The Effect of Myofibroblast on Contracture of Hypertrophic Scar

The Modulation of Fibrosis in Vocal Fold Repair: A Study on c-Met Agonistic Antibodies and Hepatocyte Growth in Animal Studies

Background and Objectives: Damage to the vocal folds frequently results in fibrosis, which can degrade vocal quality due to the buildup of collagen and modifications in the extracellular matrix (ECM). Conventional treatments have shown limited success in reversing fibrotic changes. Hepatocyte growth factor (HGF) and c-Met-targeting antibodies are promising due to their potential to inhibit fibrosis and promote regeneration. This research examines the effectiveness of injections containing c-Met agonistic antibodies relative to HGF in reducing fibrosis within a rat model of vocal fold injury. Materials and Methods: Forty-five Sprague Dawley rats were divided into three groups, which were HGF, c-Met agonistic antibody, and the control (PBS). The right vocal folds were injured and treated with HGF or c-Met agonistic antibody injections. RNA isolation and quantitative real-time PCR were performed to assess mRNA levels of fibrosis-related markers at 1 and 2 weeks post-injury. Histopathological analysis was conducted at 3 weeks to evaluate collagen and hyaluronic acid (HA) deposition. Results: Both the HGF and c-Met groups demonstrated reduced type III collagen mRNA expression compared to the PBS group. The c-Met group uniquely maintained fibronectin levels closer to normal. Additionally, the c-Met group showed significantly upregulated expression of hyaluronan synthase (HAS) 1 and HAS 3 at 2 weeks post-injury, indicating enhanced HA synthesis. Histological analysis showed significantly lower collagen deposition and higher HA in the c-Met group than in PBS, confirming superior anti-fibrotic effects and ECM restoration. Conclusions: c-Met agonistic antibody injections outperformed HGF in reducing fibrosis, upregulating HAS expression, and promoting HA deposition in injured vocal folds, highlighting its potential as a superior therapeutic approach for preventing fibrosis and enhancing ECM quality in vocal fold injuries. Further research on functional outcomes in larger models is recommended to validate these findings.

Exposure of Primary Human Skin Fibroblasts to Carbon Dioxide-Containing Solution Significantly Reduces TGF-β-Induced Myofibroblast Differentiation In Vitro

Wound healing as a result of a skin injury involves a series of dynamic physiological processes, leading to wound closure, re-epithelialization, and the remodeling of the extracellular matrix (ECM). The primary scar formed by the new ECM never fully regains the original tissue's strength or flexibility. Moreover, in some cases, due to dysregulated fibroblast activity, proliferation, and differentiation, the normal scarring can be replaced by pathological fibrotic tissue, leading to hypertrophic scars or keloids. These disorders can cause significant physical impairment and psychological stress and represent significant challenges in medical management in the wound-healing process. The present study aimed to investigate the therapeutic effects of exogenously applied carbon dioxide (CO2) on fibroblast behavior, focusing on viability, proliferation, migration, and differentiation to myofibroblasts. We found that CO2 exposure for up to 60 min did not significantly affect fibroblast viability, apoptosis rate, or proliferation and migration capacities. However, a notable finding was the significant reduction in α-smooth muscle actin (α-SMA) protein expression, indicative of myofibroblast differentiation inhibition, following CO2 exposure. This effect was specific to CO2 and concentration as well as time-dependent, with longer exposure durations leading to greater reductions in α-SMA expression. Furthermore, the inhibition of myofibroblast differentiation correlated with a statistically significantly reduced glycolytic and mitochondrial energy metabolism, and as a result, with a reduced ATP synthesis rate. This very noticeable decrease in cellular energy levels seemed to be specific to CO2 exposure and could not be observed in the control cultures using nitrogen (N2)-saturated solutions, indicating a unique and hypoxia-independent effect of CO2 on fibroblast metabolism. These findings suggest that exogenously applied CO2 may possess fibroblast differentiation-reducing properties by modulating fibroblast's energy metabolism and could offer new therapeutic options in the prevention of scar and keloid development.

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.

In vitro and in vivo Evaluation of Antifibrotic Properties of Verteporfin in a Composition of a Collagen Scaffold

Extensive skin damage requires specialized therapy that stimulates regeneration processes without scarring. The possibility of using combination of a collagen gel application as a wound dressing and fibroblast attractant with verteporfin as an antifibrotic agent was examined in vivo and in vitro. In vitro effects of verteporfin on viability and myofibroblast markers expression were evaluated using fibroblasts isolated from human scar tissue. In vivo the collagen gel and verteporfin (individually and in combination) were applied into the wound to investigate scarring during skin regeneration: deviations in skin layer thickness, collagen synthesis, and extracellular matrix fibers were characterized. The results indicate that verteporfin reduces fibrotic phenotype by suppressing expression of the contractile protein Sm22α without inducing cell death. However, administration of verteporfin in combination with the collagen gel disrupts its ability to direct wound healing in a scarless manner, which may be related to incompatibility of the mechanisms by which collagen and verteporfin control regeneration.

Hypertrophic Scar

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

Investigation of the "Surgical Cuts CO2 Laser Therapy Technique" to Treat Minor Burn Scar Contractures in Children

Fractional carbon dioxide (CO2) laser therapy has been shown to improve scar contractures following burns. However, the benefits of using other CO2 laser techniques to treat burn scar contractures are relatively unknown. This pilot study investigated a CO2 laser technique in which a series of perpendicular "surgical cuts" were created along the contracture. The aim of this study was to evaluate the effectiveness of using the "surgical cuts CO2 laser technique" in pediatric patients. This study included 12 participants with minor hand burn scar contractures that received one CO2 laser treatment using the surgical cuts technique. Trained assessors measured contractures pre- and post-laser therapy by assessing range of motion (ROM), digit length, and/or hand-span. All contractures were secondary to contact burns with the mean participant age equal to 5.5 years (SD 3.9). For all participants, at least one of the measured characteristics (ROM, hand-span, and digit length) improved after treatment. This pilot study demonstrated the benefit of using the surgical cuts CO2 laser technique to treat minor burn scar contractures. Future investigations are needed to further evaluate its effectiveness in comparison to the fractional CO2 laser therapy technique.

Local application of triamcinolone acetonide-conjugated chitosan membrane to prevent benign biliary stricture

Benign biliary stricture (BBS) is the proliferation of fibrous tissue of the biliary tract caused by the biliary operation, bile duct stones, cholangitis, trauma, and other etiologies due to scar contracture. Recent therapeutic strategies to suppress stenosis are insufficient. Here, we developed a sustained-release membrane (SM) of triamcinolone acetonide (TA) with N-succinyl hydroxypropyl chitosan (TASM) for inhibiting fibroblast proliferation in vitro and bile duct hyperplasia in the rabbit model for benign biliary stricture formation. The TASM were successfully placed in 45 of 50 rabbits. Evaluation of subcutaneous stimulation and acute liver injury confirms the safety of TASM in vivo. Compared to the control group, the TASM can significantly inhibit the proliferation of scar muscle fibroblasts in vitro. ELISA and immunofluorescence showed TASM could increase bFGF level and inhibit expression of TGFβ1 and αSMA. Cholangiographic and histologic examinations demonstrated significantly decreased tissue hyperplasia in the TASM groups compared with the model group. The immunohistochemical staining showed that TASM could reduce the level of cytokine-induced scars and inhibit the proliferation of myofibroblasts. Taken together, the chitosan membrane chemically conjugated with TA can effectively inhibit the benign biliary stricture. Further clinical usage of this membrane may effectively reduce the occurrence of benign biliary stricture.

Therapeutic Potential of Adipose Stem Cell-Derived Conditioned Medium on Scar Contraction Model

Scars are composed of stiff collagen fibers, which contract strongly owing to the action of myofibroblasts. To explore the substances that modulate scar contracture, the fibroblast-populated collagen lattice (FPCL) model has been used. However, the molecular signature of the patient-derived FPCL model has not been verified. Here, we examined whether the patient-derived keloid FPCL model reflects scar contraction, analyzing detailed gene expression changes using comprehensive RNA sequencing and histological morphology, and revealed that these models are consistent with the changes during human scar contracture. Moreover, we examined whether conditioned media derived from adipose stem cells (ASC-CM) suppress the scar contracture of the collagen disc. Detailed time-series measurements of changes in disc area showed that the addition of ASC-CM significantly inhibited the shrinkage of collagen discs. In addition, a deep sequencing data analysis revealed that ASC-CM suppressed inflammation-related gene expression in the early phase of contraction; in the later phase, this suppression was gradually replaced by extracellular matrix (ECM)-related gene expression. These lines of data suggested the effectiveness of ASC-CM in suppressing scar contractures. Therefore, the molecular analysis of the ASC-CM actions found in this study will contribute to solving medical problems regarding pathological scarring in wound prognosis.

Investigation of the long-term healing response of the liver to boiling histotripsy treatment in vivo

Boiling histotripsy (BH) is a promising High-Intensity Focused Ultrasound technique that can be employed to mechanically fractionate solid tumours. Whilst studies have shown the feasibility of BH to destroy liver cancer, no study has reported on the healing process of BH-treated liver tissue. We therefore extensively investigated the evolution of the healing response of liver to BH in order to provide an insight into the healing mechanisms. In the present study, 14 Sprague Dawley rats underwent the BH treatment and were sacrificed on days 0, 3, 7, 14, and 28 for morphological, histological, serological and qPCR analyses. The area of the treated region was 1.44 cm² (1.2 cm × 1.2 cm). A well-defined BH lesion filled with coagulated blood formed on day 0. A week after the treatment, fibroblast activation was induced at the treatment site, leading to the formation of extracellular matrix structure (ECM). The ECM was then disrupted for 7 to 28 days. Regenerated normal hepatocytes and newly formed blood vessels were found within the BH region with the absence of hepatic fibrosis. No significant morphological, histological and genetic changes around the BH lesion occurred. These results suggest that BH could be a safe and promising therapeutic tool for treating solid tumours without inducing any significant adverse effect such as the formation of liver fibrosis.

Lycorine Inhibits Hypertrophic Scar Formation by Inducing ROS-Mediated Apoptosis

Background: Hypertrophic scar (HS) is a fibrotic cutaneous disease with few effective therapies. Lycorine is a drug with pro-apoptotic ability and anti-fibrosis potential. This study aimed to test whether lycorine could trigger the apoptosis of hypertrophic scar fibroblasts (HSFs) to inhibit HS formation.

Methods: The proapoptotic and anti-fibrosis effects of lycorine on the viability and apoptosis of human primary HSFs and their reactive oxygen species (ROS) production as well as a rabbit ear model of HS were determined by CCK-8, flow cytometry, Western blot, immunofluorescence, transwell migration, collagen gel contraction assays.

Results: Lycorine treatment selectively decreased the viability of HSFs, and induced their apoptosis, but not normal fibroblasts (NFs). Lycorine treatment increased the relative levels of Bax and cleaved PARP expression, cytochrome C cytoplasm translocation, but decreased Bcl-2, caspase-3 and caspase-9 expression, the mitochondrial membrane potential (MMP) in HSFs. Lycorine inhibited the migration and contraction of HSFs, and reduced the expression of collagen I, collagen III and α-SMA. Mechanistically, lycorine treatment stimulated high levels of ROS production, leading to apoptosis of HSFs while treatment with NAC, a ROS inhibitor, significantly mitigated or abrogated the pro-apoptotic and antifibrotic activity of lycorine in HSFs. Moreover, lycorine treatment mitigated the severity of HS in rabbit ears by inducing fibroblast apoptosis.

Conclusion: These results indicate that lycorine has a potent anti-fibrotic activity and is a potential drug for intervention of HS.

Strategies to Minimize Surgical Scarring: Translation of Lessons Learned from Bedside to Bench and Back

Significance: An understanding of the physiology of wound healing and scarring is necessary to minimize surgical scar formation. By reducing tension across the healing wound, eliminating excess inflammation and infection, and encouraging perfusion to healing areas, surgeons can support healing and minimize scarring. Recent Advances: Preoperatively, newer techniques focused on incision placement to minimize tension, skin sterilization to minimize infection and inflammation, and control of comorbid factors to promote a healing process with minimal scarring are constantly evolving. Intraoperatively, measures like layered closure, undermining, and tissue expansion can be taken to relieve tension across the healing wound. Appropriate suture technique and selection should be considered, and finally, there are new surgical technologies available to reduce tension across the closure. Postoperatively, the healing process can be supported as proliferation and remodeling take place within the wound. A balance of moisture control, tension reduction, and infection prevention can be achieved with dressings, ointments, and silicone. Vitamins and corticosteroids can also affect the scarring process by modulating the cellular factors involved in healing. Critical Issues: Healing with no or minimal scarring is the ultimate goal of wound healing research. Understanding how mechanical tension, inflammation and infection, and perfusion and hypoxia impact profibrotic pathways allows for the development of therapies that can modulate cytokine response and the wound extracellular microenvironment to reduce fibrosis and scarring. Future Directions: New tension-off loading topical treatments, laser, and dermabrasion devices are under development, and small molecule therapeutics have demonstrated scarless wound healing in animal models, providing a promising new direction for future research aimed to minimize surgical scarring.

Scar formation from the perspective of complexity science: a new look at the biological system as a whole

A burn wound is a complex systemic disease at multiple levels. Current knowledge of scar formation after burn injury has come from traditional biological and clinical studies. These are normally focused on just a small part of the entire process, which has limited our ability to sufficiently understand the underlying mechanisms and to predict systems behaviour. Scar formation after burn injury is a result of a complex biological system-wound healing. It is a part of a larger whole. In this self-organising system, many components form networks of interactions with each other. These networks of interactions are typically non-linear and change their states dynamically, responding to the environment and showing emergent long-term behaviour. How molecular and cellular data relate to clinical phenomena, especially regarding effective therapies of burn wounds to achieve minimal scarring, is difficult to unravel and comprehend. Complexity science can help bridge this gap by integrating small parts into a larger whole, such that relevant biological mechanisms and data are combined in a computational model to better understand the complexity of the entire biological system. A better understanding of the complex biological system of post-burn scar formation could bring research and treatment regimens to the next level. The aim of this review/position paper is to create more awareness of complexity in scar formation after burn injury by describing the basic principles of complexity science and its potential for burn care professionals.

Extracellular Vesicles Derived From Human Adipose-Derived Stem Cell Prevent the Formation of Hypertrophic Scar in a Rabbit Model

Preventing scar formation during wound healing has important clinical implications. Numerous studies have indicated that adipose-derived stem cell culture mediums, which are rich in cytokines and extracellular vesicles (EVs), regulate matrix remodeling and prevent scar formation after wound healing. Therefore, using a rabbit scar model, we tried to demonstrate which factor in adipose-derived stem cell culture mediums plays a major role in preventing scar formation (EVs or cytokines), as well as revealing the underlying mechanism.

MiR-133a-3p inhibits scar formation in scalded mice and suppresses the proliferation and migration of scar derived-fibroblasts by targeting connective tissue growth factor

Excessive scar formation post burn injury can cause great pain to the patients. MiR-133a-3p has been demonstrated to be anti-fibrotic in some fibrosis-related diseases. However, its possible role in scar formation has not been elucidated yet. In present study, the effect of miR-133a-3p on scar formation was investigated in a scalded model of mice. Moreover, the function of miR-133a-3p on proliferation and migration of scar-derived fibroblasts (SFs) was studied in vitro. It was found that miR-133a-3p was dramatically downregulated in scar tissue of scalded mice. Upregulation of miR-133a-3p by miR-133a-3p agomir obviously inhibited the scar formation in scalded mice. Histological staining showed that upregulation of miR-133a-3p attenuated the excessive deposition of collagen in scar tissue of scalded mice. In vitro study showed that upregulation of miR-133a-3p effectively suppressed the proliferation and migration of SFs. Besides, upregulation of miR-133a-3p attenuated the protein levels of α-smooth muscle actin (α-SMA) and collagen I, indicating that miR-133a-3p could suppress the activation of SFs. The expression of connective tissue growth factor (CTGF), a critical mediator in cell proliferation, migration and extracellular matrix (ECM) synthesis, was also downregulated by the upregulation of miR-133a-3p. Luciferase reporter assay validated that CTGF was directly targeted by miR-133a-3p. In addition, overexpression of CTGF abolished the effect of miR-133a-3p on inhibiting the proliferation, migration and activation of SFs, indicating that miR-133a-3p functioned by targeting CTGF. Therefore, miR-133a-3p might be a promising target for treating pathological scars.

The Impact of Fibrin Sealant Volume on Skin Graft Contraction in a Full-Thickness Skin Graft Model

BACKGROUND

Fibrin sealant has been used for skin grafting in anatomically difficult facial areas. Although biodegradable, an excess of fibrin sealant may inhibit skin graft healing by inhibiting diffusion at the graft-recipient bed interface. The impact of fibrin sealant volume on graft healing was examined in a rat full-thickness skin graft model.

METHODS

Seventy-two full-thickness 2.5 × 2.5-cm skin grafts were used on the dorsum of male Sprague-Dawley rats. The grafts were treated with three different volumes of fibrin sealant placed onto the recipient bed: 0.0 mL or normal saline (group 1), 0.1 mL (group 2), and 0.4 mL (group 3). Graft healing and complications were assessed using digital photographs and necropsies on postoperative days 3, 7, and 21.

RESULTS

Group 3 showed the greatest graft contraction on days 3 and 21, while group 2 showed the least contraction on all 3 postoperative days (P = 0.002, 0.004, and <0.001, respectively). Histopathologic analysis showed inflammatory foreign body reactions in group 3 on days 3 and 7, and less vascular density on day 21 (P = 0.003). Group 1 showed the highest incidence of hematoma (P = 0.004).

CONCLUSION

An excess volume of fibrin sealant may produce pathologic wound contraction in skin grafting because a skin graft lacks a vascular pedicle and is highly dependent on diffusion from the host environment. Before using fibrin sealant for skin grafting in facial areas where the aesthetic outcome is important, the appropriate volume to use can be determined.

The effects of cross-linking a collagen-elastin dermal template on scaffold bio-stability and degradation

MatriDerm is a collagen-elastin dermal template that promotes regeneration in full-thickness wound repair. Due to its noncross-linked status, MatriDerm biodegrades quickly in a wound. Facilitating vascularization and dermal repair, it is desirable for MatriDerm to remain present until the wound healing process is complete, optimizing tissue regeneration and reducing wound contraction. The aim of this study was to investigate the effect of cross-linking MatriDerm on its mechanical and biological properties and to enhance its regenerative functionality. MatriDerm was chemically cross-linked and characterized in comparison with noncross-linked MatriDerm. Scaffold properties including surface morphology, protein release and mechanical strength were assessed. Cell-scaffold interaction, cell proliferation and migration were examined using human dermal fibroblasts. Scaffold biodegradation and its impact on wound healing and contraction were studied in a mouse model. Results showed that cross-linked MatriDerm displayed a small reduction in pore size, significantly less protein loss and a threefold increase in tensile strength. A significant increase in fibroblast proliferation and migration was observed in cross-linked MatriDerm with reduced scaffold contraction in vitro. In the mouse model, noncross-linked MatriDerm was almost completely biodegraded after 14 days whereas cross-linked MatriDerm remained intact. No significant difference in wound contraction was found between scaffolds. In conclusion, cross-linked MatriDerm showed a significant increase in stability and strength, enhancing its durability and cell-scaffold interaction. in vivo analysis showed cross-linked MatriDerm had a reduced biodegradation rate with a similar host response. The extended structural integrity of cross-linked MatriDerm could potentially facilitate improved skin tissue regeneration, promoting the formation of a more pliable scar.

The impact of non-toxic blue light (453 nm) on cellular antioxidative capacity, TGF-β1 signaling, and myofibrogenesis of human skin fibroblasts

Studies have demonstrated that blue light induces biological effects, such as cell death, and inhibition of proliferation and differentiation. Since blue light at longer wavelength (>440 nm) exerts less injurious effects on cells than at shorter wavelengths, (400-440 nm), we have investigated the impact of non-toxic (LED) blue light at 453 nm wavelength on human skin fibroblasts (hsFBs). We found that besides its decreasing effects on the proliferation rate, repeated blue light irradiations (80 J/cm²) also significantly reduced TGF-β1-induced myofibrogenesis as shown by diminished α-SMA and EDA-FN expression accompanied by reduced protein expression and phosphorylation of ERK 1/2, SMAD 2/3, and p38-key players of TGF-β1-induced myofibrogenesis. In parallel, catalase protein expression, intracellular FAD concentrations as well as NADP⁺/NADPH ratio were reduced, whereas intracellular reactive oxygen species (ROS) were increased. We postulate that as a molecular mechanism downregulation of catalase and photoreduction of FAD induce intracellular oxidative stress which, in turn, affects the signaling factors of myofibrogenesis leading to a lower rate of α-SMA and EDA-FN expression and, therefore, myofibroblast formation. In conclusion, blue light even at longer wavelengths shows antifibrotic activity and may represent a suitable and safe approach in the treatment of fibrotic skin diseases including hypertrophic scarring and scleroderma.

Antifibrotic role of low-dose mitomycin-c-induced cellular senescence in trabeculectomy models

Purpose

We assessed whether mitomycin-C (MMC) has different antifibrotic mechanisms in trabeculectomy wound healing.

Methods

We identified 2 concentrations of MMC as “low-dose” by using WST-1 assay, Lactic dehydrogenase assay, and fluorescence-activated cell sorting flow cytometry. Senescence-associated β-galactosidase (SA-β-gal) and fibrotic gene expression was examined through immunocytochemistry, flow cytometry, real-time quantitative reverse transcription polymerase chain reaction, Western blotting, zymography, and modified scratch assay in vitro. In vivo, 0.1 mL of MMC or normal saline was injected to Tenon’s capsule before trabeculectomy in a rabbit model. SA-β-gal expression, apoptotic cell death, and collagen deposition in sites treated and not treated with MMC were evaluated using terminal dUTP nick end labeling assay and histochemical staining. Bleb function and intraocular pressure (IOP) levels were examined 3, 7, 14, 21, 28, and 35 days after trabeculectomy.

Results

In vitro, human Tenon’s fibroblast (HTF) senescence was confirmed by observing cell morphologic change, SA-β-gal accumulation, formation of senescence-associated heterochromatin, increased p16^INK4a and p21^CIP1/WAF1 expression, lower percentage of Ki-67-positive cells, and decreased COL1A1 release. Increased expression of α-SMA, COL1A1, and Smad2 signaling in TGF-β1-induced stress fibers were passivated in senescent HTFs. In addition, cellular migration enhanced by TGF-β1was inactivated. In vivo, histological examination indicated increased SA-β-gal accumulation, lower apoptosis ratios, and looser collagen deposition in sites treated with 0.2 μM MMC. Low-dose MMC-induced cellular senescence prolonged trabeculectomy bleb survival and reduced IOP levels in a rabbit model.

Conclusion

Low-dose MMC-induced cellular senescence is involved in the antifibrotic mechanism of trabeculectomy wound healing.

The Role of IL-6 in Skin Fibrosis and Cutaneous Wound Healing

The timely resolution of wound healing is critical for restoring the skin as a protective barrier. The switch from a proinflammatory to a reparative microenvironment must be tightly regulated. Interleukin (IL)-6 is a key modulator of the inflammatory and reparative process: it is involved in the differentiation, activation, and proliferation of leukocytes, endothelial cells, keratinocytes, and fibroblasts. This review examines the role of IL-6 in the healing of cutaneous wounds, and how dysregulation of IL-6 signaling can lead to either fibrosis or a failure to heal. The role of an IL-6/TGF-β feedback loop is discussed in the context of fibrogenesis, while IL-6 expression and responses in advanced age, diabetes, and obesity is outlined regarding the development of chronic wounds. Current research on therapies that modulate IL-6 is explored. Here, we consider IL-6′s diverse impact on cutaneous wound healing.

Differential Effects of Extracorporeal Shockwave Therapy and Botulinum Toxin-A Injection on Postburn Contractures and Gait Kinematics in Burn Children

Postburn contracture is a complex and multifactorial problem that requires intensive inputs from the burn care staff. This study endeavored to evaluate the effectiveness of extracorporeal shockwave therapy and botulinum toxin-A for treating the postburn plantar flexion contracture and optimizing ankle kinematics in burn children. Thirty-eight children with burns and plantar flexion contracture were randomized to receive the standard physical rehabilitation program (control group; n = 13), unfocused extracorporeal shockwave therapy (0.2 mJ/mm2) once a week over four consecutive weeks in addition to the standard physical rehabilitation (n = 12), or botulinum toxin-A injection (0.5–2 U/kg/muscle group with maximum dose of 12 U/kg/body weight) once at entry besides the standard physical rehabilitation (n = 13). Dorsiflexion active range of motion and ankle kinematics were measured before and immediately after treatment. The posttreatment dorsiflexion active range of motion increased significantly in the extracorporeal shockwave therapy group (P = .025) and botulinum toxin-A group (P = .04) when compared to the control group. Likewise, the initial stance–dorsiflexion, stance-maximum dorsiflexion, and swing-peak dorsiflexion angle improved significantly in the extracorporeal shockwave therapy group (P ˂ .001, P = .005, and P = .002, respectively) and botulinum toxin-A group (P = .004, P = .012, and P ˂ .001, respectively) compared to the control group. No significant differences were observed between the extracorporeal shockwave therapy and botulinum toxin-A groups with respect to any of the measured variables. To conclude, extracorporeal shockwave therapy and botulinum toxin-A injection could be effectively used to treat postburn plantar flexion contracture and to optimize the ankle kinematics during walking in children, without preference for either of them.

The combined effect of tranilast 8% liposomal gel on the final cosmesis of acne scarring in patients concomitantly treated by isotretinoin: prospective, double-blind, split-face study

BACKGROUND

Tranilast [N-(3,4-dimethoxycinnamoyl) anthranilic acid] has never been investigated for the prevention and treatment of acne scars.

AIM

To evaluate the efficacy and safety of tranilast 8% gel in improving the final appearance of patients with acne scarring concomitantly treated by isotretinoin.

METHODS

This was a prospective, double-blind, split-face study, which enrolled 40 otherwise healthy participants (aged 18-49 years) with facial acne scars. For each patient, one half of the face were treated with tranilast 8% liposomal gel and the other half with a water-based placebo. Using the Global Aesthetic Improvement Scale (GAIS), acne scars were evaluated by two dermatologists and by the patients, and the patients also rated their satisfaction with the treatment and reported adverse effects.

RESULTS

In total, 32 participants completed the trial. The mean GAIS scores at 5 months post-treatment were significantly lower (better outcome) for the tranilast-treated side than the placebo-treated areas in patients concomitantly treated with isotretinoin (P < 0.001). All the isotretinoin-treated patients reported greater satisfaction and better general improvement in the skin's appearance and texture, and also greater improvement of pigment and redness on the tranilast 8% gel-treated side compared with the control side.

CONCLUSION

Combined topical application of tranilast 8% gel twice daily with oral isotretinoin treatment in the active phase of acne vulgaris may result in fewer scars, finer skin texture and enhanced appearance.

[Deep alkali burns: Evaluation of a two-step surgical strategy]

INTRODUCTION

Chemical burns are rare but often lead to deep cutaneous lesions. Alkali agents have a deep and long lasting penetrating power, causing burns that evolve over several days. The local treatment for these patients is excision of the wound and split thickness skin graft. Early excision and immediate skin grafting of alkali burns are more likely to be complicated by graft failure and delayed wound healing. We propose a two-step method that delays skin grafting until two-three days after burn wound excision.

RESULTS

Our population included 25 controls and 16 cases. Men were predominant with a mean age of 41.9 years. In 78% of cases, burns were located on the lower limbs. The mean delay between the burn and excision was 16.5 days. In cases, the skin graft was performed at a mean of 11.3 days after the initial excision. We did not unveil any significant difference between both groups for the total skin surface affected, topography of the burns and the causal agent. Wound healing was significantly shorter in cases vs controls (37.5 days vs 50.3 days; P<0.025). Furthermore, we observed a decreased number of graft failures in cases vs controls (13.3% vs 46.7%; P=0.059).

CONCLUSION

Our study shows the relevance of a two-step surgical strategy in patients with alkali chemical burns. Early excision followed by interval skin grafting is associated with quicker wound healing and decreased rate of graft failure.

Cutaneous Scarring: Basic Science, Current Treatments, and Future Directions

Significance: Scarring of the skin from burns, surgery, and injury constitutes a major burden on the healthcare system. Patients affected by major scars, particularly children, suffer from long-term functional and psychological problems. Recent Advances: Scarring in humans is the end result of the wound healing process, which has evolved to rapidly repair injuries. Wound healing and scar formation are well described on the cellular and molecular levels, but truly effective molecular or cell-based antiscarring treatments still do not exist. Recent discoveries have clarified the role of skin stem cells and fibroblasts in the regeneration of injuries and formation of scar. Critical Issues: It will be important to show that new advances in the stem cell and fibroblast biology of scarring can be translated into therapies that prevent and reduce scarring in humans without major side effects. Future Directions: Novel therapies involving the use of purified human cells as well as agents that target specific cells and modulate the immune response to injury are currently undergoing testing. In the basic science realm, researchers continue to refine our understanding of the role that particular cell types play in the development of scar.

Potential role of propolis in wound healing: Biological properties and therapeutic activities

Propolis is a resinous mixture that honey bees collect from the tree buds, sap flows, or other botanical sources. The chemical composition of propolis varies and depends on the geographical area, time of collection, seasonality, illumination, altitude, and food availability during propolis exploitation. The goal of this review is to discuss important concepts including mechanisms of action and therapeutic activities of propolis. The PubMed, ScienceDirect, and Cochrane Library databases were searched for the literature published from January the 1st 2000 to October the 1st 2017. Sixteen animals and three clinical studies were included. A quantitative and qualitative review was performed on the clinical trials and the animal studies were comprehensively overviewed. In this study, the clinical trials have been combined and the results were provided as meta-analysis. Propolis is a non-toxic natural product; however some cases of allergy and contact dermatitis to this compound have been described mainly among beekeepers. An important factor in impaired wound healing is biofilm formation; propolis as an anti-microbial agent can reduce biofilm generation and result in accelerated healing processes. Most of the in vivo studies on various wound models suggested the beneficial roles of propolis on experimental wound healing and this has also been approved in the clinical trial studies. However, there is a lack of information concerning, dose, side effects and clinical effectiveness of propolis on wounds. As the effectiveness of propolis between different products is variable, more characterizations should be done and future investigations comparing different propolis based products and characterization of their specific roles on different models of wounds are highly appreciated.

The Effect of Tranilast 8% Liposomal Gel Versus Placebo on Post-Cesarean Surgical Scars: A Prospective Double-Blind Split-Scar Study

BACKGROUND

Tranilast (N-[3, 4-dimethoxycinnamoyl] anthranilic acid), an antiallergic drug, has been shown to attenuate scar formation possibly through inhibition of transforming growth factor beta 1 activity and consequent suppression of collagen synthesis in fibroblasts.

OBJECTIVE

The authors aimed at evaluating the efficacy and safety of tranilast 8% gel in improving the appearance and symptoms of new post-cesarean section surgical wounds.

METHODS

In this prospective double-blind split-scar study, the authors treated each half scar of 26 women with either tranilast 8% liposomal gel or tranilast-free liposomal gel (placebo). Treatment was applied twice daily for 3 months. Twenty women completed the trial. Scar halves were evaluated by 2 investigators and by the patients 9 months after the last application using the Patient and Observer Scar Assessment Scale (POSAS). The participants also rated overall satisfaction and recorded side effects of the treatment.

RESULTS

The mean POSAS scores at 9 months post-treatment were significantly lower for tranilast-treated half scars compared with placebo-treated half scars (p < .001). The women were significantly more satisfied with the tranilast-treated half-scar appearance (p = .002). Three participants reported itching and erythema on the tranilast-treated side.

CONCLUSION

Topical tranilast 8% gel provided significantly better postcaesarian section scar cosmesis and user satisfaction compared with placebo.

Biological Principles of Scar and Contracture

Hypertrophic scar and contracture in burn patients is a complex process. Contributing factors include critical injury depth and activation of key cell subpopulations, including deep dermal fibroblasts, myofibroblasts, fibrocytes, and T-helper cells, which cause scarring rather than regeneration. These cells influence each other via cellular profibrotic and antifibrotic signals, which help to determine the outcome. These cells also both modify and interact with extracellular matrix of the wound, ultimately forming hypertrophic scar. Current treatments reduce hypertrophic scar formation or improve remodeling by targeting these pathways and signals.

5-Aminolaevulinic Acid-Based Photodynamic Therapy Restrains Pathological Hyperplasia of Fibroblasts

Background

This study aimed to explore whether 5-aminolaevulinic acid-based photodynamic therapy (ALA-PDT) restrains pathological hyperplasia of fibroblasts from hyperplastic scar tissues, and to investigate the potential mechanism.

Material/Methods

We used MTT assay, flow cytometry, and terminal-deoxynucleotidyl transferase mediated nick-end labeling (TUNEL) to examine the effects of ALA-PDT on proliferation, cell cycle, and apoptosis of fibroblasts isolated from hyperplastic scar tissues. The growth-promoting effect of fibroblasts on vascular endothelial cells was measured by cell co-culture. Real-time PCR and Western blot analysis were performed to detect the expression levels of transforming growth factor-β1 (TGF-β1), α-smooth muscle actin (α-SMA), Collagen I, Collagen III, vascular endothelial growth factor-A (VEGFA), and basic fibroblast growth factor (bFGF).

Results

ALA-PDT inhibited proliferation delayed cell cycle progress, promoted apoptosis of fibroblasts, and suppressed its growth-promoting effect on vascular endothelial cells, and decreased expression of TGF-β1, α-SMA, Collagen I, Collagen III, VEGFA, and bFGF.

Conclusions

ALA-PDT effectively restrained pathological hyperplasia of fibroblasts from hyperplastic scar tissues, which may provide a research basis for clinical therapy of hyperplastic scars.

Secondary Interventions for Mutilating Hand Injuries

Care of the reconstructed hand following mutilating injury is akin to the care of a vintage car. Its mechanisms are delicate, spare parts are limited, touch-ups are required often, and a major overhaul is indicated rarely. Secondary interventions are indicated for completion of staged primary procedures, management of complications, targeted improvement of function, and enhancement of appearance of the reconstructed hand. The approach to secondary reconstruction depends on the patient's age, and vocational and recreational requirements. It is also influenced by the constant evolution of surgeons' reconstructive philosophy, experience, and technology.

Growth factor pathways in hypertrophic scars: Molecular pathogenesis and therapeutic implications

Hypertrophic scars represent the most common complication of skin injury and are caused by excessive cutaneous wound healing characterized by hypervascularity and pathological deposition of extracellular matrix (ECM) components. To date, the optimal and specific treatment methods for hypertrophic scars have not been available in the clinic. Current paradigm has established fibroblasts and myofibroblasts as pivotal effector cells in the pathophysiology of wound healing. Their biological properties including origin, proliferation, migration, contraction and ECM regulation have profound impacts on the progression and regression of hypertrophic scars. These complex processes are executed and modulated by a signaling network involving a number of growth factors and cytokines. Of particular importance is transforming growth factor-β, platelet-derived growth factor, connective tissue growth factor, epidermal growth factor, and vascular endothelial growth factor. This review article briefly describes the biological functions of fibroblasts and myofibroblasts during hypertrophic scars, and thereafter examines the up-to-date molecular knowledge on the roles of key growth factor pathways in the pathophysiology of hypertrophic scars. Importantly, the therapeutic implications and future challenges of these molecular discoveries are critically discussed in the hope of advancing therapeutic approaches to limit pathological scar formation.

Controlled water vapor transmission rate promotes wound-healing via wound re-epithelialization and contraction enhancement

A desirable microenvironment is essential for wound healing, in which an ideal moisture content is one of the most important factors. The fundamental function and requirement for wound dressings is to keep the wound at an optimal moisture. Here, we prepared serial polyurethane (PU) membrane dressings with graded water vapor transmission rates (WVTRs), and the optimal WVTR of the dressing for wound healing was identified by both in vitro and in vivo studies. It was found that the dressing with a WVTR of 2028.3 ± 237.8 g/m²·24 h was able to maintain an optimal moisture content for the proliferation and regular function of epidermal cells and fibroblasts in a three-dimensional culture model. Moreover, the dressing with this optimal WTVR was found to be able to promote wound healing in a mouse skin wound model. Our finds may be helpful in the design of wound dressing for wound regeneration in the future.

Potency of umbilical cord blood- and Wharton's jelly-derived mesenchymal stem cells for scarless wound healing

Postnatally, scars occur as a consequence of cutaneous wound healing. Scarless wound healing is highly desired for patients who have undergone surgery or trauma, especially to exposed areas. Based on the properties of mesenchymal stem cells (MSCs) for tissue repair and immunomodulation, we investigated the potential of MSCs for scarless wound healing. MSCs were expanded from umbilical cord blood (UCB-MSCs) and Wharton’s jelly (WJ-MSCs) from healthy donors who underwent elective full-term pregnancy caesarean sections. UCB-MSCs expressed lower levels of the pre-inflammatory cytokines IL1A and IL1B, but higher levels of the extracellular matrix (ECM)-degradation enzymes MMP1 and PLAU compared with WJ-MSCs, suggesting that UCB-MSCs were more likely to favor scarless wound healing. However, we failed to find significant benefits for stem cell therapy in improving wound healing and reducing collagen deposition following the direct injection of 1.0 × 10⁵ UCB-MSCs and WJ-MSCs into 5 mm full-thickness skin defect sites in nude mice. Interestingly, the implantation of UCB-MSCs tended to increase the expression of MMP2 and PLAU, two proteases involved in degradation of the extracellular matrix in the wound tissues. Based on our data, UCB-MSCs are more likely to be a favorable potential stem cell source for scarless wound healing, although a better experimental model is required for confirmation.

Effectiveness of wound healing using the novel collagen dermal substitute INSUREGRAF®

The pore structure of INSUREGRAF® built up from parallel collagen layers connected by single fivers and sizes are very uniform. Therefore, this is more suitable with respect to cell penetration, distribution, and acceleration of skin regeneration.

Non-Thermal Dielectric Barrier Discharge (DBD) Effects on Proliferation and Differentiation of Human Fibroblasts Are Primary Mediated by Hydrogen Peroxide

The proliferation of fibroblasts and myofibroblast differentiation are crucial in wound healing and wound closure. Impaired wound healing is often correlated with chronic bacterial contamination of the wound area. A new promising approach to overcome wound contamination, particularly infection with antibiotic-resistant pathogens, is the topical treatment with non-thermal “cold” atmospheric plasma (CAP). Dielectric barrier discharge (DBD) devices generate CAP containing active and reactive species, which have antibacterial effects but also may affect treated tissue/cells. Moreover, DBD treatment acidifies wound fluids and leads to an accumulation of hydrogen peroxide (H₂O₂) and nitric oxide products, such as nitrite and nitrate, in the wound. Thus, in this paper, we addressed the question of whether DBD-induced chemical changes may interfere with wound healing-relevant cell parameters such as viability, proliferation and myofibroblast differentiation of primary human fibroblasts. DBD treatment of 250 μl buffered saline (PBS) led to a treatment time-dependent acidification (pH 6.7; 300 s) and coincidently accumulation of nitrite (~300 μM), nitrate (~1 mM) and H₂O₂ (~200 μM). Fibroblast viability was reduced by single DBD treatments (60–300 s; ~77–66%) or exposure to freshly DBD-treated PBS (60–300 s; ~75–55%), accompanied by prolonged proliferation inhibition of the remaining cells. In addition, the total number of myofibroblasts was reduced, whereas in contrast, the myofibroblast frequency was significantly increased 12 days after DBD treatment or exposure to DBD-treated PBS. Control experiments mimicking DBD treatment indicate that plasma-generated H₂O₂ was mainly responsible for the decreased proliferation and differentiation, but not for DBD-induced toxicity. In conclusion, apart from antibacterial effects, DBD/CAP may mediate biological processes, for example, wound healing by accumulation of H₂O₂. Therefore, a clinical DBD treatment must be well-balanced in order to avoid possible unwanted side effects such as a delayed healing process.

Role of seaweed laminaran from Saccharina longicruris on matrix deposition during dermal tissue-engineered production

Our laboratory has developed a technique to reconstruct in vitro tissue from human cells using the self-assembly tissue-engineering method, which utilizes the ability of fibroblasts to deposit the matrix they secrete. The time necessary for tissue construction, several weeks, is a drawback for many clinical uses. We hypothesized that the addition of laminaran can increase the deposition of matrix, speeding up the production of the tissue. Laminaran was isolated from the brown seaweed Saccharina longicruris harvested in Canada and its structure was evaluated. Laminaran is a small molecular weight polysaccharide composed of linear glucose chains. Monolayer-cultured human skin fibroblasts were cultured in the presence of laminaran with ascorbate for 7 or 35 days to produce a dermis. Treatment did not induce any variation in the growth rate or alpha smooth muscle actin content but it did increase the deposition of collagen I in a dose-dependent manner. After 35 days, the reconstructed dermal thickness was increased when laminaran was added, and collagen I deposition and MMP activity were also significantly increased. Thus, laminaran can be used to increase the rate of production of reconstructed self-assembled dermis and can also potentially be used in cosmetic or therapeutic creams to stimulate matrix production.

Myofibroblast differentiation: main features, biomedical relevance, and the role of reactive oxygen species

SIGNIFICANCE

Myofibroblasts are prototypical fibrotic cells, which are involved in a number of more or less pathological conditions, from foreign body reactions to scarring, from liver, kidney, or lung fibrosis to neoplastic phenomena. The differentiation of precursor cells (not only of fibroblastic nature) is characterized by a complex interplay between soluble factors (growth factors such as transforming growth factor β1, reactive oxygen species [ROS]) and material properties (matrix stiffness).

RECENT ADVANCES

The last 15 years have seen very significant advances in the identification of appropriate differentiation markers, in the understanding of the differentiation mechanism, and above all, the involvement of ROS as causative and persistence factors.

CRITICAL ISSUES

The specific mechanisms of action of ROS remain largely unknown, although evidence suggests that both intracellular and extracellular phenomena play a role.

FUTURE DIRECTIONS

Approaches based on antioxidant (ROS-scavenging) principles and on the potentiation of nitric oxide signaling hold much promise in view of a pharmacological therapy of fibrotic phenomena. However, how to make the active principles available at the target sites is yet a largely neglected issue.

Distinct phenotype and therapeutic potential of gingival fibroblasts

Gingiva of the oral mucosa provides a practical source to isolate fibroblasts for therapeutic purposes because the tissue is easily accessible, tissue discards are common during routine clinical procedures and wound healing after biopsy is fast and results in complete wound regeneration with very little morbidity or scarring. In addition, gingival fibroblasts have unique traits, including neural crest origin, distinct gene expression and synthetic properties and potent immunomodulatory functions. These characteristics may provide advantages for certain therapeutic approaches over other more commonly used cells, including skin fibroblasts, both in intraoral and extra-oral sites. However, identity and phenotype of gingival fibroblasts, like other fibroblasts, are still not completely understood. Gingival fibroblasts are phenotypically heterogeneous, and these…fibroblast subpopulations may play different roles in tissue maintenance, regeneration and pathologies. The purpose of this review is to summarize what is currently known about gingival fibroblasts, their distinct potential for tissue regeneration and their potential therapeutic uses in the future.

Silibinin inhibits myofibroblast transdifferentiation in human tenon fibroblasts and reduces fibrosis in a rabbit trabeculectomy model

PURPOSE

To investigate the effect of silibinin in myofibroblast transdifferentiation and in animal trabeculectomy models.

METHODS

The effect of silibinin on the expression of α-smooth muscle actin (α-SMA) and vimentin in response to transforming growth factor-β1 (TGF-β1) was determined in human tenon fibroblasts (HTFs). Cell migration and collagen contraction arrays were used to demonstrate the functionality of silibinin-modulated HTFs. ELISA analysis was used to determine the effect of silibinin on the release of type 1 collagen and connective tissue growth factor (CTGF). The effect of silibinin on the activation of the TGF-β receptor-related pathway was evaluated by Western blotting. A rabbit model of trabeculectomy was established to assess the effect of silibinin in vivo.

RESULTS

TGF-β1 elevated the expression of α-SMA and vimentin in HTFs; this elevation was inhibited by silibinin. TGF-β1 increased cell migration and collagen contraction of HTFs, which were also suppressed by silibinin. The production of both CTGF and type 1 collagen in TGF-β1-treated HTFs was inhibited by silibinin. The effects of silibinin on TGF-β1-stimulated HTFs were mediated via the down-regulation of TGF-β receptor-related SMAD signalling pathways. In the rabbit model of trabeculectomy, silibinin increased the period of decreasing intraocular pressure after trabeculectomy and reduced the production of collagen and α-SMA at the site of blebs in vivo.

CONCLUSION

Silibinin inhibited the TGF-β receptor-related signalling pathway in TGF-β-treated HTFs and several of the downstream events associated with myofibroblast transdifferentiation. Silibinin also improved the outcome of trabeculectomies by reducing the fibrotic response in the bleb tissue in vivo.

[Early hypertrophic scar after surgery on the nasal region: value of long-acting corticosteroid injections]

BACKGROUND

"Pincushioning" is a complication of post-surgical scarring following use of transposition flaps particularly when surgery is performed on the nasal region. The transposition flap technique is very useful for the repair of certain defects of the tip of the nose, the medial canthus or of the ala nasi. The aim of this study is to define the clinical characteristics of this scarring dystrophy, which we propose to call "early hypertrophy scarring", to clarify the nature thereof and to assess the efficacy of intralesional injection of corticosteroids at the first signs of hypertrophy.

PATIENTS AND METHOD

A prospective, open, non-comparative, single-centre study examined the clinical and histological characteristics of early hypertrophy scarring and the effectiveness of therapy with one or two injections of corticosteroids performed on the 15th day post-operatively and optionally repeated at D45 depending on the outcome. From January 2011 to January 2013, 12 consecutive patients with early hypertrophy scarring were included (ten men and two women - mean age: 64 years). All had undergone surgery for basal cell carcinoma under local anaesthesia with one-stage repair by means of a rhombic flap or a bilobed flap located in the nasal area. Scars were injected strictly intra-lesionally with triamcinolone acetate (40 mg/1 mL) until whitening occurred. A single injection was performed in three cases of rhombic flap while a second injection was given at D45 in the remaining nine cases.

RESULTS

Complete regression of the early hypertrophy scarring was obtained in ten of the 12 patients by D90. Incomplete regression was observed but with a marked improvement in the other two patients.

DISCUSSION

Early hypertrophy scarring is distinguished by its clinical characteristics of hypertrophic or keloid scars. Biopsy performed in two cases showed the fibrous but non-fatty nature of early hypertrophy scarring. Biomechanical factors particular to the nasal region and the transposition flap technique could account for the early and excessive collagen production causing early hypertrophy scarring. Early injection of corticosteroids, which was consistently effective in our study, could represent a simple treatment for early hypertrophy scarring, thus avoiding surgical correction. These preliminary results in a small number of patients require confirmation by a comparative, multicentre, prospective controlled study.

The expression of α-SMA in the painful traumatic neuroma: potential role in the pathobiology of neuropathic pain

The exact mechanism of neuroma-associated pain is not yet fully understood, thus contributing to the substantial challenge faced in managing patients with painful neuromas. We aimed to observe the expression of alpha smooth muscle actin (α-SMA) in the painful traumatic neuroma and to investigate its possible roles in the cause of neuroma-associated pain. Its expression is considered to be a useful phenotypic marker for myofibroblast, and may contribute to its increased contractile activity. We collected peripheral neuroma specimens prospectively and subsequently divided them into two groups: painful (n=21) and non-painful (n=27) based on blinded preoperative visual analogue scale (VAS) pain scores. We also harvested normal nerve specimens from the discarded limbs as a control group (n=8). We performed immunohistological studies to observe the expression of α-SMA in each group, and calculated the expression level by a high-resolution pathological image analysis system. There was no positive staining of α-SMA observed in the control group, slight positive staining in the non-painful group, and obviously positive staining in the painful group. Pearson correlation analysis demonstrated that VAS scores were significantly associated with the expression intensity of α-SMA (R=0.831; p<0.001). Linear regression analysis indicated that the expression intensity of α-SMA was positively related to the scale of VAS (R(2)=0.691, p<0.001). These findings suggest that: 1) expression of α-SMA may play certain roles in painful traumatic neuroma, either as a direct cause of neuroma-associated pain or as an indirect marker of local mechanical stimuli, and 2) the presence of α-SMA in the painful group may provide rationale for transpositional procedures in the management of traumatic neuroma. The persistent existence of α-SMA in the painful group and the correlation with VAS scores may provide insight into the development of new therapeutic strategies.

Effects of zafirlukast on capsular contracture: long-term results

Capsular contracture is a distressing complication after breast augmentation for both the patient and surgeon. Although capsular contracture is a multifactorial process, one common denominator in the successful treatment of this complication is believed to be the abatement of inflammation. Leukotriene antagonists have recently emerged as effective prophylactic agents in reactive airway diseases. A prospective study was carried out on 60 female patients (120 prostheses implanted) with mild/severe capsular contracture in at least one breast. The hardness of capsular contracture was assessed by means of the mammary compliance method. Patients received zafirlukast (Accolate&#174;) for a 6-month period. Mammary compliance was assessed at the start of the study and thereafter monthly, during drug intake and for one year after drug withdrawal. The results show a significant decrease in breast compliance values in the first 6 months, followed by a significant increase one year after the end of drug intake. Indeed, zafirlukast-treated patients displayed a 6.93 percent reduction in mammary compliance after 1 month, 14.42 percent after 3 months, 22.05 percent after 6 months and 22.52 percent after 7 months (1 month after the withdrawal of the drug). Thereafter, mammary compliance values gradually increased. A 5.47 percent reduction in mammary compliance was observed 1 year after drug withdrawal. The present study suggests that zafirlukast may be effective in reducing breast capsule distortion in patients with long-standing contracture, though reduced capsular contracture values are strictly related to the duration of drug intake.

A biomechanical model of wound contraction and scar formation

We propose a biomechanical model for investigating wound contraction mechanism and resulting scarring. Extracellular matrix is modeled as fiber-reinforced anisotropic soft tissue, with its elastic properties dynamically changing with the density and orientation of collagen fibers. Collagen fibers are deposited by fibroblasts infiltrating the wound space, and are dynamically aligned with both migrating fibroblasts and tissue residing tension field. Our new 2D hybrid agent-based model provides a comprehensive platform for examining the mechanobiology in wound contraction and scar formation. Simulation results are consistent with experimental observations and are able to reveal the effects of wound morphology and mechanical environment on contraction patterns. Our model results support the hypothesis that scar formation is the product of collagen fiber synthesis and alignment in the presence of the tensile stress field generated by a wound contraction process.

Wnt/β-catenin pathway forms a negative feedback loop during TGF-β1 induced human normal skin fibroblast-to-myofibroblast transition

BACKGROUND

Fibroblast-to-myofibroblast transition is a key event during wound healing and hypertrophic scar formation. Previous studies suggested Wnt/β-catenin signaling might be involved in the wound healing. However, its specific role in skin fibroblast-to-myofibroblast transition remains unclear.

OBJECTIVE

To investigate the specific role of β-catenin during the transforming growth factor-β1 induced normal skin myofibroblasts transition.

METHODS

By real-time quantitative polymerase chain reaction, Western-blot and immunocytochemistry, the activation of Wnt/β-catenin pathway in cultured human normal skin fibroblasts during TGF-β1 induced fibroblast-to-myofibroblast transition was investigated. The effects of β-catenin on myofibroblasts transition were also investigated when SB-216763, over-expression and siRNA of β-catenin were utilized. In addition, fibroblasts populated collagen lattices contraction assays were conducted to examine the effects of β-catenin on the contractility of the fibroblasts induced by TGF-β1. Furthermore, the effects of β-catenin on the expression of α-smooth muscle actin and collagen types I and III in hypertrophic scar derived fibroblasts were studied.

RESULTS

The expression of Wnts mRNA and β-catenin protein was up-regulated by TGF-β1 stimulation during the myofibroblasts transition. Both of SB-216763 and β-catenin over-expression was paralleled with decreased expression of α-smooth muscle actin, collagen types I and III, while siRNA targeting β-catenin leads to up-regulation of α-smooth muscle actin, collagen types I and III. The increased contractility and α-smooth muscle actin expression of the fibroblasts in the collagen lattices induced by TGF-β1 was inhibited by SB-216763. In addition, the expression levels of α-smooth muscle actin, collagen types I and III in hypertrophic scar derived fibroblasts were also down-regulated by SB-216763.

CONCLUSION

Specifically in normal skin fibroblasts, β-catenin might be involved in the myofibroblasts transition and negatively regulate the TGF-β1-induced myofibroblast transition.

How to assess scar hypertrophy--a comparison of subjective scales and Spectrocutometry: a new objective method

Scar hypertrophy is a significant clinical problem involving both linear scars from elective surgery and scars caused by trauma or burns. The treatment of hypertrophic scars is often time consuming, and patients may need to be followed up for months or even years. The methods for reliable quantification of scar hypertrophy are at present unsatisfying. We have developed a new, objective method, Spectrocutometry, for documentation and quantification of scar hypertrophy. The instrument is based on standardized digital imaging and spectral modeling and calculates the estimated concentration change of hemoglobin and melanin from the entire scar and also provides standardized images for documentation. Three plastic surgeons have assessed 37 scars from melanoma surgery using Spectrocutometry, the Vancouver scar scale, and the patient and observer scar assessment scale. The intraclass correlation coefficient for the Vancouver scar scale and the patient and observer scar assessment scale was lower than required for reliable assessment (r=0.66 and 0.60, respectively). The intraclass correlation coefficient for Spectrocutometry was high (r=0.89 and 0.88). A Bayesian network analysis revealed a strong dependency between the estimated concentration change of hemoglobin and scar pain. Spectrocutometry is a feasible method for measuring scar hypertrophy. It is shown to be more reliable than subjective rating in assessing linear surgical scars.