The Immunomodulatory Effects of Mesenchymal Stem Cells in Prevention or Treatment of Excessive Scars

Immediate SVF-Gel Injection Reduced Incision Scar Formation: A Prospective, Double-Blind, Randomized, Self-control Trial

BACKGROUND

Skin incision scars are cosmetically displeasing; the effects of current treatments are limited, and new methods to reduce scar formation need to be found.

OBJECTIVE

We sought to determine whether immediate postoperative injection of stromal vascular fraction gel (SVF-gel) could reduce scar formation at skin incision sites.

METHODS

A prospective, randomized, double-blind, self-controlled trial was conducted in patients who underwent breast reduction. SVF-gel was intradermally injected into the surgical incision on one randomly selected side, with the other side receiving saline as a control. At the 6-month follow-up, the incision scars were evaluated using the Vancouver scar scale (VSS) and visual analog scale (VAS). Antera 3D camera was used for objective evaluation.

RESULTS

The VSS score and VAS score were significantly different between the SVF-gel-treated side (3.80 ± 1.37, 3.37±1.25) and the control side (5.25 ± 1.18, 4.94 ± 1.28). Moreover, the SVF-gel-treated side showed statistically significant improvements in scar appearance, based on evidences from Antera 3D camera.

LIMITATIONS

This was a single-center, single-race, and single-gender study. Furthermore, the results were available only for the 6-month interim follow-up period.

CONCLUSION

Postoperative immediate SVF-gel injection in surgical incisions can reduce scar formation, and exert a preventive effect on scars.

LEVEL OF EVIDENCE I

Evidence obtained from at least one properly designed randomized controlled trial. 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 .

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.

Scarring and Skin Fibrosis Reversal with Regenerative Surgery and Stem Cell Therapy

Skin scarring and fibrosis affect millions of people worldwide, representing a serious clinical problem causing physical and psychological challenges for patients. Stem cell therapy and regenerative surgery represent a new area of treatment focused on promoting the body's natural ability to repair damaged tissue. Adipose-derived stem cells (ASCs) represent an optimal choice for practical regenerative medicine due to their abundance, autologous tissue origin, non-immunogenicity, and ease of access with minimal morbidity for patients. This review of the literature explores the current body of evidence around the use of ASCs-based regenerative strategies for the treatment of scarring and skin fibrosis, exploring the different surgical approaches and their application in multiple fibrotic skin conditions. Human, animal, and in vitro studies demonstrate that ASCs present potentialities in modifying scar tissue and fibrosis by suppressing extracellular matrix (ECM) synthesis and promoting the degradation of their constituents. Through softening skin fibrosis, function and overall quality of life may be considerably enhanced in different patient cohorts presenting with scar-related symptoms. The use of stem cell therapies for skin scar repair and regeneration represents a paradigm shift, offering potential alternative therapeutic avenues for fibrosis, a condition that currently lacks a cure.

TC14012 enhances the anti-fibrosis effects of UC-MSCs on the liver by reducing collagen accumulation and ameliorating inflammation

BACKGROUND

Mesenchymal stem cells (MSCs) are attracting attention as a promising cell-based therapy for the treatment of liver fibrosis or cirrhosis. However, the strategies and potential mechanisms of MSCs therapy need further investigation. The CXCL12/CXCR4/CXCR7 chemokine axis is well known to regulate cell migration and is involved in the regulation of liver fibrosis. This study aims to treat MSCs with a CXCR7-specific agonist to evaluate its therapeutic effects on hepatic fibrosis and potential mechanisms.

METHODS

TC14012, a potent agonist of CXCR7, has been used to pretreat human umbilical cord-derived MSCs (UC-MSCs) and assess its effect on proliferation, apoptosis, migration, immunoregulation, and gene regulatory network. Then, CCl4-induced liver fibrosis mice models were used to evaluate the therapeutic effect and mechanism of TC14012-treated UC-MSCs for treating hepatic fibrosis.

RESULTS

TC14012 increased CXCR7 expression in UC-MSCs. Notably, co-culture of liver sinusoidal endothelial cells (LSEC) with TC14012-pretreated UC-MSCs increased CXCR7 expression in LSEC. Additionally, TC14012 promoted cell migration and mediated the immunoregulation of UC-MSCs. Compared to UC-MSCs without TC14012 pretreatment, UC-MSCs treated with TC14012 ameliorated live fibrosis by restoring CXCR7 expression, reducing collagen fibril accumulation, inhibiting hepatic stellate cells activation, and attenuating the inflammatory response.

CONCLUSION

This study suggests that TC14012 pretreatment can enhance the therapeutic effects of UC-MSCs on liver fibrosis, mainly by promoting the migration and immunoregulation of MSCs.

Biodistribution-based Administration of cGMP-compliant Human Umbilical Cord Mesenchymal Stem Cells Affects the Therapeutic Effect of Wound Healing

BACKGROUND

Although mesenchymal stem cells (MSCs) are used as therapeutic agents for skin injury therapy, few studies have reported the effects of dosing duration and delivery frequency on wound healing. In addition, before the clinical application of MSCs, it is important to assess whether their usage might influence tumor occurrence.

METHODS

We described the metabolic patterns of subcutaneous injection of hUC-MSCs using fluorescence tracing and qPCR methods and applied them to the development of drug delivery strategies for promoting wound healing.

RESULTS

(i) We developed cGMP-compliant hUC-MSC products with critical quality control points for wound healing; (ii) The products did not possess any tumorigenic or tumor-promoting/inhibiting ability in vivo; (iii) Fluorescence tracing and qPCR analyses showed that the subcutaneous application of hUC-MSCs did not result in safety-relevant biodistribution or ectopic migration; (iv) Reinjecting hUC-MSCs after significant consumption significantly improved reepithelialization and dermal regeneration.

CONCLUSIONS

Our findings provided a reference for controlling the quality of MSC products used for wound healing and highlighted the importance of delivery time and frequency for designing in vivo therapeutic studies.

Therapeutic potential of stem cells in regeneration of liver in chronic liver diseases: Current perspectives and future challenges

The deposition of extracellular matrix and hyperplasia of connective tissue characterizes chronic liver disease called hepatic fibrosis. Progression of hepatic fibrosis may lead to hepatocellular carcinoma. At this stage, only liver transplantation is a viable option. However, the number of possible liver donors is less than the number of patients needing transplantation. Consequently, alternative cell therapies based on non-stem cells (e.g., fibroblasts, chondrocytes, keratinocytes, and hepatocytes) therapy may be able to postpone hepatic disease, but they are often ineffective. Thus, novel stem cell-based therapeutics might be potentially important cutting-edge approaches for treating liver diseases and reducing patient' suffering. Several signaling pathways provide targets for stem cell interventions. These include pathways such as TGF-β, STAT3/BCL-2, NADPH oxidase, Raf/MEK/ERK, Notch, and Wnt/β-catenin. Moreover, mesenchymal stem cells (MSCs) stimulate interleukin (IL)-10, which inhibits T-cells and converts M1 macrophages into M2 macrophages, producing an anti-inflammatory environment. Furthermore, it inhibits the action of CD4+ and CD8+ T cells and reduces the activity of TNF-α and interferon cytokines by enhancing IL-4 synthesis. Consequently, the immunomodulatory and anti-inflammatory capabilities of MSCs make them an attractive therapeutic approach. Importantly, MSCs can inhibit the activation of hepatic stellate cells, causing their apoptosis and subsequent promotion of hepatocyte proliferation, thereby replacing dead hepatocytes and reducing liver fibrosis. This review discusses the multidimensional therapeutic role of stem cells as cell-based therapeutics in liver fibrosis.

An Overview of Recent Developments in the Management of Burn Injuries

According to the World Health Organization (WHO), around 11 million people suffer from burns every year, and 180,000 die from them. A burn is a condition in which heat, chemical substances, an electrical current or other factors cause tissue damage. Burns mainly affect the skin, but can also affect deeper tissues such as bones or muscles. When burned, the skin loses its main functions, such as protection from the external environment, pathogens, evaporation and heat loss. Depending on the stage of the burn, the patient's condition and the cause of the burn, we need to choose the most appropriate treatment. Personalization and multidisciplinary collaboration are key to the successful management of burn patients. In this comprehensive review, we have collected and discussed the available treatment options, focusing on recent advances in topical treatments, wound cleansing, dressings, skin grafting, nutrition, pain and scar tissue management.

Clinical evaluation of intralesional umbilical cord-derived mesenchymal stem cells, conditioned medium and triamcinolone acetonide injection for keloid treatment: A pilot study

Topical keloid therapy is performed with triamcinolone acetonide (TA) intralesional injection. However, the recurrence rate is high with various side effects. Mesenchymal stem cells (MSCs) have high proliferative abilities and reduce the activity and proliferation of fibroblast cells in keloids. To overcome the costs and limitations, conditioned medium (CM) is used. This study aims to evaluate feasibility of intralesional injection of umbilical cord MSC (UC-MSC) and conditioned medium (UC-CM) compared to TA for keloid therapy. Twenty-four patients with keloids who met the inclusion criteria were included, randomized into three treatment groups and then got assessed for the sociodemographic data, keloid volume, histopathology (type 1:3 collagen ratio), interleukin-10 (IL-10) levels and Patient and Observer Scar Assessment Scale (POSAS) score during visits. Largest volume regression occurred in the UC-MSC group, followed by UC-CM and then the TA group (UC-MSC: 45.32% ± 2.61%; UC-CM: 43.61% ± 3.67%; TA: 28.34% ± 3.81%; p = 0.003). Similar pattern was also observed in increase in IL-10 levels, the decrease in POSAS scores and the reduction of type 1:3 collagen ratio. Hence, UC-MSC and UC-CM are promisingly more effective than TA for keloid therapy, showcasing their superiority in reducing keloid volume, symptoms and type 1:3 collagen ratio, as well as increasing the levels of IL-10.

Electric field promotes dermal fibroblast transdifferentiation through activation of RhoA/ROCK1 pathway

With the increased incidence of age-related and lifestyle-related diseases, chronic wounds are sweeping the world, where recent studies reveal that dysfunction of fibroblast plays an indispensable role. Endogenous electric field (EF) generated by skin wound disrupting an epithelial layer has been used as an alternative clinical treatment in chronic wound by modulating cellular behaviours, including fibroblasts transdifferentiation. Although many molecules and signaling pathways have been reported associated with fibroblasts transdifferentiation, studies investigating how the electric field affects the cellular pathways have been limited. For this purpose, a model of electric field treatment in vitro was established, where cells were randomly divided into control and electrified groups. The changes of protein expression and distribution were detected under different conditions, along with Zeiss imaging system observing the response of cells. Results showed that fibroblast transdifferentiation was accompanied by increased expression of a-SMA and extracellular matrix (COL-1 and COL-3) under the EF. Simultaneously, fibroblast transdifferentiation was also consistent with changes of cell arrangement and enhanced motility. Furthermore, we found that electric field activated RhoA signaling pathways activity. Y-27632, a RhoA inhibitor, which was used to treat fibroblasts, resulted in reduced transdifferentiation. The connection between electric field and RhoA signaling pathways is likely to be significant in modulating fibroblast transdifferentiation in acute injury and tissue remodeling, which provides an innovative idea for the molecular mechanism of EF in promoting chronic wound healing.

Stem cells in plastic surgery and aesthetic medicine

Stem cells (SCs) have multiple applications in today's medicine including aesthetic dermatology and plastic surgery. The purpose of this paper is to review some clinical use of mesenchymal SCs. The main focus was put on adipose tissue-derived stem cells (ADSCs) as these cells are easy to harvest and because of their properties showed great potential in many studies, where they proved to accelerate wound healing, reduce scars, cause hair regrowth, or rejuvenate skin. Furthermore, when added to lipofilling procedures, such as breast augmentation they enhance fat graft survival and provide satisfying results. Currently, many different strategies for using SCs in treatments are developed with great efficacy, however, there are still many limitations and concerns regarding their clinical use.

Mesenchymal stem cells in fibrotic diseases-the two sides of the same coin

Fibrosis is caused by extensive deposition of extracellular matrix (ECM) components, which play a crucial role in injury repair. Fibrosis attributes to ~45% of all deaths worldwide. The molecular pathology of different fibrotic diseases varies, and a number of bioactive factors are involved in the pathogenic process. Mesenchymal stem cells (MSCs) are a type of multipotent stem cells that have promising therapeutic effects in the treatment of different diseases. Current updates of fibrotic pathogenesis reveal that residential MSCs may differentiate into myofibroblasts which lead to the fibrosis development. However, preclinical and clinical trials with autologous or allogeneic MSCs infusion demonstrate that MSCs can relieve the fibrotic diseases by modulating inflammation, regenerating damaged tissues, remodeling the ECMs, and modulating the death of stressed cells after implantation. A variety of animal models were developed to study the mechanisms behind different fibrotic tissues and test the preclinical efficacy of MSC therapy in these diseases. Furthermore, MSCs have been used for treating liver cirrhosis and pulmonary fibrosis patients in several clinical trials, leading to satisfactory clinical efficacy without severe adverse events. This review discusses the two opposite roles of residential MSCs and external MSCs in fibrotic diseases, and summarizes the current perspective of therapeutic mechanism of MSCs in fibrosis, through both laboratory study and clinical trials.

From Chronic Wounds to Scarring: The Growing Health Care Burden of Under- and Over-Healing Wounds

Significance: Wound healing is the largest medical market without an existing small molecule/drug treatment. Both "under-healing" (chronic wounds) and "over-healing" (scarring) cause a substantial biomedical burden and lifelong consequences for patients. These problems cost tens of billions of dollars per year in the United States alone, a number expected to grow as the population ages and the prevalence of common comorbidities (e.g., diabetes) rises. However, no therapies currently exist to produce the "ideal" healing outcome: efficient wound repair through regeneration of normal tissue. Recent Advances: Ongoing research continues to illuminate possible therapeutic avenues for wound healing. By identifying underlying mechanisms of wound repair-for instance, tissue mechanics' role in fibrosis or cell populations that modulate wound healing and scarring-novel molecular targets may be defined. This Advances in Wound Care Forum issue includes reviews of scientific literature and original research from the Hagey Laboratory for Pediatric Regenerative Medicine at Stanford and its alumni, including developing approaches for encouraging wound healing, minimizing fibrosis, and coaxing regeneration. Critical Issues: Wound healing problems reflect an enormous and rapidly expanding clinical burden. The issues of both under- and over-healing wound outcomes will continue to expand as their underlying causes (e.g., diabetes) grow. Targeted treatments are needed to enable wound repair with functional tissue restoration and decreased scarring. Future Directions: Basic scientists will continue to refine understanding of factors driving undesirable wound outcomes. These discoveries are beginning to be translated and, in the coming years, will hopefully form the foundation for antiscarring drugs and other wound therapeutics.

Use of Adipose Stem Cells Against Hypertrophic Scarring or Keloid

Hypertrophic scars or keloid form as part of the wound healing reaction process, and its formation mechanism is complex and diverse, involving multi-stage synergistic action of multiple cells and factors. Adipose stem cells (ASCs) have become an emerging approach for the treatment of many diseases, including hypertrophic scarring or keloid, owing to their various advantages and potential. Herein, we analyzed the molecular mechanism of hypertrophic scar or keloid formation and explored the role and prospects of stem cell therapy, in the treatment of this condition.

A critical review on the potential role of adipose-derived stem cells for future treatment of hypertrophic scars

INTRODUCTION

Adipose-derived stem cells (ASCs) have recently gained researchers' interest as a solution to various diseases and conditions, including hypertrophic scar. This literature review aims to elucidate ASCs as a potential solution to alleviate hypertrophic scar in human subjects.

METHODS

Literature search was done in databases which includes PubMed, MEDLINE, and ProQuest using terms 'adipose derived stem cells', 'adipose cells', 'fat graft', 'fat grafting', 'autologous fat graft', 'fat injection', 'lipofilling', 'scar management', 'scar treatment', 'burn scar', and 'wound management'. The included articles which were published during year 2000-November 2020 must describe the use of ASCs or fat grafting or lipofilling as an attempt to alleviate hypertrophic scar.

REMARKS

Clinically, ASCs improve hypertrophic scars in terms of scar color, elasticity, texture, thickness, and size. Histologically, ASCs promotes healthy tissue regeneration, reduction in fibroblasts, and reorganisation of collagen, resembling those of normal skin. In terms of molecular aspects, ASCs alleviates hypertrophic scars through direct differentiation and paracrine mechanisms.

CONCLUSION

Adipose-derived stem cells, emerge to be a potential solution for alleviating hypertrophic scar, as demonstrated in various studies. However, there has been no studies conducted in human subjects to investigate the effect of ASCs on hypertrophic scar.

Comparative analysis of the immunomodulatory potential of caprine fetal adnexa derived mesenchymal stem cells

The caprine mesenchymal stem cells (MSCs) derived from fetal adnexa are highly proliferative. These cells possess tri-lineage differentiation potential and express MSC surface antigens and pluripotency markers with a wound-healing potential. This present study was conducted to compare the immunomodulatory potential of caprine MSCs derived from the fetal adnexa. Mid-gestation caprine uteri (2-3 months) were collected from the abattoir to isolate MSCs from amniotic fluid (cAF), amniotic sac (cAS), Wharton's jelly (cWJ) and cord blood (cCB), which were expanded and characterized at the 3^rd passage. These MSCs were then stimulated with inflammatory cytokines (IFN-γ and TNF-α) to assess the percentage of inhibition produced on peripheral blood mononuclear cells (PBMCs) proliferation. The percentage of inhibition on activated PBMCs proliferation produced by cWJ MSCs and cAS MSCs was significantly higher than cCB and cAF MSCs. The relative mRNA expression profile and immunofluorescent localization of different immunomodulatory cytokines and growth factors were conducted upon stimulation. The mRNA expression profile of a set of different cytokines and growth factors in each caprine fetal adnexa MSCs were modulated. Indoleamine 2, 3 dioxygenase appeared to be the major immunomodulator in cWJ, cAF, and cCB MSCs whereas inducible nitric oxide synthase in cAS MSCs. This study suggests that caprine MSCs derived from fetal adnexa display variable immunomodulatory potential, which appears to be modulated by different molecules among sources.

In Vitro Activation and Development of Goat Preantral Follicles Enclosed in Ovarian Tissue Co-cultured with Mesenchymal Stem Cells

The development of culture systems capable of maintaining follicular growth since the preantral stage has been the target of investigations. Mesenchymal stem cells (MSC) present potential for use in a wide range of applications, including research aimed at preserving fertility. Therefore, this study investigated the use of caprine Wharton's Jelly Mesenchymal Stem Cells (WJMSC) on the survival and in vitro development of goat preantral follicles enclosed in ovarian fragments cultured for 1 or 7 days. Fragments of the ovarian cortex were immediately fixed (non-cultured control) or distributed in four treatments: ovarian tissue cultured in control medium (α-MEM⁺); ovarian tissue cultured in α-MEM⁺ supplemented with FBS (α-MEM⁺ + FBS); ovarian tissue co-cultured with stem cells in α-MEM⁺ (α-MEM⁺ + SC); and ovarian tissue co-cultured with stem cell in α-MEM⁺ + FBS (α-MEM⁺ + SC + FBS). The rates of cell proliferation, follicular survival, and activation, as well as follicular diameter, were evaluated. After 7 days, the treatment co-cultured with stem cells showed a higher (P < 0.05) percentage of morphologically normal preantral follicles compared to the other treatments, as well as a higher (P < 0.05) activation rate compared to cultured control. Moreover, the follicular diameter was higher (P < 0.05) in the treatment co-cultured with stem cells compared to co-cultured with stem cells plus FBS. This study demonstrates for the first time that in vitro co-culture of caprine WJMSC with preantral follicles enclosed in goat ovarian tissue improves activation and early follicular development.

Emerging and Novel Therapies for Keloids: A compendious review

Keloids are abnormal fibroproliferative scars with aggressive dermal growth expanding beyond the borders of the original injury. Different therapeutic modalities, such as corticosteroids, surgical excision, topical silicone gel sheeting, laser therapy, cryotherapy, photodynamic therapy and radiotherapy, have been used to treat keloids; however, none of these modalities has proven completely effective. Recently, researchers have devised several promising anti-keloid therapies including anti-hypertensive pharmaceuticals, calcineurin inhibitors, electrical stimulation, mesenchymal stem cell therapy, microneedle physical contact and ribonucleic acid-based therapies. The present review summarises emerging and novel treatments for keloids. PubMed^® (National Library of Medicine, Bethesda, Maryland, USA), EMBASE (Elsevier, Amsterdam, Netherlands) and Web of Science (Clarivate Analytics, Philadelphia, Pennsylvania, USA) were searched for relevant literature published between January 1987 to June 2020. A total of 118 articles were included in this review. A deeper understanding of the molecular mechanisms underlying keloid scarring pathogenesis would open further avenues for developing innovative treatments.

Adiponectin-Based Peptide (ADP355) Inhibits Transforming Growth Factor-β1-Induced Fibrosis in Keloids

Keloids, benign cutaneous overgrowths of dermal fibroblasts, are caused by pathologic scarring of wounds during healing. Current surgical and therapeutic modalities are unsatisfactory. Although adiponectin has shown an antifibrotic effect, its large size and insolubility limit its potential use in keloid treatment. We investigated the effect of a smaller and more stable adiponectin-based peptide (ADP355) on transforming growth factor β1 (TGF-β1)-induced fibrosis in a primary culture of keloid fibroblasts prepared from clinically obtained keloid samples. Xenograft of keloid tissues on athymic nude mice was used to investigate the effect of intralesional injection of ADP355. ADP355 significantly attenuated the TGF-β1-induced expression of procollagen type 1 in keloid fibroblasts (p < 0.05). Moreover, it inhibited the TGF-β1-induced phosphorylation of SMAD3 and ERK, while amplifying the phosphorylation of AMP-activated protein kinase (p < 0.05). Knockdown of adiponectin receptor 1 reversed the attenuation of procollagen expression in ADP355-treated TGF-β1-induced fibrosis (p < 0.05). ADP355 also significantly reduced the gross weight and procollagen expression of keloid tissues in xenograft mice compared to control animals. These results demonstrate the therapeutic potential of the adiponectin peptide ADP355 for keloids.

Application of 3D Printed Models of Complex Hypertrophic Scars for Preoperative Evaluation and Surgical Planning

Background

Complex hypertrophic scar is a condition that causes multiple joint contractures and deformities after trauma or burn injuries. Three-dimensional (3D) printing technology provides a new evaluation method for this condition. The objective of this study was to print individualized 3D models of complex hypertrophic scars and to assess the accuracy of these models.

Methods

Twelve patients with complex hypertrophic scars were included in this study. Before surgery, each patient underwent a computed tomography (CT) scan to obtain cross-sectional information for 3D printing. Mimics software was used to process the CT data and create 3D printed models. The length, width, height, and volume measurements of the physical scars and 3D printed models were compared. Experienced surgeons used the 3D models to plan the operation and simulate the surgical procedure. The hypertrophic scar was completely removed for each patient and covered with skin autografts. The surgical time, bleeding, complications, and skin autograft take rate were recorded. All patients were followed up at 12 months. The surgeons, young doctors, medical students, and patients involved in the study completed questionnaires to assess the use of the 3D printed models.

Results

The 3D models of the hypertrophic scars were printed successfully. The length, width, height, and volume measurements were significantly smaller for the 3D printed models than for the physical hypertrophic scars. Based on preoperative simulations with the 3D printed models, the surgeries were performed successfully and each hypertrophic scar was completely removed. The surgery time was shortened and the bleeding was decreased. On postoperative day 7, there were two cases of subcutaneous hemorrhage, one case of infection and one case of necrosis. On postoperative day 12, the average take rate of the skin autografts was 97.75%. At the 12-month follow-up, all patients were satisfied with the appearance and function.

Conclusion

Accurate 3D printed models can help surgeons plan and perform successful operations, help young doctors and medical students learn surgical methods, and enhance patient comprehension and confidence in their surgeons.

Hematoporphyrin monomethyl ether-mediated photodynamic therapy inhibits the growth of keloid graft by promoting fibroblast apoptosis and reducing vessel formation

Photodynamic therapy (PDT) has been shown to significantly inhibit fibroblast activity. However, the effect of PDT mediated by the photosensitizer hematoporphyrin monomethyl ether (HMME) on keloids is not known well. The aim of our study was to examine the efficacy of HMME-PDT in cellular and animal models of keloids. Keloid fibroblasts (KFbs) were isolated from human keloid specimens and the proliferation, invasion, and migration of KFbs after HMME-PDT treatment was examined in vitro. Apoptosis in cells was measured by flow cytometry. Cysteinyl aspartate specific proteinase 3 (Caspase3) expression was determined by immunofluorescence staining and western blot. HMME-PDT inhibited KFbs proliferation, invasion, migration, increased apoptosis rate and enhanced caspase3 and cleaved caspase3 expression. The keloid graft transplantation was performed by using nude mice. The growth of the graft was monitored every third day. Interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) mRNA expression were detected by quantitative real time PCR. It was observed that HMME-PDT attenuated graft growth and reduced vessel density in the keloid grafts. However, HMME-PDT did not alter IL-6 and TNF-α mRNA expression in the keloid grafts. Moreover, HMME-PDT suppressed transforming growth-β1 (TGF-β1) and small phenotype and Drosophila Mothers Against Decapentaplegic 3 (Smad3) expression in both KFbs and keloid grafts. Collectively, the evidence suggests that HMME-PDT inhibits the growth of the keloid graft by promoting the apoptosis of fibroblasts and reducing vessel formation of the keloid graft.

Stem Cells in Keloid Lesions: A Review

Keloid disorder (KD) is a fibroproliferative condition caused by dysregulated wound healing following wounding of the skin. The pathogenesis of KD has not been fully elucidated and current treatment is unsatisfactory. There is increasing evidence of the role of stem cells in KD. This review discusses the role of embryonic stem (ESC)-like cells and mesenchymal stem cells in the pathogenesis of KD. It is proposed that dysfunction of the ESC-like population localized to the endothelium of the microvessels and perivascular cells within the keloid-associated lymphoid tissues may give rise to the aberrant fibroblasts and myofibroblasts via a mesenchymal stem cell intermediate in keloid lesions, by undergoing an endothelial-to-mesenchymal transition. We also discuss the role of the renin-angiotensin system (RAS), the immune system, and the inflammatory response, on stem cell proliferation and differentiation. The understanding of the precise roles of these stem cells and interplay of the associated regulatory pathways could lead to the development of targeted therapy for this enigmatic and challenging condition. The demonstration of the expression of components of the RAS and cathepsins B, D, and G that constitute bypass loops of the RAS, by the ESC-like population, suggests that the primitive population may be a therapeutic target by modulation of the RAS, using existing medications.

Managing Pathologic Scars by Injecting Auto-Cross-linked Hyaluronic Acid: A Preliminary Prospective Clinical Study

BACKGROUND

Pathological scars are unattractive and may significantly impair the patient's quality of life. Current treatments provide inconsistent results, and none may be regarded as definitive. Recently, an auto-cross-linked hyaluronic acid (HA) formulation, IAL-SYSTEM ACP, featuring a long residence time and an enhanced safety profile, has been successfully used to prevent surgical adhesions, treat tendon lesions and rejuvenate the face and the décolletage. This study aims to preliminarily investigate whether IAL-SYSTEM ACP may also be effective in treating pathological scars resulting from burns, trauma or iatrogenic causes.

METHODS

Patients presenting one pathological scar were prospectively recruited and treated with two IAL-SYSTEM ACP injections carried out two weeks apart. Scar improvement was measured comparing the patient and observer scar assessment scale (POSAS) scores collected before treatment (T0) and 90 days after the second injection (T90) using nonparametric tests. The effect of age and scar type over score variation was investigated through quantile regression analysis.

RESULTS

Forty-one patients, 10 women and 31 men (median age, 34 years) were recruited. No patient dropped out, and no significant adverse event was observed. At T90, the median observer total score decreased by 11 units (- 77.5%) and the median patient total score decreased by 15 units (- 73.7%). The difference was significant (p < 0.001) in both cases. Traumatic injuries and young patient's age were the most significant predictors of a positive treatment outcome.

CONCLUSIONS

Treatment of pathological scars by two IAL-SYSTEM ACP injections, carried out two weeks apart, may provide significant clinical benefits. These findings should be the subject of further investigations.

LEVEL OF EVIDENCE IV

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 .

The effects of graphene and mesenchymal stem cells in cutaneous wound healing and their putative action mechanism

This study provides a review of the therapeutic potential of graphene dressing scaffolds and mesenchymal stem cells (MSCs) and their synergistic effects with respect to cutaneous wound healing. This study also considers their putative action mechanism based on the antibacterial, immunomodulating, angiogenic, matrix remodeling effects of materials belonging to the graphene family and MSCs during the wound healing process. In addition, this study discusses the cytocompatibility of graphene, its uses as a platform for skin substitutes, the properties it possesses with respect to providing protection against microbial invasion as well as strategies aimed at minimizing the chance of the occurrence of sepsis. MSCs are capable of secreting several factors that exert a therapeutic impact on reparative processes and tissue regeneration. In light of experiments conducted to date, graphene combined with MSCs appears to have the potential to enhance both the wound healing process and infection control at the injury site.

Cell sheet composed of adipose-derived stem cells demonstrates enhanced skin wound healing with reduced scar formation

Scar formation remains a major clinical concern following tissue injuries such as skin wounds. Adipose-derived stem cell (ASC) sheets can be fabricated quickly through stimulation with l-ascorbate 2-phosphate and have valuable applications in tissue regeneration and wound healing. However, the antifibrotic capability of ASCs in cell sheet format has not been sufficiently investigated. We employed a murine model of healing-impaired cutaneous wounds and observed faster wound healing with ASC sheet treatment. Significantly more engrafted ASCs were observed in the wound tissue treated with ASC sheets at 14 days after wounding compared with dissociated cells. Moreover, no ASCs were found at day 28, which indicated a minimal risk of long-term side effects. The neoskin formed in the presence of ASC sheets exhibited a thickness comparable to normal skin and possessed a highly organized collagen structure. ASC sheets also suppressed macrophage infiltration and modulated TNF-α and TGF-β1 expression in vivo. Examination of fibroblasts cultured in ASC-conditioned medium indicated an anti-scarring effect of the ASC sheets evidenced by the downregulation of TGF-β1 and α-SMA in fibroblasts, which was likely mediated through the increased secretion of hepatocyte growth factor. Moreover, ASC sheets secreted significantly more C1q/TNF-related protein-3, which inhibited the C-C motif ligand 2 release by macrophages in vitro and subsequently reduced the chemotaxis of unstimulated macrophages. This mechanism may account for the observed decrease in recruitment of macrophages into the wound tissue. We conclude that ASC sheets possess the necessary paracrine factors to improve skin wound healing with a superior neoskin quality.

STATEMENT OF SIGNIFICANCE

Adipose-derived stem cell (ASC) sheets exhibit great potential for tissue regeneration. In this study, we investigated whether ASC sheets can ameliorate skin wound healing with reduced scar formation, and faster wound healing was observed when applying ASC sheets in an impaired wound healing model of mice. The neoskin formed in the presence of ASC sheets exhibited a thickness comparable to normal skin with a more organized collagen structure. In vitro experiments suggested that the anti-scarring effect of the ASC sheets was partly mediated through increased secretion of hepatocyte growth factor. Moreover, ASC sheets secreted significantly more C1q/TNF-related protein-3, which may account for the decreased recruitment of macrophages into the wound tissue. Therefore, ASC sheets possess the necessary paracrine factors to improve skin wound healing with less scarring, thus representing a desirable method of topical wound treatment.

Growth hormone-releasing peptide 6 prevents cutaneous hypertrophic scarring: early mechanistic data from a proteome study

Hypertrophic scars (HTS) and keloids are forms of aberrant cutaneous healing with excessive extracellular matrix (ECM) deposition. Current therapies still fall short and cause undesired effects. We aimed to thoroughly evaluate the ability of growth hormone releasing peptide 6 (GHRP6) to both prevent and reverse cutaneous fibrosis and to acquire the earliest proteome data supporting GHRP6's acute impact on aesthetic wound healing. Two independent sets of experiments addressing prevention and reversion effects were conducted on the classic HTS model in rabbits. In the prevention approach, the wounds were assigned to topically receive GHRP6, triamcinolone acetonide (TA), or vehicle (1% sodium carboxy methylcellulose [CMC]) from day 1 to day 30 post-wounding. The reversion scheme was based on the infiltration of either GHRP6 or sterile saline in mature HTS for 4 consecutive weeks. The incidence and appearance of HTS were systematically monitored. The sub-epidermal fibrotic core area of HTS was ultrasonographically determined, and the scar elevation index was calculated on haematoxylin/eosin-stained, microscopic digitised images. Tissue samples were collected for proteomics after 1 hour of HTS induction and treatment with either GHRP6 or vehicle. GHRP6 prevented the onset of HTS without the untoward reactions induced by the first-line treatment triamcinolone acetonide (TA); however, it failed to significantly reverse mature HTS. The preliminary proteomic study suggests that the anti-fibrotic preventing effect exerted by GHRP6 depends on different pathways involved in lipid metabolism, cytoskeleton arrangements, epidermal cells' differentiation, and ECM dynamics. These results enlighten the potential success of GHRP6 as one of the incoming alternatives for HTS prevention.

Recent Understandings of Biology, Prophylaxis and Treatment Strategies for Hypertrophic Scars and Keloids

Hypertrophic scars and keloids are fibroproliferative disorders that may arise after any deep cutaneous injury caused by trauma, burns, surgery, etc. Hypertrophic scars and keloids are cosmetically problematic, and in combination with functional problems such as contractures and subjective symptoms including pruritus, these significantly affect patients’ quality of life. There have been many studies on hypertrophic scars and keloids; but the mechanisms underlying scar formation have not yet been well established, and prophylactic and treatment strategies remain unsatisfactory. In this review, the authors introduce and summarize classical concepts surrounding wound healing and review recent understandings of the biology, prevention and treatment strategies for hypertrophic scars and keloids.

Adiponectin Is Involved in Connective Tissue Growth Factor-Induced Proliferation, Migration and Overproduction of the Extracellular Matrix in Keloid Fibroblasts

Adiponectin, an adipocyte-derived hormone, exerts pleiotropic biological effects on metabolism, inflammation, vascular homeostasis, apoptosis and immunity. Recently, adiponectin has been suggested to attenuate the progression of human dermal fibrosis. Connective tissue growth factor (CTGF) is induced in keloids and is thought to be participated in the formation of keloid fibrosis. However, the roles played by adiponectin in keloids remain unclear. In this study, we explored the effects of adiponectin on CTGF-induced cell proliferation, migration and the deposition of extracellular matrix (ECM) and their associated intracellular signalling pathways in keloid fibroblasts (KFs). We also explored possible mechanisms of keloid pathogenesis. Primary fibroblast cultures were established from foreskin biopsies and skin biopsies from patients with keloids. The expression of adiponectin and adiponectin receptors (adipoRs) was evaluated by reverse transcription-PCR (RT-PCR), quantitative real-time RT-PCR, immunofluorescence staining, and immunohistochemical analysis. Next, KFs and normal dermal fibroblasts (NFs) were treated with CTGF in the presence or absence of adiponectin. A cell counting kit-8 (CCK-8) and the Transwell assay were used to examine cell proliferation and migration. The level of the collagen I, fibronectin (FN) and α-smooth muscle actin (α-SMA) mRNAs and proteins were determined by quantitative real-time RT-PCR and western blotting. The effects of RNA interference (RNAi) targeting the adipoR genes were detected. Phosphorylation of adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK), mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3 kinase-protein kinase (PI3K-Akt) were examined by western blotting to further investigate the signalling pathways. Furthermore, inhibitors of signal transduction pathways were investigated. The expression levels of adiponectin and adipoRs were significantly decreased in keloids compared with those in normal skin tissue. Adiponectin suppressed the CTGF-induced KFs, but not NFs, proliferation, migration and ECM production. Moreover, adiponectin inhibited the phosphorylation of AMPK, p38 and extracellular-regulated kinase (ERK), but not that of Jun N-terminal kinase (JNK) or Akt, in CTGF-treated KFs. The activity of adiponectin-mediated signalling pathways was attenuated by small interfering RNAs (siRNAs) targeting adipoR1 (but not siRNAs targeting adipoR2, T-cadherin or calreticulin), AMPK (Compound C), p38 (SB203580) inhibitors, and mitogen-activated protein kinase kinase (MEK) inhibitor (PD98059). Based on our results, adiponectin suppresses CTGF-induced KFs proliferation, migration and ECM overproduction. One of the underlying mechanisms is the activation of the adipoR1, AMPK, p38, and ERK signalling pathways. Therefore, adiponectin may play an important role in the progression of keloids, suggesting a potential novel target for keloid treatment.

The Selective Centrifugation Ensures a Better In Vitro Isolation of ASCs and Restores a Soft Tissue Regeneration In Vivo

Autologous fat grafting procedures in plastic surgery have been extensively used to reinforce soft tissue in congenital or acquired tissue impairments. With this background, the aim of this study is firstly to examine the impact of a selective centrifugation on existing adipose stem cells (ASCs) in terms of stemness profile maintenance and, secondly, to investigate the effect of restoring volume in reconstruction on patients affected by soft tissue damage. After centrifugation, the fat graft products were separated into two layers and subsequently examined in vitro for the expression of CD34, CD90, CD117, CD105, CD29, CD31, CD44, CD73, CD133, CD14 and CD45 markers by flow cytometry and gene expression analyses were performed for Sox2, WNT3A, END, CD44, FUT4, COLL1, CTNNB1, hbEGF, KRTLG, MMP2 and VIM genes. The results showed that in the middle-high density (MHD) layer there was a peak concentration of ASCs, compared to another layer obtained after centrifugation. Research carried out on patients under treatment for soft tissue regeneration using cells obtained from MHD layer selection will be fundamental in comparative analysis. These studies will lead to an adequate standardization of outcomes, provided that treatment is performed through cell selection. Therefore, a unique procedure in tissue reconstruction and regeneration through fat grafting is presented here.

Keloid and Hypertrophic Scars Are the Result of Chronic Inflammation in the Reticular Dermis

Keloids and hypertrophic scars are caused by cutaneous injury and irritation, including trauma, insect bite, burn, surgery, vaccination, skin piercing, acne, folliculitis, chicken pox, and herpes zoster infection. Notably, superficial injuries that do not reach the reticular dermis never cause keloidal and hypertrophic scarring. This suggests that these pathological scars are due to injury to this skin layer and the subsequent aberrant wound healing therein. The latter is characterized by continuous and histologically localized inflammation. As a result, the reticular layer of keloids and hypertrophic scars contains inflammatory cells, increased numbers of fibroblasts, newly formed blood vessels, and collagen deposits. Moreover, proinflammatory factors, such as interleukin (IL)-1α, IL-1β, IL-6, and tumor necrosis factor-α are upregulated in keloid tissues, which suggests that, in patients with keloids, proinflammatory genes in the skin are sensitive to trauma. This may promote chronic inflammation, which in turn may cause the invasive growth of keloids. In addition, the upregulation of proinflammatory factors in pathological scars suggests that, rather than being skin tumors, keloids and hypertrophic scars are inflammatory disorders of skin, specifically inflammatory disorders of the reticular dermis. Various external and internal post-wounding stimuli may promote reticular inflammation. The nature of these stimuli most likely shapes the characteristics, quantity, and course of keloids and hypertrophic scars. Specifically, it is likely that the intensity, frequency, and duration of these stimuli determine how quickly the scars appear, the direction and speed of growth, and the intensity of symptoms. These proinflammatory stimuli include a variety of local, systemic, and genetic factors. These observations together suggest that the clinical differences between keloids and hypertrophic scars merely reflect differences in the intensity, frequency, and duration of the inflammation of the reticular dermis. At present, physicians cannot (or at least find it very difficult to) control systemic and genetic risk factors of keloids and hypertrophic scars. However, they can use a number of treatment modalities that all, interestingly, act by reducing inflammation. They include corticosteroid injection/tape/ointment, radiotherapy, cryotherapy, compression therapy, stabilization therapy, 5-fluorouracil (5-FU) therapy, and surgical methods that reduce skin tension.