Fibroproliferative scars

Drug suspending during wound healing effectively weakens immunosuppression-related complications by preserving CD8+ T cell function

Immunosuppressive medications, which interfere with the activation and proliferation of T and B cells, increase the risk of wound healing complications. To address it, this study aimed to validate the feasibility of drug suspending during wound healing, whilst exploring the mechanisms exerted by T cells, which are important in the wound healing process. For this, a mouse skin wound model was set up. Tacrolimus (FK506) and fingolimod (FTY720) were both administered intraperitoneally prior to wounding to inhibit the T cell activation and migration, respectively. Flow-cytometric analysis subsequently revealed the functional T cell subtypes detected during the healing process. A CD8a antibody was also administered to deplete CD8+ T cells in vivo to verify their specific function. It was found that FK506 or FTY720 administration delayed the early phase of wound healing by reducing collagen production, which was also supported by the downregulation of col1a1, col3a1 and tgfb1. However, there was no significant difference in the total healing period. Both spleen- and skin-derived CD8+ T cells were proliferated and activated after injury without intervention, whereas CD4+ T cells showed no significant changes. Furthermore, selectively depleting CD8+ T cells retarded the healing process by downregulating collagen production-associated genes (col1a1, col3a1, tgfβ1 and en1) and proteins (collagen type 1 and 3). In addition, the CD8a antibody decreased the expression of genes lta, tnfa, il13 and il13ra, and protein interleukin-13Rα. In conclusion, suspending immunosuppressive drugs during wound healing was shown to be feasible through restraining the migration of activated T cells. CD8+ T cells represented the primary functional subtype positively associated with wound healing.

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.

Assessment of various intralesional injections in keloid: Comparative analysis

AIM

Intralesional triamcinolone is a gold standard in treating the keloids to comparation its effectiveness versus intralesional 5-fluorouracil intralesional verapamil and intralesional platelet-rich plasma.

PATIENTS AND METHODS

Several 160-cases were categorized into four groups of each Group-Containing 40 cases. Group-A (control) treated with intralesional triamcinolone and Group-B intralesional verapamil, Group-C intralesional 5-fluorouracil, and Group-D intralesional platelet-rich plasma. Patients were assessed for clinical response based on a decrease in the patient and observer scar assessment scale (POSAS) at baseline and the end of treatment.

RESULTS

The mean base-line POSAS score was 91 ± 10.98 SD check-in Group-A, 90 ± 10.85 in Group-B, 89 ± 10.06 in Group-C, and 92 ± 10.84 in Group-D.POSAS score after 24 weeks 36 ± 12.74 in Group-A, 29 ± 10.91 in Group-B, 39 ± 13.74 in Group-C, 36 ± 12.74 in Group-D. Statistically, a significant difference was observed between groups.

CONCLUSION

Intralesional verapamil reported to be the most effective therapy and platelet-rich plasma was effective as intralesional triamcinolone acetonide with no serious side effects and 5-fluorouracil was less effective in treating the keloids.

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.

Extracellular matrix gene expression during arm regeneration in Amphiura filiformis

Extracellular matrix (ECM) plays a dynamic role during tissue development and re-growth. Body part regeneration efficiency relies also on effective ECM remodelling and deposition. Among invertebrates, echinoderms are well known for their striking regenerative abilities since they can rapidly regenerate functioning complex structures. To gather insights on the involvement of ECM during arm regeneration, the brittle star Amphiura filiformis was chosen as experimental model. Eight ECM genes were identified and cloned, and their spatio-temporal and quantitative expression patterns were analysed by means of whole mount in situ hybridisation and quantitative PCR on early and advanced regenerative stages. Our results show that almost none of the selected ECM genes are expressed at early stages of regeneration, suggesting a delay in their activation that may be responsible for the high regeneration efficiency of these animals, as described for other echinoderms and in contrast to most vertebrates. Moreover, at advanced stages, these genes are spatially and temporally differentially expressed, suggesting that the molecular regulation of ECM deposition/remodelling varies throughout the regenerative process. Phylogenetic analyses of the identified collagen-like genes reveal complex evolutionary dynamics with many rounds of duplications and losses and pinpointed their homologues in selected vertebrates. The study of other ECM genes will allow a better understanding of ECM contribution to brittle star arm regeneration.

Anti-miR-200b promotes wound healing by regulating fibroblast functions in a novel mouse model

MicroRNA-200b (miR-200b) down-regulation has been found in wound-healing tissues. Fibroblasts are the predominant cells that orchestrate the production of collagen in wound healing. However, it is still unclear whether miR-200b can affect the wound healing by regulating the fibroblasts' function. The current rodent wound-healing models are not ideal due to their marked difference in structure compared with the human skin. In this study, we demonstrated that the murine plantar skin had similar anatomical features to the human skin. Using this model, the gain/loss-of-function studies showed that miR-200b caused a significantly delayed wound healing in vivo. Furthermore, using cell proliferation, migration and collagen synthesis assays, we found that miR-200b attenuated cell proliferation, migration and collagen synthesis of fibroblasts, which are critical aspects of wound healing. miR-200b also decreased the expression of Zeb1. Collectively, we established a new murine plantar skin model for the investigation of wound healing, and based on it we found that miR-200b affected the wound healing by regulating the biological function of fibroblasts, which provided a new insight for wound healing.

Triamcinolone acetonide intralesional injection for the treatment of keloid scars: patient selection and perspectives

Keloids are pathological scars presenting as nodular lesions that extend beyond the area of injury. They do not spontaneously regress, often continuing to grow over time. The abnormal wound-healing process underlying keloid formation results from the lack of control mechanisms self-regulating cell proliferation and tissue repair. Keloids may lead to cosmetic disfigurement and functional impairment and affect the quality of life. Although several treatments were reported in the literature, no universally effective therapy was found to date. The most common approach is intralesional corticosteroid injection alone or in combination with other treatment modalities. Triamcinolone acetonide (TAC) is the most commonly used intralesional corticosteroid. The aim of this article was to review the use of TAC, alone or in combination, in the treatment of keloid scars. The response to corticosteroid injection alone is variable with 50-100% regression and a recurrence rate of 33% and 50% after 1 and 5 years, respectively. Compared to verapamil, TAC showed a faster and more effective response even though with a higher complication rate. TAC combined with verapamil was proved to be effective with statistically significant overall improvements of scars over time and long-term stable results. TAC and 5-fluorouracil (5-FU) intralesional injections were found to achieve comparable outcomes when administered alone, although 5-FU was more frequently associated with side effects. Conversely, the combination of 5-FU and TAC was more effective and showed fewer undesirable effects compared to TAC or 5-FU alone. Several kinds of laser treatments were reported to address keloids; however, laser therapy alone was burdened with a high recurrence rate. Better results were described by combining CO2, pulsed-dye or Nd: YAG lasers with TAC intralesional injections. Further options such as needle-less intraepidermal drug delivery are being explored, but more studies are needed to establish safety, feasibility and effectiveness of this approach.

Fundamental aspects of arm repair phase in two echinoderm models

Regeneration is a post-embryonic developmental process that ensures complete morphological and functional restoration of lost body parts. The repair phase is a key step for the effectiveness of the subsequent regenerative process: in vertebrates, efficient re-epithelialisation, rapid inflammatory/immune response and post-injury tissue remodelling are fundamental aspects for the success of this phase, their impairment leading to an inhibition or total prevention of regeneration. Among deuterostomes, echinoderms display a unique combination of striking regenerative abilities and diversity of useful experimental models, although still largely unexplored. Therefore, the brittle star Amphiura filiformis and the starfish Echinaster sepositus were here used to comparatively investigate the main repair phase events after injury as well as the presence and expression of immune system and extracellular matrix (i.e. collagen) molecules using both microscopy and molecular tools. Our results showed that emergency reaction and re-epithelialisation are similar in both echinoderm models, being faster and more effective than in mammals. Moreover, in comparison to the latter, both echinoderms showed delayed and less abundant collagen deposition at the wound site (absence of fibrosis). The gene expression patterns of molecules related to the immune response, such as Ese-fib-like (starfishes) and Afi-ficolin (brittle stars), were described for the first time during echinoderm regeneration providing promising starting points to investigate the immune system role in these regeneration models. Overall, the similarities in repair events and timing within the echinoderms and the differences with what has been reported in mammals suggest that effective repair processes in echinoderms play an important role for their subsequent ability to regenerate. Targeted molecular and functional analyses will shed light on the evolution of these abilities in the deuterostomian lineage.

The effects of a topical gel containing chitosan, 0,2% chlorhexidine, allantoin and despanthenol on the wound healing process subsequent to impacted lower third molar extraction

BACKGROUND

Despite efforts to prevent postoperative discomfort, there are still many immediate side effects associated with the surgical extraction of impacted lower third molars. Cicatrization is a physiological process through which the loss of integrity of oral mucosa is recovered and damaged tissues are repaired. Bexident Post (ISDIN, Spain) is a topical gel that contains chitosan, 0.2% chlorhexidine, allantoin and dexpanthenol. While this gel has many clinical indications, there are no published clinical trials evaluating its use in impacted mandibular third molar surgery. This study aims to clinically evaluate the efficacy of a gel containing chitosan, 0.2% chlorhexidine, allantoin and dexpanthenol on wound healing and reduction of postoperative side effects and complications after extraction of an impacted mandibular third molar.

MATERIAL AND METHODS

A split-mouth design study was carried out on a total of 50 bilaterally and symmetrically impacted third molar extractions, which were randomly placed into either a control group (CG=25) or an experimental group (EG=25). Patients were all informed of the purpose of the study and provided written consent. All procedures were carried out by the same dental practitioner, in accordance with standard surgical protocol. A different dental practitioner, unaware of which treatment had been applied, provided follow-up care. The EG applied 10 ml of topical gel composed of chitosan, 0.2% chlorhexidine, allantoin and dexpanthenol to the surgical wound three times a day for 10 days, patients in the CG did not apply any gel.

RESULTS

The groups were homogeneous insofar as potentially confounding variables. No significant findings were found regarding postoperative swelling and pain. Neither of the groups displayed poor healing or infectious complications of the wound during the postoperative period. In all the recorded follow-ups (Day 7 p=0.001, and Day 14 p=0.01), the wound's aesthetic appearance was better in the EG. Overall treatment tolerance was satisfactory and similar in both groups.

CONCLUSIONS

The gel composed of chitosan, 0.2% chlorhexidine, allantoin and dexpanthenol did not aid in patients' postoperative comfort; however, improved wound healing was observed.

Wound repair during arm regeneration in the red starfish Echinaster sepositus

Starfish can regenerate entire arms following their loss by both autotomic and traumatic amputation. Although the overall regenerative process has been studied several times in different asteroid species, there is still a considerable gap of knowledge as far as the detailed aspects of the repair phase at tissue and cellular level are concerned, particularly in post-traumatic regeneration. The present work is focused on the arm regeneration model in the Mediterranean red starfish Echinaster sepositus; to describe the early cellular mechanisms of arm regeneration following traumatic amputation, different microscopy techniques were employed. In E. sepositus, the repair phase was characterized by prompt wound healing by a syncytial network of phagocytes and re-epithelialisation followed by a localized subepidermal oedematous area formation. Scattered and apparently undifferentiated cells, intermixed with numerous phagocytes, were frequently found in the wound area during these first stages of regeneration and extensive dedifferentiation phenomena were seen at the level of the stump, particularly in the muscle bundles. A true localized blastema did not form. Our results confirm that regeneration in asteroids mainly relies on morphallactic processes, consisting in extensive rearrangement of the existing tissues which contribute to the new tissues through cell dedifferentiation, redifferentiation, and/or migration.

Histone deacetylase inhibitor reduces hypertrophic scarring in a rabbit ear model

BACKGROUND

Hypertrophic scars result from excessive collagen deposition at sites of healing dermal wounds and could be functionally and cosmetically problematic. The authors tested the ability of the histone deacetylase inhibitor trichostatin A to reduce hypertrophic scar formation in a rabbit ear model.

METHODS

The authors have developed a reliable rabbit model that results in hypertrophic scarring. Four 1-cm, full-thickness, circular wounds were made on each ear. After the wounds reepithelialized, 0.02% trichostatin A was injected intradermally into the wounds in the treatment group. Expression of collagen I and fibronectin was detected by reverse transcription polymerase chain reaction and Western blot analysis at postoperative day 23. Scar hypertrophy was quantified by measurement of the scar elevation index at postoperative day 45.

RESULTS

Compared with the control group, injection of trichostatin A led to much more normal-appearing scars in the rabbit ear. The scar elevation index at postoperative day 45 was significantly decreased after injection of trichostatin A compared with untreated scars. Furthermore, the authors confirmed the decreased expression of collagen I and fibronectin at postoperative day 23 (after the rabbits had been treated with trichostatin A for 1 week) in the treated scars compared with the control scars according to reverse transcription polymerase chain reaction and Western blot analysis.

CONCLUSIONS

The introduction of trichostatin A can result in the decreased formation of hypertrophic scars in a rabbit ear model, which is corroborated by evidence of decreased collagen I and fibronectin synthesis.

Effect of semisolid formulation of persea americana mill (avocado) oil on wound healing in rats

The aim of this study was to evaluate the wound-healing activity of a semisolid formulation of avocado oil, SSFAO 50%, or avocado oil in natura, on incisional and excisional cutaneous wound models in Wistar rats. An additional objective was to quantify the fatty acids present in avocado oil. On the 14th day, a significant increase was observed in percentage wound contraction and reepithelialization in the groups treated with 50% SSFAO or avocado oil compared to the petroleum jelly control. Anti-inflammatory activity, increase in density of collagen, and tensile strength were observed inSSFAO 50% or avocado oil groups, when compared to control groups. The analysis of the components of avocado oil by gas chromatography detected the majority presence of oleic fatty acid (47.20%), followed by palmitic (23.66%), linoleic (13.46%) docosadienoic (8.88%), palmitoleic (3.58%), linolenic (1.60%), eicosenoic (1.29%), and myristic acids (0.33%). Our results show that avocado oil is a rich source of oleic acid and contains essential fatty acids. When used in natura or in pharmaceutical formulations for topical use, avocado oil can promote increased collagen synthesis and decreased numbers of inflammatory cells during the wound-healing process and may thus be considered a new option for treating skin wounds.

Identification of steroid sensitive responders versus non-responders in the treatment of keloid disease

Intralesional corticosteroid injection is a well-recognised treatment modality for keloid disease (KD). Approximately 50% of KD cases are considered non-responders (or steroid resistant) with no consensus or indicators in detecting steroid-sensitive cases. In view of the undesirable side effects, uncertainty in timing and regularity of steroid treatment, we planned to identify responders and non-responders to target treatment more effectively. A scar injection proforma was developed capturing a detailed history focusing on symptoms and signs (redness, appearance, contour, texture, distortion and severity) associated with KD. The cause, site, number of keloid scars and scar recurrence were recorded as the lesions were injected on a monthly basis. A detailed description of response to steroid injection was documented and photographs were taken. Demographic data were collected on 65 patients (11 to 74 years with mean age 34.7 years, 60% were females, 50% were Caucasian). 77% (n = 50) were classified as steroid responders and showed improvement in symptoms and signs within 3 months. There was a statistically significant correlation between patients with higher contour scores of KD prior to treatment (p = 0.013) and frequency of injections (p = 0.003). Thus, the odds of being a responder were greater for patients with more than one injection and with higher contour scores. This preliminary case series has provided early evidence in enabling identification of steroid responders versus non-responders within a 3-month period. Selection of KD non-responders to steroid treatment can avoid potentially painful injection, its subsequent side effects and unnecessary continuation of redundant therapy and follow-up.

Profile of wound healing process induced by allantoin

PURPOSE: To evaluate and characterize the wound healing process profile induced by allantoin incorporated in soft lotion oil/water emulsion using the planimetric and histological methods. METHODS: Female Wistar rats (n=60) were randomly assigned to 3 experimental groups: (C) control group-without treatment; (E) group treated with soft lotion O/W emulsion excipients; (EA) group treated with soft lotion O/W emulsion containing allantoin 5%. The emulsions either containing or not allantoin were topically administered for 14 days and the wound area was evaluated by planimetry and by qualitative and quantitative histological analysis of open wound model. RESULTS: The data which were obtained and analyzed innovate by demonstrating, qualitatively and quantitatively, by histological analysis, the profile of healing process induced by allantoin. The results suggest that the wound healing mechanism induced by allantoin occurs via the regulation of inflammatory response and stimulus to fibroblastic proliferation and extracellular matrix synthesis. CONCLUSION: This work show, for the first time, the histological wound healing profile induced by allantoin in rats and demonstrated that it is able to ameliorate and fasten the reestablishment of the normal skin.

Pathological axes of wound repair: gastrulation revisited

Post-traumatic inflammation is formed by molecular and cellular complex mechanisms whose final goal seems to be injured tissue regeneration.

In the skin -an exterior organ of the body- mechanical or thermal injury induces the expression of different inflammatory phenotypes that resemble similar phenotypes expressed during embryo development. Particularly, molecular and cellular mechanisms involved in gastrulation return. This is a developmental phase that delineates the three embryonic germ layers: ectoderm, endoderm and mesoderm. Consequently, in the post-natal wounded skin, primitive functions related with the embryonic mesoderm, i.e. amniotic and yolk sac-derived, are expressed. Neurogenesis and hematogenesis stand out among the primitive function mechanisms involved.

Interestingly, in these phases of the inflammatory response, whose molecular and cellular mechanisms are considered as traces of the early phases of the embryonic development, the mast cell, a cell that is supposedly inflammatory, plays a key role.

The correlation that can be established between the embryonic and the inflammatory events suggests that the results obtained from the research regarding both great fields of knowledge must be interchangeable to obtain the maximum advantage.

Control of the skin scarring response

There comes a time when the understanding of the cutaneous healing process becomes essential due to the need for a precocious tissue repair to reduce the physical, social, and psychological morbidity. Advances in the knowledge on the control of interaction among cells, matrix and growth factors will provide more information on the Regenerative Medicine, an emerging area of research in medical bioengineering. However, considering the dynamism and complexity of the cutaneous healing response, it is fundamental to understand the control mechanism exerted by the interaction and synergism of both systems, cutaneous nervous and central nervous, via hypothalamus hypophysis-adrenal axis, a relevant subject, but hardly ever explored. The present study reviews the neuro-immune-endocrine physiology of the skin responsible for its multiple functions and the extreme disturbances of the healing process, like the excess and deficiency of the extracellular matrix deposition.

Basic fibroblast growth factor accelerates and improves second-degree burn wound healing

Second-degree burns are sometimes a concern for shortening patient suffering time as well as the therapeutic choice. Thus, adult second-degree burn patients (average 57.8 +/- 13.9 years old), mainly with deep dermal burns, were included. Patients receiving topical basic fibroblast growth factor (bFGF) or no bFGF were compared for clinical scar extent, passive scar hardness and elasticity using a Cutometer, direct scar hardness using a durometer, and moisture analysis of the stratum corneum at 1 year after complete wound healing. There was significantly faster wound healing with bFGF, as early as 2.2 +/- 0.9 days from the burn injury, compared with non-bFGF use (12.0 +/- 2.2 vs. 15.0 +/- 2.7 days, p<0.01). Clinical evaluation of Vancouver scale scores showed significant differences between bFGF-treated and non-bFGF-treated scars (p<0.01). Both maximal scar extension and the ratio of scar retraction to maximal scar extension, elasticity, by Cutometer were significantly greater in bFGF-treated scars than non-bFGF-treated scars (0.23 +/- 0.10 vs. 0.14 +/- 0.06 mm, 0.59 +/- 0.20 vs. 0.49 +/- 0.15 mm: scar extension, scar elasticity, bFGF vs. non-bFGF, p<0.01). The durometer reading was significantly lower in bFGF-treated scars than in non-bFGF-treated scars (16.2 +/- 3.8 vs. 29.3 +/- 5.1, p<0.01). Transepidermal water loss, water content, and corneal thickness were significantly less in bFGF-treated than in non-bFGF-treated scars (p<0.01).

Surgical inflammation: a pathophysiological rainbow

Tetrapyrrole molecules are distributed in virtually all living organisms on Earth. In mammals, tetrapyrrole end products are closely linked to oxygen metabolism. Since increasingly complex trophic functional systems for using oxygen are considered in the post-traumatic inflammatory response, it can be suggested that tetrapyrrole molecules and, particularly their derived pigments, play a key role in modulating inflammation.

In this way, the diverse colorfulness that the inflammatory response triggers during its evolution would reflect the major pathophysiological importance of these pigments in each one of its phases. Therefore, the need of exploiting this color resource could be considered for both the diagnosis and treatment of the inflammation.

Expression of collagen genes in the cones of skin in the Duroc/Yorkshire porcine model of fibroproliferative scarring

During the past decades there has been minimal improvement in prevention and treatment of hypertrophic scarring. Reasons include the lack of a validated animal model, imprecise techniques to dissect scar into the histologic components, and limited methodology for measurement of gene expression. These problems have been addressed with the Duroc/Yorkshire model of healing, laser capture microdissection, and the Affymetrix Porcine GeneChip. Here we compared collagen gene expression in fibroproliferative healing in the Duroc breed to nonfibroproliferative healing in the Yorkshires. We made shallow and deep dorsal wounds, biopsied at 1, 2, 3, 12, and 20 weeks. We sampled the dermal cones by laser capture microdissection, extracted and amplified the RNA, and hybridized Affymetrix Porcine GeneChips. We also obtained samples of human hypertrophic scar approximately 20 weeks postinjury. Data were normalized and statistical analysis performed with mixed linear regression using the Bioconductor R/maanova package. Genes for further analysis were also restricted with four biologic criteria, including that the 20-week deep Duroc expression match the human samples. Eleven collagen genes and seven collagen types were differentially over expressed in deep Duroc wounds including 1a1, 1a2, 3a1, 4a1, 4a2, 5a1, 5a2, 5a3, 6a3 (transcript variant 5), 14a1 and 15a1. COL7a1 gene was differentially under expressed in deep Duroc wounds. The results suggest that collagens I, III, IV, V, VI, VII, XIV, and XV [corrected] are involved in the process of fibroproliferative scarring. With these clues, we will attempt to construct the regulatory pathway(s) of fibroproliferative healing.

The Use of Corticosteroids to Treat Keloids: A Review

Mechanisms for keloid formation include drastic changes in growth factor actions, collagen turnover, mechanical forces applied over the skin, and genetic and immunologic contributions. The use of corticosteroids to manage keloids increases basic fibroblast growth factor production while decreasing transforming growth factor-β1 production by human dermal fibroblasts, endogenous vascular endothelial growth factor, and insulin-like growth factor-1. The use of corticosteroid injections is, to date, the core treatment available for the management of excessive tissue production in scars. Currently, the most effective and safe regimen for keloid management appears to be the use of corticotherapy—injection of intradermal steroids after a surgical excision.

Review of the female Duroc/Yorkshire pig model of human fibroproliferative scarring

Hypertrophic scarring after burns is an unsolved problem and remains as devastating today as it was in the 40s and it may be that the main reason for this is the lack of an accepted, useful animal model. The female, red Duroc pig was described as a model of hypertrophic scarring nearly 30 years ago but then vanished from the literature. This seemed strange since the authors reported that 12 of 12 pigs developed thick scar. In the mid 90s we explored the model and found that, indeed, the red Duroc pig does make thick scar. Other authors have established that the Yorkshire pig does not heal in this fashion so there is the possibility of a same species control. We have continued to explore the Duroc/Yorkshire model and herein describe our experiences. Is it a perfect model of hypertrophic scarring? No. Is it a useful model of hypertrophic scarring? Time will tell. We have now obtained gene expression data from the Duroc/Yorkshire model and analysis is underway.

Combined surgical excision and radiation therapy for keloid treatment

Various methods have been attempted for the treatment and management of keloids; however, there is little satisfactory clinical evidence in long-term follow ups. Also, there is a preference for occurrence and recurrence in anatomic location. Usually anatomic locations with higher regional tension and more sebaceous glands are inclined toward pathogenesis. Thirty-eight keloids treated with combined surgical excision and postoperative irradiation, using electron beams with only a 10-mm opening by lead shielding, were investigated at a mean follow up of 4.4 +/- 2.5 years (range, 1-9 years) at a single institute. Ten locations such as the ear (n = 6), neck (n = 3), and upper lip (n = 1) were among the craniofacial locations. The hardness of the keloids and posttreatment scars was clinically and objectively tested with the Vancouver scar scale and a durometer, which is often used for the industrial measurement of thread balls and rubber. At a mean of 4.4 +/- 2.5 years of follow up, the clinical characteristics of the scars were significantly better posttreatment as 2.6 +/- 0.5 versus 1.0 +/- 0.6, 3.7 +/- 0.7 versus 1.7 +/- 0.7, 2.9 +/- 0.4 versus 1.3 +/- 0.5, and 2.7 +/- 0.5 versus 1.3 +/- 0.5 (keloid scars versus posttreatment scars: pigmentation, pliability, height and vascularity, respectively, P < 0.01). The durometer readings were significantly lower posttreatment, 15.2 +/- 3.9 versus 7.7 +/- 2.9 (keloid scars versus posttreatment scars, P < 0.01). The recurrence rate was 21.2% overall with none in craniofacial locations. Therefore, the combined treatment of surgical excision and postoperative electron beam irradiation is effective for scar quality and reducing the recurrence rate in long-term follow up.

Histology of the thick scar on the female, red Duroc pig: final similarities to human hypertrophic scar

The etiology and treatment of hypertrophic scar remain puzzles even after decades of research. A significant reason is the lack of an accepted animal model of the process. The female, red Duroc pig model was described long ago. Since the skin of the pig is similar to that of humans, we are attempting to validate this model and found it to be encouraging. In this project we quantified myofibroblasts, mast cells and collagen nodules in the thick scar of the Duroc pig and compared these to the values for human hypertrophic scar. We found the results to be quite similar and so further validated the model. In addition, we observed that soon after wounding an inflammatory cell layer forms. The thickness of the inflammatory layer approaches the thickness of the skin removed as if the remaining dermis "knows" how much dermis is gone. In deep wounds this inflammatory layer thickens and this thickness is predictive of the thickness of the ultimate scar.

The quality of pediatric burn scars is improved by early administration of basic fibroblast growth factor

Pediatric burn wounds can be problematic because an accurate evaluation is difficult as the result of anatomically immature vasculature or immobilization failure, especially in patients with second-degree burns, and because the burn surface areas and the burn depth tend to worsen over the course of time. Delayed wound healing results in unsightly scarring, such as hypertrophic scars, which are problematic both esthetically and functionally. Among cytokines and growth factors, basic fibroblast growth factor (bFGF) is clinically proven, having demonstrated accelerated acute and chronic wound healing. Accelerated wound healing may lead to improved scarring. To elucidate the effects of bFGF on second-degree pediatric burn wounds, a comparative study was performed. A total of 20 pediatric patients ranging from 8 month to 3 years (average 1 year, 3 months +/- 6 months) who suffered from the burns by various causes were divided into two groups, conventional (n = 10) and treatment with bFGF (n = 10). A moisture meter, used to objectively measure the stratum corneum and epithelial-mesenchymal functions, was used to assess scars at least 1 year after wound healing. Clinical evaluation of pigmentation, pliability, height, and vascularity demonstrated significant differences between conventional and bFGF-treated scars (1.7 +/- 0.55 vs 0.7 +/- 0.58, 2.4 +/- 0.82 vs 1.1 +/- 0.69, 1.8 +/- 0.66 vs 0.5 +/- 0.57, 1.9 +/- 0.63 vs 0.8 +/- 0.68; conventional vs bFGF-treated, pigmentation, pliability, height, and vascularity, respectively, P < .01). The effective contact coefficient was significantly greater in conventional wounds than bFGF-treated wounds (14.6 +/- 1.68 % vs 8.7 +/- 2.82 %; conventional vs bFGF, P < .01) and bFGF-treated wounds demonstrated significantly less transepidermal water loss values than conventional treatment (8.3 +/- 1.90 g/m/h vs 5.7 +/- 1.85 g/m/hr; conventional vs bFGF, P < .01). Pediatric burn patients treated with bFGF showed less damaging function of the stratum corneum after healing both in clinical assessment and moisture meter analysis.

Upregulation of transforming growth factor-beta1 and vascular endothelial growth factor in cultured keloid fibroblasts: relevance to angiogenic activity

Keloids are tumor-like lesions that result from excessive scar formation during healing of wounds. Histologically, keloids show an increased blood vessel density compared with normal dermis or normal scars. However, the angiogenic activity of keloid fibroblasts remains unknown. In this study, we investigated angiogenic activity of keloid fibroblasts. Transforming growth factor-beta1 (TGF-beta1) and vascular endothelial growth factor (VEGF) were investigated as elements of the angiogenic factors. Expressions of TGF-beta1 and VEGF in conditioned medium were measured with enzyme-linked immunosorbent assay (EIA) and Northern blot analysis. Participation of TGF-beta1 in the production of VEGF was also investigated with addition of TGF-beta1 and a neutralizing anti-TGF-beta1 antibody. A modified Boyden chamber assay was performed to assess the chemotactic activity of vascular endothelial cells. Angiogenic activity in vivo was evaluated by neovascularization of nodules formed by implantation of fibroblasts into severe combined immunodeficiency (SCID) mice. EIA showed that the concentrations of TGF-beta1 and VEGF in conditioned medium were increased 2.5- and 6-fold, respectively, after the culture of keloid fibroblasts compared with normal fibroblasts. Northern blot analysis revealed that the expression of TGF-beta1 and VEGF mRNA was upregulated 3.6- and 6-fold, respectively, in keloid fibroblasts compared with normal fibroblasts. Addition of TGF-beta1 to keloid fibroblast cultures increased VEGF production by 3.5-fold, while there was a 6-fold in culture of normal fibroblasts. A neutralizing anti-TGF-beta1 antibody reduced VEGF secretion to control levels, suggesting that TGF-beta1 mediated the upregulation of VEGF expression. A modified Boyden chamber assay demonstrated that the chemotactic activity of vascular endothelial cells was more strongly (sevenfold) induced by keloid fibroblast-conditioned medium than by normal fibroblast-conditioned medium. Anti-VEGF antibody inhibited chemotaxis to basal levels. When SCID mice underwent implantation of fibroblasts into the back, the nodules formed by keloid fibroblasts were three times larger than those formed by normal fibroblasts. Although abundant neovascularization was observed in keloid fibroblast nodules, neovascularization was scarce in normal fibroblast nodules. Both in vitro and in vivo studies confirmed the significantly higher angiogenic activity of keloid fibroblasts compared with normal fibroblasts, and TGF-beta1 and VEGF were clearly shown to be involved. These results suggest that angiogenesis in keloids is promoted by endogenous TGF-beta1 and VEGF.

Novel Opportunities in the Treatment and Prevention of Scarring

Numerous treatments have been described for the treatment and prevention of scars, but the optimal management strategy is yet to be defined. In this article we present and evaluate new opportunities for the treatment and prevention of hypertrophic scars, keloids, and atrophic scars. Clinical, animal, and in vitro studies reporting novel techniques for the treatment and prevention of scarring were identified primarily from the MEDLINE/PubMed database. We found that a variety of new treatments exist with potential effectiveness for the treatment of hypertrophic scars and keloids, including interferon, imiquimod 5% cream, tacrolimus, botulinum toxin, 5-fluorouracil, bleomycin, and verapamil. For atrophic scars, different types of lasers represent modern treatment modalities with satisfactory results. Several agents have been reported to be effective in reducing scarring in vitro and in animal studies, representing potential opportunities for scarring management. We conclude that several novel modalities may be potential therapies for scarring.