that Sal-B inhibits HSFs proliferation, migration, fibrotic marker expression and attenuates HTS formation in a tension-induced HTS model in vivo.

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 .

A systematic review of the comparison between needling (RF-needling, meso-needling, and micro-needling) and ablative fractional lasers (CO2, erbium YAG) in the treatment of atrophic and hypertrophic scars

The aim of this study is to compare needling (RF-needling, meso-needling, micro-needling) and ablative fractional lasers (CO2, erbium-YAG) in the treatment of atrophic and hypertrophic scars in a systematic review. The database was searched, and 10 articles were selected that were relevant in terms of content, topic, and purpose and met the inclusion criteria. Of all the articles reviewed in this study, there were 2 randomized split-face trials (20%), 1 controlled nonrandomized trial (10%), 1 controlled randomized phase III clinical trial (10%), 1 prospective trial (10%), 1 prospective nonrandomized open-label trial (10%), and 1 randomized comparative trial (10%), with the type of study not reported in 3 articles. We used Endnote X8 to review the articles and extract data. After review, the studies were analyzed and categorized. No statistically significant difference was found between the two methods, laser and micro-needling, in the treatment of atrophic and hypertrophic scars in 60% of the articles studied, and both showed significant improvement (70% or more improvement to complete response). Significant improvement was noted in 20% of the studies reviewed for the laser and micro-needling treatment methods. The results of this study show that needling and ablative fractional lasers are tolerable and safe procedures with no significant difference in the treatment of skin scars in sixty percent of the studies.

MicroRNA let-7d attenuates hypertrophic scar fibrosis through modulation of iron metabolism by reducing DMT1 expression

Hypertrophic scar is an unavoidable result of wound healing following burns and trauma, which remains a challenging problem for clinicians. Previously, we demonstrated that exosomal microRNAs (miRs) of human amniotic epithelial cells accelerated wound healing and inhibited scar formation. However, the underlying mechanism is still unclear. In this particular study, we found that miR-let-7d reduced collagen deposition, and this was accompanied by decreased level of iron content in myofibroblasts. Importantly, inhibition of miR-let-7d in myofibroblasts accelerated collagen deposition and promoted cell proliferation. In addition, bioinformatics prediction combined with classical dual-luciferase reporter gene assay demonstrated that the cellular iron importer divalent metal transporter 1 (DMT1) was a target gene of miR-let-7d, and the miR-let-7d mimics inhibited the expression of DMT1 in myofibroblasts. Moreover, silencing of DMT1 with small interfering RNA (siRNA) reduced the deposition of extracellular matrix. Consistent with the results in vitro, the miR-let-7d mimics effectively ameliorated hypertrophic scar fibrosis in a rabbit ear hypertrophic scar model. Taken together, our results indicated for the first time that miR-let-7d attenuated hypertrophic scar fibrosis through modulation of iron metabolism by reducing iron uptake through DMT1, which may provide a novel therapeutic strategy for hypertrophic scar.

Efficacy and Safety of Verapamil Versus Triamcinolone Acetonide in Treating Keloids and Hypertrophic Scars: A Systematic Review and Meta-Analysis

BACKGROUND

Keloids and hypertrophic scars can affect the appearance and normal function of patients, and may severely affect patients' physical and mental health. Many methods have been used for the treatment of keloids and hypertrophic scars, there is no standardized method so far. The aim of this study was to compare the efficacy and safety of verapamil and triamcinolone acetonide (TAC) in treating keloids and hypertrophic scars.

METHODS

All studies from their inception date up to August 2022 were searched using four databases (PubMed, Cochrane Library, MEDLINE, and EMBASE). The weighted mean differences and the risk ratio were calculated for comparing continuous variables and dichotomous variables, respectively.

RESULTS

A total of nine randomized controlled trials involving 567 patients were identified. This meta-analysis indicated that TAC group showed significantly better effects compared with verapamil group in the reduction of height at 3 and 9 weeks, pliability at 3, 9, and 18 weeks, vascularity at 3, 6, 9, 12, 18, and 24 weeks, whereas verapamil group showed significantly better effects compared with TAC group in the reduction of pliability at 21 and 24 weeks. Verapamil group showed a significantly lower incidence of skin atrophy, telangiectasia, and hypopigmentation compared with TAC group. However, the incidence of burning sensation in verapamil group was higher than that in TAC group.

CONCLUSION

Concerning the treatment of keloids and hypertrophic scars, TAC was more effective than verapamil for improving vascularity; TAC was superior to verapamil in improving height within 9 weeks of treatment; TAC produced superior result for improving pliability within 18 weeks of treatment, whereas verapamil produced superior result between 18 and 24 weeks of treatment. Verapamil had fewer adverse events than TAC and can be used as a safer alternative for the treatment of keloids and hypertrophic scars.

LEVEL OF EVIDENCE II

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 .

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

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

Angiogenesis modulation-mediated inhibitory effects of tacrolimus on hypertrophic scar formation

Hypertrophic scar (HS) is a fibroproliferative disorder that causes cosmetic as well as functional problems; however, to our knowledge, there is no satisfactory treatment for HS to date. Previous studies have indicated that angiogenesis plays a crucial role in HS formation; therefore, anti-angiogenetic therapies are considered effective in improving HS. Although tacrolimus (TAC) has been proven effective in preventing HS formation in vivo and in vitro, its underlying mechanism remains controversial and ambiguous. Because of its anti-angiogenic effects in other diseases, we aimed to determine whether TAC reduces HS by suppressing angiogenesis. Using a rabbit ear HS model that we developed, HS was treated once a week with normal saline, dimethyl sulfoxide, or TAC for 3 weeks. Histological evaluation indicated that TAC significantly reduced collagen deposition and microvessel density in scar tissues. Moreover, immunofluorescence staining for CD31 and vascular endothelial growth factor (VEGF)-A revealed that TAC significantly inhibited HS angiogenesis. In vitro analysis showed that TAC inhibited endothelial cell migration and tubulogenesis as well as the viability and proliferation of human umbilical vascular endothelial cells (HUVECs) and HS fibroblasts (HSFBs). Furthermore, TAC significantly downregulated the expression of the human angiogenetic factors VEGF-A, FGF-2, PDGF-β, and TGF-β1 in HUVECs and HSFBs. Additionally, TAC-mediated inhibition of angiogenesis decreased the gene expression of crucial fibrotic markers, including α- smooth muscle actin and collagens 1 and 3, in HSFBs. This is the first study to demonstrate the inhibitory effects of TAC on HS formation mediated by a mechanism involving the suppression of scar angiogenesis.

Comparing the Efficacy of Multiple Drugs Injection for the Treatment of Hypertrophic Scars and Keloid: A Network Meta-Analysis

BACKGROUND

There is no consensus regarding the choice of injected drugs for pathological scars. Although the clinical efficacy of different drug treatments was shown in many randomized controlled trials, the efficacies of many drugs are inconsistent. Therefore, this study aimed to determine how different effective drugs are for treating pathological scars. It is anticipated that the study findings may serve as guidelines for plastic surgeons.

METHODS

Relevant literature was extracted from the following databases Cochrane Library, Embase, PubMed, Web of Science, CNKI, Weipu, and Wanfang until June 2022, such as randomized clinical trials (RCTs) evaluating different injected drugs for the treatment of pathological scars, including BTA, TAC, 5-Fu, VER, and BLE.

RESULTS

This network meta-analysis of 1539 patients from 23 articles revealed that the most effective treatment for a pathological scar was TAC + BTA. The effective rate of TAC + BTA combination therapy was significantly different from that of the BTA, TAC, 5-Fu, VER, and BLM monotherapies. TAC+5-FU was more effective than TAC, 5-FU, VER, or BLM alone, and BTA was more effective than both TAC and 5-Fu. The effectiveness of VER and BLM was the same, but both were better than TAC and 5-Fu. No big differences were found between any of the other local injection therapies.

CONCLUSIONS

According to this network meta-analysis, a combination of keloid and hypertrophic scar injection treatment is recommended, especially BTA+TAC. However, this network meta-analysis has some limitations and must be further verified by larger samples and higher quality RCTs.

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.

Efficacy of Dry Needling in Treating Scars following Total Hip Arthroplasty: A Case Report

Background: In this case report of a 31-year-old female, we describe the effects of dry needling on scar tissue following total hip arthroplasty. Case report: A 31-year-old woman underwent an elective bilateral total hip replacement due to a motor vehicle accident. Based on physical examination, the patient had burning pain at the incision site at the time of menstruation and limited hip range of motion worse on the right side. The treatment program consisted of six sessions of dry needling over a three-week period alongside infrared radiation for 20 minutes during each session. The needles were spaced along the entire length of the scar tissue and rotation was performed back and forth across the scar region to release the adhesion between the scar line and the underlying tissue, focusing more on the painful-to-touch spots and adhesive points. Following the completion of the dry needling treatments hip range of motion and the patient's functional outcome improved. Dry needling may be an effective and rapid treatment for scar tissue adhesion after surgical procedures. High-quality randomized-controlled studies are needed to verify the efficacy of this method.

Concentration-Dependent Inhibition of Hypertrophic Scar Formation by Botulinum Toxin Type A in a Rabbit Ear Model

BACKGROUND

Hypertrophic scar (HS), as a disappointing result of wound healing, adversely affects the patient, both physically and psychologically. Botulinum toxin type A (BTXA) has been revealed to prevent and improve HS. We conducted this study to assess the effect of different BTXA concentrations on inhibiting HS in a rabbit ear model.

METHODS

Eight healthy New Zealand long-eared rabbits were included in the experiment for modeling. Four wounds of 1 cm in diameter were created on both ears, which separately received an injection of a given BTXA concentration immediately after surgery. On postoperative days 40, scar tissue was obtained and subjected to hematoxylin and eosin (HE) staining for the hypertrophic index (HI) and immunohistochemical staining for CD31, Ki67, and transforming growth factor-beta 1 (TGF-β1) expression. The HI was assessed for scar proliferation, and CD31 and Ki67 expression were used to assess the effect of BTXA on angiogenesis and fibroblast proliferation, respectively.

RESULTS

All rabbits healed well without infection or mortality. From the HE staining, the HI showed a significant decrease with increasing BTXA concentration (p < 0.05). BTXA also inhibited angiogenesis and TGF-β1 expression in a concentration-dependent manner, with significant differences between the groups (p < 0.05). BTXA inhibited fibroblast proliferation with increasing BTXA concentration. However, there was no significant difference between the 0.5 U/0.1 ml and 0 U/0.1 ml groups (p > 0.05).

CONCLUSION

Immediate postoperative BTXA injection inhibited angiogenesis, fibroblast proliferation, and TGF-β1 expression in a concentration-dependent manner, thus suppressing HS formation in rabbit ears.

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 https://www.springer.com/journal/00266 .

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Photobiomodulation therapy with an 830-nm light-emitting diode for the prevention of thyroidectomy scars: a randomized, double-blind, sham device-controlled clinical trial

This randomized, double-blind, and sham device-controlled trial aimed to evaluate the efficacy and safety of home-based photobiomodulation therapy using an 830-nm light-emitting diode (LED)-based device for the prevention of and pain relief from thyroidectomy scars. Participants were randomized to receive photobiomodulation therapy using an LED device or a sham device without an LED from 1 week postoperatively for 4 weeks. Scars were assessed using satisfaction scores, the numeric rating scale (NRS) score for pain, Global Assessment Scale (GAS), and Vancouver Scar Scale (VSS) scores. The scars were also assessed using a three-dimensional (3D) skin imaging device to detect color, height, pigmentation, and vascularity. Assessments were performed at the 1-, 3-, and 6-month follow-ups. Forty-three patients completed this trial with 21 patients in the treatment group and 22 patients in the control group. The treatment group showed significantly higher patient satisfaction and GAS scores and lower NRS and VSS scores than the control group at 6 months. Improvements in color variation, height, pigmentation, and vascularity at 6 months were greater in the treatment group than in the control group, although the differences were not significant. In conclusion, early application of 830-nm LED-based photobiomodulation treatment significantly prevents hypertrophic scar formation and reduces postoperative pain without noticeable adverse effects.

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

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

Decorin mediated biomimetic PCL-gelatin nano-framework to impede scarring

Scars occur as a result of fibrosis after tissue damage or surgery and reports suggest that excessive Transforming growth factor-β (TGF-β) activity during the process of wound healing leads to progressive fibrosis. Decorin is an extracellular matrix (ECM) protein which regulates collagen fibrillogenesis. However, targeted delivery and effective protein therapy remains a challenge owing to degradation byproteases. Hence, we aimed to deliver Decorin in a sustainable mode for the reduction of TGF-β levels and subsequent scar formation. Herein, we have fabricated PCL-Gelatin bio-mimetic scaffolds to optimize the bio-activity and provide localized delivery of recombinant Decorin. The degradation and drug release patterns reveals that this biomaterial is biodegradable and offers sustained release of the recombinant Decorin. Decorin loaded nanofiber displayed lower adhesion and proliferation rates in in-vitro conditions. Moreover, Decorin loaded scaffolds demonstrated morphological changes in cells, specifically targeting the myofibroblast. The expression of TGF-β was also scrutinized to understand the effect of Decorin loaded nanofibers. Besides, in the in-vitro fibrotic model, Decorin loaded nanofibers efficiently reduced the expression of ECM related proteins. Therefore, we report the sustained delivery of the recombinant Decorin from nanofiber dressing to potentially obstruct scar formation during the process of wound healing.

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

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

Three-dimensional printing bilayer membranous nanofiber scaffold for inhibiting scar hyperplasia of skin

Hypertrophic scar (HS) is the manifestation of pathological wound healing, which affects the beauty of patients, and even affects the normal physical functions of patients. We aimed to develop a 3D printing layer membranous nanofiber scaffold similar to skin structure. Among them, poly (lactic-co-glycolic acid) copolymer (PLGA) nanofibers were used as the "epidermis" layer above, and a decellular dermis matrix (dECM) nanofiber scaffold was used as the "dermis" layer below. In vitro, experimental results showed that PLGA and dECM nanofiber scaffolds had good biocompatibility. In vivo experiments showed that BLM nanofiber scaffolds could inhibit collagen fiber deposition and angiogenesis, to inhibit the formation of hypertrophic scars. This study shows a simple and effective method for preventing and inhibiting the formation of hypertrophic scars.

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

Background

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

Methods

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

Results

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

Conclusions

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

Regenerative effect of combined laser and human stem cell-conditioned medium therapy on hypertrophic burn scar

PURPOSE

This study aimed to determine the effect of combined treatment with non-ablative laser and human stem cell-conditioned medium (HSCM) on tissue regeneration after burn-induced hypertrophic scar (HTS) formation.

METHODS

Fourteen patients with HTSs on both sides of the same body part were subjected to three sessions of non-ablative laser treatment, with an interval of four weeks between each treatment. Following laser treatment, HSCM and normal saline were applied to the HTSs of the right (experimental) and left side (control), respectively. Over the next 6 days, HSCM and moisturizer were applied to experimental scars, while only moisturizer was applied to control scars. Skin characteristics were evaluated before laser treatment and on the seventh day after the third laser treatment.

RESULTS

No significant intergroup differences were noted in the initial evaluation (P > 0.05). We found significant differences between the pre- and post-treatment measurements of erythema (P < 0.001), trans-epidermal water loss (TEWL; P < 0.001), and Cutometer® parameters (all parameters; P <0^.05) of experimental scars. Control scars also showed significant differences between pre- and post-treatment measurements of thickness (P = 0.01), erythema (P < 0.001), TEWL (P < 0.001), and Cutometer® parameters (all parameters; P < 0.05). Changes (pre- to post-treatment) in scar thickness between the experimental (-0.003 ± 0.09) and control scars (0.04 ± 0.12) were significant (P = 0.01).

CONCLUSION

These results suggest that HSCM has a positive effect on short-term results when applied after laser treatment of hypertrophic scars.

The use of fluid silicone gels in the prevention and treatment of hypertrophic scars: a systematic review and meta-analysis

BACKGROUND

Silicone products, either as a sheet or in fluid form, are universally considered as the first line therapy in the prevention and treatment of hypertrophic scars and keloids. However, the study results have been questioned by different authors and there has never been a large systematic synopsis published on the efficacy of fluid silicone gels. This systematic review aims to elucidate the available evidence of the results obtained by fluid silicone gels and present a complete and comprehensive overview of the available literature as well as a meta-analysis of the pooled data.

METHODS

A systematic search for articles concerning the use of silicone gel in the treatment and prevention of scars was performed on 3 different databases (Pubmed, Embase and Cochrane library) according to the PRISMA statement. Only RCT's were included. Qualitative assessment was done by 2 separate reviewers using the Cochrane risk of bias (RoB 2) assessment tool. Revman 5.4.1 software was used for meta-analysis.

RESULTS

The search yielded 507 articles. Two articles were identified through other sources. After deduplication and removal of ineligible records, 340 records were screened on title and abstract. Full text screening was done for 23 articles and ultimately 18 articles were included. A meta-analysis comparing fluid silicone gel to no treatment or placebo gels was conducted.

CONCLUSION

Studies on the effects of liquid silicone gels on hypertrophic scars are numerous and this systematic review shows that the use of liquid silicone gels is associated with both a prophylactic and a curative effect on scars. However, a considerable amount of the available 'high evidence' trials are at a high risk for bias and it is uncertain whether or not the effects of silicone gels are comparable to silicone sheets and if the additional components present in many silicone gels are partially responsible for their scar improving capacity.

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

BACKGROUND AND OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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