Advances in the Modulation of Cutaneous Wound Healing and Scarring

Inorganic nanoparticle-based nanogels and their biomedical applications

The advent of nanotechnology has brought tremendous progress in the field of biomedical science and opened avenues for advanced diagnostics and therapeutics applications. Several nanocarriers such as nanoparticles, liposomes, and nanogels have been designed to increase the drug efficiency and targeting ability in patients. Nanoparticles based on gold, silver, and iron are dominantly used for biomedical purposes owing to their biocompatibility properties. Nanoparticles offer an enhanced permeation into tissue vessels; however, their short half-life, toxicity, and off-site accumulations limit their functionality. The above shortcomings could be prevented by employing an integrated system combining nanoparticles with a nanogel-based system. These nanogels are 3D polymeric networks formed by physical and chemical crosslinking and are capable of incorporating nanoparticles, drugs, proteins, and genetic materials. Modification, functionalization, and introduction of inorganic nanoparticles have been shown to enhance the properties of nanogels, such as biocompatibility, stimuli responsiveness, stability, and selectivity. This review paper is focused on the design, synthesis, and biomedical application of inorganic nanoparticle-based nanogels. Current challenges and future perspectives will be briefly discussed to emphasize the versatile role of these multifunctional nanogels for therapeutic and diagnostic purposes.

Familial Spontaneous Keloids: Examining Thoracic Manifestations in Two Brothers

Keloids are complex fibroproliferative disorders with diverse clinical presentations. Spontaneous keloids (SKs) represent a rare subtype that emerges without any known preceding traumatic event. This report presents a case of familial spontaneous keloids appearing on the thoracic region in two brothers with no prior history of trauma or keloid occurrence in other family members. The lesions exhibited progressive growth over several years but responded to cycles of triamcinolone treatment. This case underscores an unusual spontaneous occurrence of keloids in the thoracic region of two siblings, highlighting the potential genetic predisposition in the aetiology of these lesions. Additionally, this instance reinforces the concept that keloids can develop spontaneously without any apparent trauma in the affected area.

Unveiling the mechanisms for the development of rosehip-based dermatological products: an updated review

Rosa spp., commonly known as rosehips, are wild plants that have traditionally been employed as herbal remedies for the treatment of a wide range of disorders. Rosehip is a storehouse of vitamins, including A, B complex, C, and E. Among phytonutrients, vitamin C is found in the highest amount. As rosehips contain significant levels of vitamin C, they are perfect candidates for the development of skincare formulations that can be effectively used in the treatment of different skin disorders (i.e., scarring, anti-aging, hyperpigmentation, wrinkles, melasma, and atopic dermatitis). This research focuses on the vitamin C content of several Rosa sp. by their botanical and geographic origins, which according to research studies are in the following order: R. rugosa > R. montana > R. canina > R. dumalis, with lower levels in R. villosa and R. arvensis, respectively. Among rosehip species, R. canina is the most extensively studied species which also displays significant amounts of bioactive compounds, but also antioxidant, and antimicrobial activities (e.g., against Propionibacterium acnes, Staphylococcus aureus, S, epidermis, and S. haemolyticus). The investigation also highlights the use of rosehip extracts and oils to minimise the harmful effects of acne, which primarily affects teenagers in terms of their physical appearance (e.g., scarring, hyperpigmentation, imperfections), as well as their moral character (e.g., low self-confidence, bullying). Additionally, for higher vitamin C content from various rosehip species, the traditional (i.e., infusion, maceration, Soxhlet extraction) and contemporary extraction methods (i.e., supercritical fluid extraction, microwave-assisted, ultrasonic-assisted, and enzyme-assisted extractions) are highlighted, finally choosing the best extraction method for increased bioactive compounds, with emphasis on vitamin C content. Consequently, the current research focuses on assessing the potential of rosehip extracts as medicinal agents against various skin conditions, and the use of rosehip concentrations in skincare formulations (such as toner, serum, lotion, and sunscreen). Up-to-date studies have revealed that rosehip extracts are perfect candidates as topical application products in the form of nanoemulsions. Extensive in vivo studies have revealed that rosehip extracts also exhibit specific activities against multiple skin disorders (i.e., wound healing, collagen synthesis, atopic dermatitis, melasma, and anti-aging effects). Overall, with multiple dermatological actions and efficacies, rosehip extracts and oils are promising agents that require a thorough investigation of their functioning processes to enable their safe use in the skincare industry.

Post-operative KEloids iRradiation (POKER): does the surgery/high-dose interventional radiotherapy association make a winning hand?

PURPOSE

To report the results involving post-operative interventional radiotherapy (POIRT) in a homogenous cohort of patients affected by keloid and treated at a single institution with the same fractionation schedule.

PATIENTS AND METHODS

Inclusion criteria were: surgery with a histopathological diagnosis of keloid, subsequent high-dose rate interventional radiotherapy (HDR-IRT)-12 Gy in 4 fractions (3 Gy/fr) twice a day-and follow-up period ≥ 24 months.

RESULTS

One-hundred and two patients and a total of 135 keloids were eligible for the analyses. Median follow-up was 64 [IQR: 25-103] months. Thirty-six (26.7%) recurrences were observed, 12-months and 36-months cumulative incidence of recurrence were 20.7% (95% CI 12.2-28.5) and 23.8% (95% CI 14.9-31.7) respectively. History of spontaneous keloids (HR = 7.00, 95% CI 2.79-17.6, p < 0.001), spontaneous cheloid as keloid cause (HR = 6.97, 95% CI 2.05-23.7, p = 0.002) and sternal (HR = 10.6, 95% CI 3.08-36.8, p < 0.001), ear (HR = 6.03, 95% CI 1.71-21.3, p = 0.005) or limb (HR = 18.8, 95% CI 5.14-68.7, p < 0.001) keloid sites were significantly associated to a higher risk of recurrence.

CONCLUSIONS

The findings support the use of surgery and POIRT as an effective strategy for controlling keloid relapses. Further studies should focus on determining the optimal Biologically Effective Dose and on establishing a scoring system for patient selection.

Pressure-garment therapy for preventing hypertrophic scarring after burn injury

BACKGROUND

Burn damage to skin often results in scarring; however in some individuals the failure of normal wound-healing processes results in excessive scar tissue formation, termed 'hypertrophic scarring'. The most commonly used method for the prevention and treatment of hypertrophic scarring is pressure-garment therapy (PGT). PGT is considered standard care globally; however, there is continued uncertainty around its effectiveness.

OBJECTIVES

To evaluate the benefits and harms of pressure-garment therapy for the prevention of hypertrophic scarring after burn injury.

SEARCH METHODS

We used standard, extensive Cochrane search methods. We searched CENTRAL, MEDLINE, Embase, two other databases, and two trials registers on 8 June 2023 with reference checking, citation searching, and contact with study authors to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing PGT (alone or in combination with other scar-management therapies) with scar management therapies not including PGT, or comparing different PGT pressures or different types of PGT.

DATA COLLECTION AND ANALYSIS

At least two review authors independently selected trials for inclusion using predetermined inclusion criteria, extracted data, and assessed risk of bias using the Cochrane RoB 1 tool. We assessed the certainty of evidence using GRADE.

MAIN RESULTS

We included 15 studies in this review (1179 participants), 14 of which (1057 participants) presented useable data. The sample size of included studies ranged from 17 to 159 participants. Most studies included both adults and children. Eight studies compared a pressure garment (with or without another scar management therapy) with scar management therapy alone, five studies compared the same pressure garment at a higher pressure versus a lower pressure, and two studies compared two different types of pressure garments. Studies used a variety of pressure garments (e.g. in-house manufactured or a commercial brand). Types of scar management therapies included were lanolin massage, topical silicone gel, silicone sheet/dressing, and heparin sodium ointment. Meta-analysis was not possible as there was significant clinical and methodological heterogeneity between studies. Main outcome measures were scar improvement assessed using the Vancouver Scar Scale (VSS) or the Patient and Observer Scar Assessment Scale (POSAS) (or both), pain, pruritus, quality of life, adverse events, and adherence to therapy. Studies additionally reported a further 14 outcomes, mostly individual scar parameters, some of which contributed to global scores on the VSS or POSAS. The amount of evidence for each individual outcome was limited. Most studies had a short follow-up, which may have affected results as the full effect of any therapy on scar healing may not be seen until around 18 months. PGT versus no treatment/lanolin We included five studies (378 participants). The evidence is very uncertain on whether PGT improves scars as assessed by the VSS compared with no treatment/lanolin. The evidence is also very uncertain for pain, pruritus, adverse events, and adherence. No study used the POSAS or assessed quality of life. One additional study (122 participants) did not report useable data. PGT versus silicone We included three studies (359 participants). The evidence is very uncertain on the effect of PGT compared with silicone, as assessed by the VSS and POSAS. The evidence is also very uncertain for pain, pruritus, quality of life, adverse events, adherence, and other scar parameters. It is possible that silicone may result in fewer adverse events or better adherence compared with PGT but this was also based on very low-certainty evidence. PGT plus silicone versus no treatment/lanolin We included two studies (200 participants). The evidence is very uncertain on whether PGT plus silicone improves scars as assessed by the VSS compared with no treatment/lanolin. The evidence is also very uncertain for pain, pruritus, and adverse events. No study used the POSAS or assessed quality of life or adherence. PGT plus silicone versus silicone We included three studies (359 participants). The evidence is very uncertain on the effect of PGT plus silicone compared with silicone, as assessed by the VSS and POSAS. The evidence is also very uncertain for pain, pruritus, quality of life, adverse events, and adherence. PGT plus scar management therapy including silicone versus scar management therapy including silicone We included one study (88 participants). The evidence is very uncertain on the effect of PGT plus scar management therapy including silicone versus scar management therapy including silicone, as assessed by the VSS and POSAS. The evidence is also very uncertain for pain, pruritus, quality of life, adverse events, and adherence. High-pressure versus low-pressure garments We included five studies (262 participants). The evidence is very uncertain on the effect of high pressure versus low pressure PGT on adverse events and adherence. No study used the VSS or the POSAS or assessed pain, pruritus, or quality of life. Different types of PGT (Caroskin Tricot + an adhesive silicone gel sheet versus Gecko Nanoplast (silicone gel bandage)) We included one study (60 participants). The evidence is very uncertain on the effect of Caroskin Tricot versus Gecko Nanoplast on the POSAS, pain, pruritus, and adverse events. The study did not use the VSS or assess quality of life or adherence. Different types of pressure garments (Jobst versus Tubigrip) We included one study (110 participants). The evidence is very uncertain on the adherence to either Jobst or Tubigrip. This study did not report any other outcomes.

AUTHORS' CONCLUSIONS

There is insufficient evidence to recommend using either PGT or an alternative for preventing hypertrophic scarring after burn injury. PGT is already commonly used in practice and it is possible that continuing to do so may provide some benefit to some people. However, until more evidence becomes available, it may be appropriate to allow patient preference to guide therapy.

Liposomes and transferosomes in the delivery of papain for the treatment of keloids and hypertrophic scars

Hypertrophic scars and keloids are characterized by an excessive collagen deposition. The available treatment options are invasive and can result in recurrence of scar formation. Using liposomes and transferosomes for the topical delivery of papain, a proteolytic enzyme, can be effective treatment. The objective of the study is to formulate papain-loaded liposomes and transferosomes, characterize the formulations, and study in vitro permeation using shed snake skin and Sprague-Dawley rat skin as models for stratum corneum and full thickness skin. Papain-loaded liposomes and transferosomes were formulated using the thin-film hydration method for the delivery of papain across the stratum corneum barrier. An in vitro permeation study carried out using shed-snake skin and Sprague-Dawley rat skin models showed that transferosomes were able to deliver papain across the stratum corneum barrier, while papain solution and papain liposomes were not able to cross the barrier. However, transferosomes were not able to deliver papain across the full thickness rat skin model suggesting the deposition of papain loaded transferosomes in the epidermal or dermal layer of skin. In addition, an ex-vivo model was used to analyze the effect of papain exposure on the morphology of the epidermis taken from rat skin exposed to papain solution, papain in transferosomes and papain in liposomes. Papain in solution resulted in a noticeable degradation of the epidermis, but when embedded in either transferosomes or liposomes there was no noticeable change when compared to control animals. The cytotoxicity study performed using HeLa cells showed that the cells were viable at papain concentrations lower than 0.01 mg/ml.

Needle-free electronically controlled jet injection with corticosteroids in recalcitrant keloid scars: a retrospective study and patient survey

First-line treatment of keloids consists of intralesional needle injections with corticosteroids, but generally entails multiple painful sessions, resulting in variable clinical outcomes. Novel needle-free jet injectors may facilitate more effective and patient-friendly dermal drug delivery. Here, we evaluated the effectiveness, tolerability and patient satisfaction of intralesional triamcinolone-acetonide (TCA) treatment in recalcitrant keloids using an electronically controlled pneumatic injector (EPI). A retrospective study was conducted in recalcitrant keloid patients with a history of severe pain during needle injections who received three sessions of EPI + TCA. Outcome measures included Patient and Observer Scar Assessment Scale (POSAS), Global Aesthetic Improvement Scale (GAIS), treatment-related pain (NRS), adverse effects, and patient satisfaction (survey). Ten patients with in total 283 keloids were included. The POSAS score significantly improved at follow-up and GAIS was reported as '(very) improved' for all patients. EPI + TCA was well-tolerated with a significantly lower NRS pain score compared to needle + TCA (pilot treatment). Only minor adverse effects occurred, and 90% of patients preferred EPI over needle treatment. EPI + TCA is an effective and tolerable treatment for patients with recalcitrant keloids. The minimal treatment-related pain and high patient satisfaction makes it a promising treatment for patients with needle-phobia and/or severe pain during needle injections.

Influence of Moisturizers on Skin Microcirculation: An Assessment Study Using Laser Speckle Contrast Imaging

Non-invasive scar management typically involves pressure therapy, hydration with silicones or moisturizers, and UV protection. Moisture loss from scars can lead to hypertrophic scar formation. Pressure therapy reduces blood flow, fibroblast activity, and transforming growth factor beta 1 (TGF-β1) release. This study examined various moisturizers and liquid silicone gel's impact on microcirculation. 40 volunteers participated in a study where superficial abrasions were created to induce trans epidermal water loss (TEWL). Five moisturizers (TEDRA®, TEDRA® NT1, TEDRA® NT3, Alhydran®, Lipikar®) and BAP Scar Care® silicone gel were tested. TEWL, hydration, and blood flow were measured up to 4 h post-application. Results showed that silicone had the least impact on occlusion and hydration. Alhydran® reduced blood flow the most, while Lipikar® increased it the most. TEDRA® NT1 had reduced flow compared to TEDRA® and TEDRA® NT3. All TEDRA® products exhibited high hydration, and all but silicone showed good occlusion. Moisturizers influenced skin microcirculation, with some causing decrease, while others increased flow. However, the clinical impact on scarring remains unclear compared to the evident effects of hydration and occlusion. More research is necessary to study moisturizers alone and with pressure therapy on scars, along with potential adverse effects of increased microcirculation on scars.

Pressure therapy for scars: Myth or reality? A systematic review

BACKGROUND

Hypertrophic scarring is a deviate occurrence after wound closure and is a common burn sequela. The mainstay of scar treatment consists of a trifold approach: hydration, UV-protection and the use of pressure garments with or without extra paddings or inlays to provide additional pressure. Pressure therapy has been reported to induce a state of hypoxia and to reduce the expression pattern of transforming growth factor-β1 (TGF-β1), therefore limiting the activity of fibroblasts. However, pressure therapy is said to be largely based on empirical evidence and a lot of controversy concerning the effectiveness still prevails. Many variables influencing its effectivity, such as adherence to treatment, wear time, wash frequency, number of available pressure garment sets and amount of pressure remain only partially understood. This systematic review aims to give a complete and comprehensive overview of the currently available clinical evidence of pressure therapy.

METHODS

A systematic search for articles concerning the use of pressure therapy in the treatment and prevention of scars was performed in 3 different databases (Pubmed, Embase, and Cochrane library) according to the PRISMA statement. Only case series, case-control studies, cohort studies, and RCTs were included. The qualitative assessment was done by 2 separate reviewers with the appropriate quality assessment tools.

RESULTS

The search yielded 1458 articles. After deduplication and removal of ineligible records, 1280 records were screened on title and abstract. Full text screening was done for 23 articles and ultimately 17 articles were included. Comparisons between pressure or no pressure, low vs high pressure, short vs long duration and early vs late start of treatment were investigated.

CONCLUSION

There is sufficient evidence that indicates the value of prophylactic and curative use of pressure therapy for scar management. The evidence suggests that pressure therapy is capable of improving scar color, thickness, pain, and scar quality in general. Evidence also recommends commencing pressure therapy prior to 2 months after injury, and using a minimal pressure of 20-25 mmHg. To be effective, treatment duration should be at least 12 months and even preferably up to 18-24 months. These findings were in line with the best evidence statement by Sharp et al. (2016).

The Effects of Chitosan on the Healing Process of Oral Mucosa: An Observational Cohort Feasibility Split-Mouth Study

The healing process is a dynamic process accompanied by some classical symptoms of inflammation such as redness, swelling, pain, and loss of function. Chitosan is a natural polymer with properties that contribute to tissue healing, with properties that could be applied in periodontal therapy, such as the wound healing of oral mucosa. This experimental split-mouth study aims to assess the possibilities of chitosan influencing the healing process of oral mucosa in eight patients, where the studied group was subjected to two oral surgeries: one with chitosan hydrogel into the socket and other without the biomaterial. A semi-quantitative analysis of the data was performed. Some classic signs of inflammation in a short period of time were observed where chitosan acted, compared to the control. An absence of bleeding was observed in the chitosan cases. According to the literature, chitosan recruits and activates neutrophils and macrophages and stimulates angiogenesis. Hemostatic and antimicrobial activity of chitosan also play an important role in wound healing. Chitosan seems to improve the postoperative quality of patients, allowing rapid wound healing with less complications.

Recent advancement of nanotherapeutics in accelerating chronic wound healing process for surgical wounds and diabetic ulcers

One of the greatest challenges faced during surgical procedures is closing and healing of wounds, which are essential in the field of orthopaedics, trauma, intensive care and general surgery. One of the main causes of death has been linked to chronic wounds, especially in immunosuppressant or diabetic patients. Due to increasing chronic wound fatality along with different pathologies associated with them, the current therapeutic methods are insufficient which has established an eminent need for innovative techniques. Traditionally, wound healing was carried out using formulations and ointments containing silver combined with different biomaterial, but was found to be toxic. Hence, the advent of alternative nanomaterial-based therapeutics for effective wound healing have come into existence. In this review, we have discussed an overview of wound infections such as different wound types, the wound healing process, dressing of wounds and conventional therapies. Furthermore, we have explored various nanotechnological advances made in wound healing therapy which include the use of promising candidates such as organic, inorganic, hybrid nanoparticles/nanocomposites and synthetic/natural polymer-based nanofibers. This review further highlights nanomaterial-based applications for regeneration of tissue in wound healing and can provide a base for researchers worldwide to contribute to this advancing medical area of wound therapy.

Analysis of the Utility of CO2 and Pulse-Dye Lasers Together and Separately in the Treatment of Hypertrophic Burn Scars

INTRODUCTION

Hypertrophic burn scars (HTBSs) remain a significant source of morbidity. Contemporary treatment has evolved to use CO2 lasers and/or pulse-dye lasers (PDLs) to reduce scar thickness (ST) and erythema. This study seeks to compare treatment efficacy with CO2 or PDL individually and in combination.

METHODS

Patients undergoing laser treatments for HTBSs were enrolled. Three 3 × 3 cm squares of HTBSs were randomized to receive treatment with CO2 laser, PDL or CO2 + PDL. Patients underwent 3 treatments, 4 to 6 weeks apart and were followed up over 3 to 6 months. Scar assessments occurred at each visit before treatment and consisted of photographs, ultrasound, colorimetry, and the Patient and Observer Scar Assessment Score.

RESULTS

Twenty-five patients were enrolled. Twenty completed 2 treatments (80%) and 11 completed all 3 treatments (44%). Median initial ST was 0.3 cm. Median time since injury was 8 months. Hypertrophic burn scars treated with CO2 or PDL showed a significant decrease in Patient and Observer Scar Assessment Scale score from visit 1 to 3 (P = 0.01 and 0.01, respectively). When separated by ST, thick scars (≥0.3 cm) showed a significant decrease in thickness between visit 1 and 2 using all laser modalities (CO2 + PDL, P = 0.01; CO2, P = 0.02; PDL, P = 0.03). Thin scars (<0.3 cm) showed a reduction in thickness by visit 3 after CO2 + PDL or PDL alone (P = 0.01 and 0.04, respectively). Separating scars by age, younger scars (<9 months) showed a significant reduction in thickness between visit 1 and 2 for CO2 treatment (P = 0.04), and between visit 2 and 3 for CO2 + PDL treatment (P = 0.04). Hypertrophic burn scars treated with PDL did not demonstrate a significant reduction in thickness until visit 3 (P = 0.002). Older scars (≥9 months) showed a significant reduction in thickness between visit 1 and 2 only after CO2 + PDL (P = 0.01).

CONCLUSIONS

Hypertrophic burn scars of varying ages, etiologies, and thicknesses were examined in this study with greater degree of early reduction seen in thicker scars using all laser modalities of CO2, PDL or in combination. However, there was no clinically meaningful benefit found with combination as compared with individual treatment. These data support the use of laser to improve HTBS but does not support one modality or combination of modalities over another.

V-EMF treatment of facial scar: First results

AIM OF STUDY

This is a retrospective study aimed at evaluating the effectiveness of the use of electromagnetic fields and negative pressure treatment (V-EMF) for facial scars, from an aesthetic and functional point of view, and considering the variations in the levels of hydration.

MATERIAL AND METHODS

25 subjects with facial scarring were re-evaluated after being treated with the V-EMF method. The hydration levels of the scars before and after treatment were compared. The results were evaluated considering the satisfaction levels of the patients with the VAS, and of the medical specialists who performed the treatment, and of 3 independent dermatologists with the Likert scale.

RESULTS

Mean hydration levels of scars went from 41.8 to 53.3, with mean hydration levels of healthy reference points equal to 54.6. The minimum patient satisfaction level was 2 in the VAS. The minimum level of satisfaction of specialists and dermatologists was equal to IV on the Likert scale for all patients, except for 1 subject in which it was III for the specialist who had treated him. Anti-aging and re-pigmentation effects were also noted as secondary results.

CONCLUSIONS

From an aesthetic and functional point of view, and for the overall anti-aging effect of the treated area, V-EMF applied to facial scars has shown extremely promising results.

Scar Perception: A Comparison of African American and White Self-identified Patients

Scars can have significant morbidity and negatively impact psychological, functional, and cosmetic outcomes as well as the overall quality-of-life, especially among ethnic minorities. The objective of this study was to evaluate African American and White patients' perception of their scars' impact on symptoms, appearance, psychosocial health, career, and sexual well-being, using validated assessment tools.

Method

A total of 675 abdominoplasty and breast surgery patients from four providers completed the SCAR-Q, and Career/Sexual Well-Being scales via phone or email. A higher score on both assessments indicates a more positive patient perception.

Results

Of the 675 respondents, 77.0% were White, and 23.0% were African American. White patients scored significantly higher on the SCAR-Q (232 ± 79 versus 203 ± 116), appearance (66 ± 26 versus 55 ± 29), and Career/Sexual Well-Being (16 ± 2 versus 15 ± 5) scales than African American patients (P < 0.001, P < 0.001, P < 0.001, respectively). There was no significant correlation between duration after surgery and symptoms or appearance scores for African American patients (P = 0.11, P = 0.37). There was no significant correlation between patient age and SCAR-Q score or time after surgery and psychosocial scores.

Conclusions

African American patients are more likely to have lower perceptions of their scarring appearance, symptoms, psychosocial impact, career impact, and sexual well-being impact than White patients. Scar appearance and symptoms are less likely to improve over time for African American patients. This study highlights the need to address patient ethnicity when considering further follow-up, counseling, or other measures to enhance scar perception.

Treatment of keloids and hypertrophic scars. Position statement of the Brazilian expert group GREMCIQ

Keloids (K) and hypertrophic scars (HS) are abnormal responses to wound healing that occur as the result of dermal inflammation. Despite the advances on their treatment, many patients still suffer from the negative effects of excessive scarring; its approach is impaired by the lack of objective data on different treatments and the large genetic variability among patients and the difficulties in producing multicentre studies. Their incidence among the Brazilian population is high, as the result of an admixture of Amerindians, Europeans and Africans ancestral roots. With the aim of producing multicentre studies on K and HS, a panel of senior Brazilian dermatologists focused on their treatment was invited to contribute with the K and HS Treatment Brazilian Guidelines. In the first part of this study, different treatment modalities for keloids and HS are fully reviewed by the panel. The second part of the study presents a consensus recommendation of treatment for different types of lesions. More than a literature review, this article aims to show the pitfalls and pearls of each therapeutic option, as well as a therapeutic approach by the Panel of Experts on keloids and Scars on a highly mixed population, providing simple guidelines.

Keratinocyte Growth Factor-based Strategies for Wound Re-epithelialization

Wound re-epithelialization is a dynamic process that comprises the formation of new epithelium through an active signaling network between several growth factors and various cell types. The main players are keratinocytes that migrate from the wound edges onto the wound bed, to restore the epidermal barrier. One of the most important molecules involved in the re-epithelialization process is Keratinocyte Growth Factor (KGF), since it is central on promoting both migration and proliferation of keratinocytes. Stromal cells, like dermal fibroblasts, are the main producers of this factor, acting on keratinocytes through paracrine signaling. Multiple therapeutic strategies to delivery KGF have been proposed in order to boost wound healing by targeting re-epithelialization. This has been achieved through a range of different approaches, such as topical application, using controlled release-based methods with different biomaterials (hydrogels, nanoparticles and membranes) and also through gene therapy techniques. Among these strategies, KGF delivery via biomaterials and genetic-based strategies show great effectiveness in sustained KGF levels at the wound site, leading to efficient wound closure. Under this scope, this review aims at highlighting the importance of KGF as one of the key molecules on wound re-epithelialization, as well as to provide a critical overview of the different potential therapeutic strategies exploited so far.

Scar-Free Healing: Current Concepts and Future Perspectives

Every year, millions of people develop scars due to skin injuries after trauma, surgery, or skin burns. From the beginning of wound healing development, scar hyperplasia, and prolonged healing time in wound healing have been severe problems. Based on the difference between adult and fetal wound healing processes, many promising therapies have been developed to decrease scar formation in skin wounds. Currently, there is no good or reliable therapy to cure or prevent scar formation. This work briefly reviews the engineering methods of scarless wound healing, focusing on regenerative biomaterials and different cytokines, growth factors, and extracellular components in regenerative wound healing to minimize skin damage cell types, and scar formation.

Nonsurgical Management of Hypertrophic Scars: Evidence-Based Therapies, Standard Practices, and Emerging Methods

Hypertrophic scars, resulting from alterations in the normal processes of cutaneous wound healing, are characterized by proliferation of dermal tissue with excessive deposition of fibroblast-derived extracellular matrix proteins, especially collagen, over long periods, and by persistent inflammation and fibrosis. Hypertrophic scars are among the most common and frustrating problems after injury. As current aesthetic surgical techniques become more standardized and results more predictable, a fine scar may be the demarcating line between acceptable and unacceptable aesthetic results. However, hypertrophic scars remain notoriously difficult to eradicate because of the high recurrence rates and the incidence of side effects associated with available treatment methods. This review explores the various treatment methods for hypertrophic scarring described in the literature including evidence-based therapies, standard practices, and emerging methods, attempting to distinguish those with clearly proven efficiency from anecdotal reports about therapies of doubtful benefits while trying to differentiate between prophylactic measures and actual treatment methods. Unfortunately, the distinction between hypertrophic scar treatments and keloid treatments is not obvious in most reports, making it difficult to assess the efficacy of hypertrophic scar treatment.

Gene Expression Profile of Isolated Dermal Vascular Endothelial Cells in Keloids

Wound healing is a complex biological process, and imbalances of various substances in the wound environment may prolong healing and lead to excessive scarring. Keloid is abnormal proliferation of scar tissue beyond the original wound margins with excessive deposition of extracellular matrix (ECM) and chronic inflammation. Despite numerous previous research efforts, the pathogenesis of keloid remains unknown. Vascular endothelial cells (VECs) are a major type of inductive cell in inflammation and fibrosis. Despite several studies on vascular morphology in keloid formation, there has been no functional analysis of the role of VECs. In the present study, we isolated living VECs from keloid tissues and investigated gene expression patterns using microarray analysis. We obtained 5 keloid tissue samples and 6 normal skin samples from patients without keloid. Immediately after excision, tissue samples were gently minced and living cells were isolated. Magnetic-activated cell sorting of VECs was performed by negative selection of fibroblasts and CD45⁺ cells and by positive selection of CD31⁺cells. After RNA extraction, gene expression analysis was performed to compare VECs isolated from keloid tissue (KVECs) with VECs from normal skin (NVECs). After cell isolation, the percentage of CD31⁺ cells as measured by flow cytometry ranged from 81.8%–98.6%. Principal component analysis was used to identify distinct molecular phenotypes in KVECs versus NVECs and these were divided into two subgroups. In total, 15 genes were upregulated, and 3 genes were downregulated in KVECs compared with NVECs using the t-test (< 0.05). Quantitative RT-PCR and immunohistochemistry showed 16-fold and 11-fold overexpression of SERPINA3 and LAMC2, respectively. SERPINA3 encodes the serine protease inhibitor, α1-antichymotripsin. Laminin γ2-Chain (LAMC2) is a subunit of laminin-5 that induces retraction of vascular endothelial cells and enhances vascular permeability. This is the first report of VEC isolation and gene expression analysis in keloid tissue. Our data suggest that SERPINA3 and LAMC2 upregulation in KVECs may contribute to the development of fibrosis and prolonged inflammation in keloid. Further functional investigation of these genes will help clarify the mechanisms of abnormal scar tissue proliferation.

Where do you insert a drain tube during breast reconstruction?

PURPOSE

A drain tube is commonly inserted during breast reconstruction surgery. This leads to a scar in addition to the scar on the breast. This study was performed to investigate how patients feel about the drain scar and to clarify its ideal location.

METHODS

A questionnaire survey about the drain scar was distributed to 38 consecutive breast reconstruction patients and a total of 104 female doctors and nurses engaged in breast reconstruction. The drain scars were evaluated using the Japan Scar Workshop (JSW) Scar Scale.

RESULTS

A total of 32% of the patients expressed some anxiety about the drain scar. Patients who were anxious about the drain scar had higher scores on the JSW Scar Scale than those who were not anxious. Younger doctors and nurses preferred the drain scar to be on the side of the chest, while older doctors and nurses preferred the drain scars to be at the axilla.

CONCLUSIONS

About a third of the patients had some anxiety associated with their drain scar after breast reconstruction surgery, and this anxiety level was correlated with objective assessment of the scar. Thus, more patient involvement or the provision of more information regarding drain placement is required.

Fractional CO2 laser ablation of porcine burn scars after grafting: Is deeper better?

INTRODUCTION

Fractional CO₂ lasers have been used in clinical settings to improve scarring following burn injury. Though used with increasing frequency, the appropriate laser settings are not well defined and overall efficacy of this therapy has not been definitively established. As it has been proposed that for thick hypertrophic scars proportionally greater fluence and thus deeper ablation into the scar tissue would be most effective, the goal of this study was to examine the role of ablation depth on scar outcomes in a highly-controlled porcine model for burn scars-after grafting.

METHODS

Properties of laser ablated wells were quantified on ex vivo pig skin as a function of laser energy (20, 70 or 150mJ). Full-thickness burn wounds were created on the dorsum of red Duroc pigs with the eschar excised and grafted with a split-thickness autograft meshed and expanded 1.5:1. After four weeks of healing, sites were treated with either 20, 70, or 150mJ pulse energy from a fractional CO₂ laser at 5% density or left untreated as a control. Sites were treated every four weeks with three total sessions. Scar area, pigmentation, erythema, roughness, histology, and biomechanics were evaluated prior to each laser treatment at day 28, 56, and 83, as well as four weeks after the final laser treatment, day 112. Additional biopsies were collected at day 112 for gene expression analysis.

RESULTS

The depth of the laser ablated wells increased with increasing pulse energy while the width of the wells was smaller in the 20mJ group and not significantly different in the 70 and 150mJ groups. Scar properties (area, color, biomechanics) were not significantly altered by laser therapy at any of the laser energies tested versus controls. Average scar roughness was improved by laser therapy in a dose dependent manner with scars treated with 150mJ of energy having the smoothest surface; however, these changes were not statistically significant. Assessment of matrix metalloproteinase 9 gene expression showed a slight upregulation in scars treated with 70 or 150mJ versus control scars and scars treated with 20mJ pulse energy.

CONCLUSION

The current study demonstrated that the properties of the ablative well (depth and width) are not linearly correlated with laser pulse energy, with only a small increase in well depth at energies between 70 and 150mJ. Overall, the study suggests that there is little difference in outcomes as a function of laser energy. Fractional CO₂ laser therapy did not result in any statistically significant benefit to scar properties assessed by quantitative, objective measures, thus highlighting the need for additional clinical investigation of laser therapy efficacy with non-treated controls and objective measures of outcome.

Nanomaterials for Wound Healing and Infection Control

Wound healing has been intensely studied in order to develop an "ideal" technique that achieves expeditious recovery and reduces scarring to the minimum, thus ensuring function preservation. The classic approach to wound management is represented by topical treatments, such as antibacterial or colloidal agents, in order to prevent infection and promote a proper wound-healing process. Nanotechnology studies submicroscopic particles (maximum diameter of 100 nm), as well as correlated phenomena. Metal nanoparticles (e.g., silver, gold, zinc) are increasingly being used in dermatology, due to their beneficial effect on accelerating wound healing, as well as treating and preventing bacterial infections. Other benefits include: ease of use, less frequent dressing changes and a constantly moist wound environment. This review highlights recent findings regarding nanoparticle application in wound management.

Optimization of reaction conditions to fabricate Ocimum sanctum synthesized silver nanoparticles and its application to nano-gel systems for burn wounds

The present study deals with sequential optimization strategy based on Box-Behnken method to optimize the process variables for efficient production of Ocimum sanctum synthesized silver nanoparticles using biological synthesis. Four substantial factors influencing the dependent variables viz size, zeta potential, Polydispersity index (PDI) and yield were identified as silver nitrate concentration, temperature, amount of plant extract and stirring speed as independent variables. The contribution of the studied factors in monitoring dependent variables was evaluated via analysis of variance. The validity of the model developed was verified, and the statistical analysis showed that the optimal operational conditions were AgNO₃ concentration 5.29 mM, temperature 60 °C, agitation speed of 500 rpm and plant extract 2.24% (w/v) which primes to form silver nanoparticles of smallest size 83.41 nm and 0.24 with maximum zeta potential of -20.20mV and Yield of 18.62. In addition, the optimized AgNPs were characterized using DLS, TEM, FE-SEM and UV-vis analysis. The topical formulation was prepared by incorporation of optimized AgNPs into the carbopol gel base. Further, the gel was evaluated in vivo using the rat model of skin wound healing. The measurement of the wound areas was performed on 2nd, 4th, 6th, 8th, 10th, 12th and 14th days and the percentage of wound closures were calculated accordingly. By the 14th day, silver nanoparticle gel showed 96.20% wound healing activity compared with that of the standard as well as control base. The antibacterial inhibitory efficiency of prepared nano gel was found similar to the commercial product against the Staphylococcus aureus, E. coli and Pseudomonas aeruginosa.

The application of W-plasty combined Botox-A injection in treating sunk scar on the face

This study was aimed to explore the effect of W-plasty combined Botox-A injection in improving appearance of scar.According to the inclusive and exclusive criteria, patients received W-plasty combined Botox-A injection (study group) or traditional (control group) scar repairment were enrolled in this study. After surgery, a follow-up ranged from 1 to 2 years was conducted. The effectiveness of surgery was assessed by visual analogue scale (VAS).A total of 38 patients were enrolled in this study, including 21 cases in the study group and 17 cases in the control group. There were no significant difference were identified in age (t = 0.339, P = .736), gender ratio (χ = 0.003, P = .955) and scar forming reason (χ = 0.391, P = .822) between 2 groups. After treatment, the VAS score in the study group was significantly higher than that in the control group (P < .001).W-plasty combined Botox-A injection can significantly improve the appearance of sunk scar on the face.

Adaptive and Pathological Reshuffling in the Venous Wall in Special Hemodynamic Conditions-Acquired Arteriovenous Fistula

Hemodialysis and peritoneal dialysis are the two possible choices in chronic renal disease in the uremic stage. Native arteriovenous fistula is susceptible to complications, some posing vital risk and requiring prompt treatment. We present the case of a patient undergoing hemodialysis on native AVF. An aneurism developed progressively on the arterialized cephalic vein. The AVF was abolished by closing the arteriotomy with a venous patch and excising the aneurismal venous segment. The pathology exam of the surgical specimen showed unequal vessel wall thickness due to hyperplasia of the media and subintimal space, with calcifications within the hyperplastic media.

Case Presentation of Soft Tissue Defect after Bimalleolar Fracture Osteosynthesis

A 59-year-old patient presented in the ER with wound dehiscence and skin necrosis on the right ankle, with osteosynthesis implant visible, after open reduction and fixation with plate and screws, performed abroad, 16 days prior to the presentation, for a bimalleolar fracture. The patient was admitted to the plastic surgery department, where surgical debridement of the necrotic tissue was initially performed. Postoperatively, the patient was treated with Negative-pressure wound therapy (VAC dressing) and Platelet rich plasma (PRP) therapy. Upon obtaining granulation tissue without signs of infection, a sural fasciocutaneous flap was performed to cover the skin defect. Proper graft integration and healing was observed.

Simultaneous silencing of TGF-β1 and COX-2 reduces human skin hypertrophic scar through activation of fibroblast apoptosis

Excessive skin scars due to elective operations or trauma represent a challenging clinical problem. Pathophysiology of hypertrophic scars entails a prolonged inflammatory and proliferative phase of wound healing. Over expression of TGF-β1 and COX-2 play key regulatory roles of the aberrant fibrogenic responses and proinflammatory mediators. When we silenced TGF-β1 and COX-2 expression simultaneously in primary human fibroblasts, a marked increase in the apoptotic cell population occurred in contrast to those only treated with either TGF-β1 or COX-2 siRNA alone. Furthermore, using human hypertrophic scar and skin graft implant models in mice, we observed significant size reductions of the implanted tissues following intra-scar administration of TGF-β1/COX-2 specific siRNA combination packaged with Histidine Lysine Polymer (HKP). Gene expression analyses of those treated tissues revealed silencing of the target gene along with down regulations of pro-fibrotic factors such as α-SMA, hydroxyproline acid, Collagen 1 and Collagen 3. Using TUNEL assay detection, we found that the human fibroblasts in the implanted tissues treated with the TGF-β1/COX-2_siRNAs combination exhibited significant apoptotic activity. Therefore we conclude that a synergistic effect of the TGF-β1/COX-2siRNAs combination contributed to the size reductions of the hypertrophic scar implants, through activation of fibroblast apoptosis and re-balancing between scar tissue deposition and degradation.

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.

Knockout of Angiotensin AT2 receptors accelerates healing but impairs quality

Wounds are among the most common, painful, debilitating and costly conditions in older adults. Disruption of the angiotensin type 1 receptors (AT₁R), has been associated with impaired wound healing, suggesting a critical role for AT₁R in this repair process. Biological functions of angiotensin type 2 receptors (AT₂R) are less studied. We investigated effects of genetically disrupting AT₂R on rate and quality of wound healing. Our results suggest that AT₂R effects on rate of wound closure depends on the phase of wound healing. We observed delayed healing during early phase of wound healing (inflammation). An accelerated healing rate was seen during later stages (proliferation and remodeling). By day 12, fifty percent of AT₂R^−/− mice had complete wound closure as compared to none in either C57/BL6 or AT₁R^−/− mice. There was a significant increase in AT₁R, TGFβ₁ and TGFβ₂ expression during the proliferative and remodeling phases in AT₂R^−/− mice. Despite the accelerated closure rate, AT₂R^−/− mice had more fragile healed skin. Our results suggest that in the absence of AT₂R, wound healing rate is accelerated, but yielded worse skin quality. Elucidating the contribution of both of the angiotensin receptors may help fine tune future intervention aimed at wound repair in older individuals.

The molecular basis of hypertrophic scars

Hypertrophic scars (HTS) are caused by dermal injuries such as trauma and burns to the deep dermis, which are red, raised, itchy and painful. They can cause cosmetic disfigurement or contractures if craniofacial areas or mobile region of the skin are affected. Abnormal wound healing with more extracellular matrix deposition than degradation will result in HTS formation. This review will introduce the physiology of wound healing, dermal HTS formation, treatment and difference with keloids in the skin, and it also review the current advance of molecular basis of HTS including the involvement of cytokines, growth factors, and macrophages via chemokine pathway, to bring insights for future prevention and treatment of HTS.

High-efficiency expression of TAT-bFGF fusion protein in Escherichia coli and the effect on hypertrophic scar tissue

Background

Basic fibroblast growth factor (bFGF) is a member of the fibroblast growth factor family that has effects on wounding healing and neuro-protection. However, it is difficult to use bFGF to treat diseases that are separated by physiological barriers, such as the dermal barrier and blood brain barrier.

Methodology/Principal Findings

To improve bFGF’s penetration ability, we fused the recombinant human fibroblast growth factor (rhbFGF) gene with TAT. We constructed a pET3c vector that contained the recombinant bFGF gene and successfully expressed this gene in the E. coli strain BL21 (DE3) pLsS. The fusion protein was purified using CM Sepharose FF and heparin affinity chromatography. The purity of the TAT-rhbFGF was greater than 95%, as detected by SDS-PAGE. An in vitro MTT trial revealed that the modified bFGF significantly promoted the proliferation of NIH3T3 cells. The cell penetration trial and the mouse skin penetration trial demonstrated that the fusion protein had certain penetration abilities. The animal experiments confirmed that TAT-rhbFGF was effective in the treatment of the hypertrophic scars.

Conclusions/Significance

We have successfully expressed and purified a TAT-rhbFGF fusion protein in this study. Our results have shown that the fusion protein had a greater ability to penetrate the dermal skin layer. TAT-rhbFGF improved the physical appearance of hypertrophic scars. TAT-rhbFGF may be a potential fusion protein in the treatment of dermal disorders, including hypertrophic scar.

Hydration status regulates sodium flux and inflammatory pathways through epithelial sodium channel (ENaC) in the skin

Although it is known that the inflammatory response that results from disruption of epithelial barrier function after injury results in excessive scarring, the upstream signals remain unknown. It has also been observed that epithelial disruption results in reduced hydration status and that the use of occlusive dressings that prevent water loss from wounds decreases scar formation. We hypothesized that hydration status changes sodium homeostasis and induces sodium flux in keratinocytes, which result in activation of pathways responsible for keratinocyte-fibroblast signaling and ultimately lead to activation of fibroblasts. Here, we demonstrate that perturbations in epithelial barrier function lead to increased sodium flux in keratinocytes. We identified that sodium flux in keratinocytes is mediated by epithelial sodium channels (ENaCs) and causes increased secretion of proinflammatory cytokines, which activate fibroblast via the cyclooxygenase 2 (COX-2)/prostaglandin E2 (PGE2) pathway. Similar changes in signal transduction and sodium flux occur by increased sodium concentration, which simulates reduced hydration, in the media in epithelial cultures or human ex vivo skin cultures. Blockade of ENaC, prostaglandin synthesis, or PGE2 receptors all reduce markers of fibroblast activation and collagen synthesis. In addition, employing a validated in vivo excessive scar model in the rabbit ear, we demonstrate that utilization of either an ENaC blocker or a COX-2 inhibitor results in a marked reduction in scarring. Other experiments demonstrate that the activation of COX-2 in response to increased sodium flux is mediated through the PIK3/Akt pathway. Our results indicate that ENaC responds to small changes in sodium concentration with inflammatory mediators and suggest that the ENaC pathway is a potential target for a strategy to prevent fibrosis.

Update on hypertrophic scar treatment

Scar formation is a consequence of the wound healing process that occurs when body tissues are damaged by a physical injury. Hypertrophic scars and keloids are pathological scars resulting from abnormal responses to trauma and can be itchy and painful, causing serious functional and cosmetic disability. The current review will focus on the definition of hypertrophic scars, distinguishing them from keloids and on the various methods for treating hypertrophic scarring that have been described in the literature, including treatments with clearly proven efficiency and therapies with doubtful benefits. Numerous methods have been described for the treatment of abnormal scars, but to date, the optimal treatment method has not been established. This review will explore the differences between different types of nonsurgical management of hypertrophic scars, focusing on the indications, uses, mechanisms of action, associations and efficacies of the following therapies: silicone, pressure garments, onion extract, intralesional corticoid injections and bleomycin.

A novel function for kojic acid, a secondary metabolite from Aspergillus fungi, as antileishmanial agent

Kojic acid (KA) is a fungal metabolite used as a topical treatment skin-whitening cosmetic agent for melasma in humans; however its potential as an anti-leishmanial agent is unknown. Chemotherapy is one of the most effective treatments for Leishmaniasis. However, the drugs available are expensive, invasive, require long-term treatment and have severe side effects. Thus, the development of new effective leishmanicidal agents is a necessity. In this study we investigated the anti-leishmanial effect of KA on L. amazonensis, following in vitro and in vivo infections. KA (50 μg/mL) was found to decrease the growth by 62% (IC₅₀ 34 μg/mL) and 79% (IC₅₀ 27.84 μg/mL) of promastigotes and amastigotes in vitro, respectively. Ultrastructural analysis of KA-treated amastigotes showed the presence of vesicles bodies into the flagellar pocket, and an intense intracellular vacuolization and swelling of the mitochondrion. During the in vitro interaction of parasites and the host cell, KA reverses the superoxide anions (O₂^-) inhibitory mechanism promoted by parasite. In addition, 4 weeks after KA-topical formulation treatment of infected animals, a healing process was observed with a high production of collagen fibers and a decrease in parasite burden. Thus, these results demonstrated the great potential of KA as an anti-leishmanial compound.

Dermal templates and the wound-healing paradigm: the promise of tissue regeneration

Dermal regeneration templates arguably represent the first and most clinically successful 'tissue engineering' solution designed for organ reconstruction. Wound healing in the skin normally occurs on a continuum. At one extreme of the continuum lies the promise of tissue regeneration and the complete restoration of normal structure and function. Unfortunately, in the adult, all too often, wound healing occurs at the other extreme of the continuum and the dermis is reconstituted as scar tissue. Dermal regeneration templates are designed to manage the wound-healing process and tip the scales toward regeneration. This review discusses the architecture and molecular composition of the skin and the events that mediate wound healing and scar formation. The development, evolution and commercialization of dermal templates are examined and the clinical and business considerations that drive the product-development cycle are discussed. In the near term, dermal templates cannot be expected to dramatically change in overall composition. Product development will be dominated by continued refinements of existing templates and the field of use will continue to expand as manufacturers seek to increase revenue and capture market share. Continued exploration of novel processing strategies, such as electrospinning, that can be used to fabricate nanoscale biomaterials, may provide a gateway to the next generation of dermal templates.

Keloids and hypertrophic scars: update and future directions

Summary:

The development of cutaneous pathological scars, namely, hypertrophic scars (HSs) and keloids, involves complex pathways, and the exact mechanisms by which they are initiated, evolved, and regulated remain to be fully elucidated. The generally held concepts that keloids and HSs represent “aberrant wound healing” or that they are “characterized by hyalinized collagen bundles” have done little to promote their accurate clinicopathological classification or to stimulate research into the specific causes of these scars and effective preventative therapies. To overcome this barrier, we review here the most recent findings regarding the pathology and pathogenesis of keloids and HSs. The aberrations of HSs and keloids in terms of the inflammation, proliferation, and remodeling phases of the wound healing process are described. In particular, the significant roles that the extracellular matrix and the epidermal and dermal layers of skin play in scar pathogenesis are examined. Finally, the current hypotheses of pathological scar etiology that should be tested by basic and clinical investigators are detailed. Therapies that have been found to be effective are described, including several that evolved directly from the aforementioned etiology hypotheses. A better understanding of pathological scar etiology and manifestations will improve the clinical and histopathological classification and treatment of these important lesions.

The molecular mechanism of hypertrophic scar

Hypertrophic scar (HTS) is a dermal form of fibroproliferative disorder which often develops after thermal or traumatic injury to the deep regions of the skin and is characterized by excessive deposition and alterations in morphology of collagen and other extracellular matrix (ECM) proteins. HTS are cosmetically disfiguring and can cause functional problems that often recur despite surgical attempts to remove or improve the scars. In this review, the roles of various fibrotic and anti-fibrotic molecules are discussed in order to improve our understanding of the molecular mechanism of the pathogenesis of HTS. These molecules include growth factors, cytokines, ECM molecules, and proteolytic enzymes. By exploring the mechanisms of this form of dermal fibrosis, we seek to provide some insight into this form of dermal fibrosis that may allow clinicians to improve treatment and prevention in the future.

The healing and anti-scar effects of astragaloside IV on the wound repair in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Astragaloside IV is the chief ingredient of Radix Astragali, which has been used in the Traditional Chinese Medicine as a major component of many polyherbal formulations for the repair and regeneration of injured organ and tissues. This study is to investigate the influence of astragaloside IV on both of the wound healing and scar formation.

MATERIALS AND METHODS

For the in vitro evaluation, the influence of the astragaloside IV in the wound scratch test of keratinocytes and the secretion of transforming growth factor-β1, a key factor contributing to scar formation were determined. With the rat skin excision model, the in vivo regulation of astragaloside IV on wound closure, angiogenesis and collagen disposition were also evaluated.

RESULTS

Astragaloside IV was shown to significantly promote the migration of keratinocytes in wound scratching assay. The superior effect of Astragaloside IV was observed at 100 μmol/L, in which the recover rates was increased with 2 and 3 folds after 48 h and 96 h respectively than that of blank control (P<0.01). Animal skin closure measurement showed that astragaloside IV could stimulate the wound healing, e.g. with 21% recover in contrast to the 8% of blank control at the 6th day. Biomechanic and Masson's trichrome stain analysis indicated that astragaloside IV may improve the strength of the repaired skin and promoted the angiogenesis and collagen synthesis. Meanwhile, the picrosirius-sirus red stain and Elisa test definitely showed the anti-scar effects of astragaloside IV by decreasing the levels of collagen I/III and TGF-β1 secretion by firbroblasts with a dose-dependent manner (25-100 μmol/L).

CONCLUSIONS

Astragaloside IV was shown a promising natural product with both healing and anti-scar effects for wound treatment. These results give the evidence for the application of astragaloside IV in the treatment of injury.