Effect of mitomycin C on keloid fibroblasts: an in vitro study

Case report: Combination technique of balloon dilation, membrane excision, and topical mitomycin C for the treatment of nasopharyngeal stenosis in a cat

A two-year-old neutered male Turkish Angora cat presented with respiratory signs, including chronic snoring sounds and dyspnea with open-mouth breathing. Nasopharyngeal stenosis (NPS) was diagnosed based on endoscopy and computed tomography (CT). An attempt was made to break down the membrane, causing stenosis in the nasopharynx through balloon dilation using a valvuloplasty balloon dilation catheter (12 mm × 3 cm) and retroflexed endoscope. The balloon size was selected according to the identified diameter of the stenotic site on nasopharyngeal CT images. The balloon was inflated with radiographic contrast medium and maintained for 2 min; the similar procedure was repeated four additional times. The stenotic membrane was excised after balloon dilation. Topical Mitomycin C (MMC) was then administered to the stenotic region. After 2 weeks, an additional MMC application was repeated to prevent recurrence. The cat remained free of clinical signs without recurrence for 12 months after the most recent procedure. In this study, effective treatment results were obtained using a combination of balloon dilation, membrane excision, and topical MMC for membranous nasopharyngeal stenosis in a cat.

Hypertrophic Scars and Keloids: Advances in Treatment and Review of Established Therapies

Hypertrophic scars and keloids can have significant detrimental effects on patients both psychosocially and functionally. A careful identification of patient risk factors and a comprehensive management plan are necessary to optimize outcomes. Patients with a history of dystrophic scarring should avoid unnecessary procedures and enhance the wound-healing process using various preventive strategies. As there is no single, fully efficacious treatment modality, prevention remains the best approach in reducing aberrant scar formation. When prevention therapies fail, keloids have been shown to be respond to a variety of therapies including topical and injectable corticosteroids, 5-fluorouracil, radiotherapy, lasers, and surgical excision, all with varying efficacies. As such, management should be tailored to the individual patient's risk factors with the use of combination therapies to reduce recurrence rates. Still, keloid and hypertrophic scar therapies are widely diverse with novel treatment modalities providing alternatives for recurring lesions. Laser-assisted drug delivery, skin priming, and novel topical therapies may provide alternative options for the management of hypertrophic scars and keloids.

Role of Iron Oxide (Fe2O3) Nanocomposites in Advanced Biomedical Applications: A State-of-the-Art Review

Nanomaterials have demonstrated a wide range of applications and recently, novel biomedical studies are devoted to improving the functionality and effectivity of traditional and unmodified systems, either drug carriers and common scaffolds for tissue engineering or advanced hydrogels for wound healing purposes. In this regard, metal oxide nanoparticles show great potential as versatile tools in biomedical science. In particular, iron oxide nanoparticles with different shape and sizes hold outstanding physiochemical characteristics, such as high specific area and porous structure that make them idoneous nanomaterials to be used in diverse aspects of medicine and biological systems. Moreover, due to the high thermal stability and mechanical strength of Fe₂O₃, they have been combined with several polymers and employed for various nano-treatments for specific human diseases. This review is focused on summarizing the applications of Fe₂O₃-based nanocomposites in the biomedical field, including nanocarriers for drug delivery, tissue engineering, and wound healing. Additionally, their structure, magnetic properties, biocompatibility, and toxicity will be discussed.

Activation of the NFκB signaling pathway in IL6+CSF3+ vascular endothelial cells promotes the formation of keloids

Background: Keloid is a disease caused by abnormal proliferation of skin fibres, the causative mechanism of which remains unclear.

Method: In this study, endothelial cells of keloids were studied using scRNAseq combined with bulk-RNAseq data from keloids. The master regulators driving keloid development were identified by transcription factor enrichment analysis. The pattern of changes in vascular endothelial cells during keloid development was explored by inferring endothelial cell differentiation trajectories. Deconvolution of bulkRNAseq by CIBERSORTX verified the pattern of keloidogenesis. Immunohistochemistry for verification of the lesion process in keloid endothelial cells.

Results: The endothelial cells of keloids consist of four main cell populations (MMP1+ Endo0, FOS + JUN + Endo1, IL6+CSF3+Endo2, CXCL12 + Endo3). Endo3 is an endothelial progenitor cell, Endo1 is an endothelial cell in the resting state, Endo2 is an endothelial cell in the activated state and Endo0 is an endothelial cell in the terminally differentiated state. Activation of the NFΚB signaling pathway is a typical feature of Endo2 and represents the early skin state of keloids.

Conclusion: We have identified patterns of vascular endothelial cell lesions during keloidogenesis and development, and have found that activation of the NFΚB signaling pathway is an essential feature of keloid formation. These findings are expected to contribute to the understanding of the pathogenesis of keloids and to the development of new targeted therapeutic agents for the lesional characteristics of vascular endothelial cells.

Transurethral Incisions for Bladder Neck Contracture: Comparable Results without Intralesional Injections

To present our 12-year experience using an endoscopic approach to manage bladder neck contracture (BNC) without adjunctive intralesional agents and compare it to published series not incorporating them, we retrospectively reviewed 123 patients treated for BNC from 2008 to 2020. All underwent 24 Fr balloon dilation followed by transurethral incision of BNC (TUIBNC) with deep incisions at 3 and 9 o'clock using a Collins knife without the use of intralesional injections. Success was defined as a patent bladder neck and 16 Fr cystoscope passage into the bladder two months later. Most with recurrent BNC underwent repeat TUIBNC. Success rates, demographics, and BNC characteristics were analyzed. The etiology of BNC in our cohort was most commonly radical prostatectomy with or without radiation (36/123, 29.3%, 40/123, 32.5%). Some had BNC treatment prior to referral (30/123, 24.4%). At 12-month follow-up, bladder neck patency was observed in 101/123 (82.1%) after one TUIBNC. An additional 15 patients (116/123, 94.3%) had success after two TUIBNCs. On univariate and multivariate analyses, ≥2 endoscopic treatments was the only factor associated with failure. TUIBNC via balloon dilation and deep bilateral incisions without the use of adjunctive intralesional injections has a high patency rate. History of two or more prior endoscopic procedures is associated with failure.

Nuclear medicine in the management of superficial skin abnormalities and institutional experience

Keloid, hypertrophic scars and basal cell carcinoma (BCC) falls under the category of non-melanoma skin cancer. Intralesional steroids, external beam radiation therapy, 5-Fluorouracil, cryotherapy, laser, etc are the available treatment options. However, recurrence has been reported with each type of treatment mode. In the present article, various treatment modes have been discussed and institutional experience of Rhenium-188 skin patches for the treatment of keloids and BCC has been discussed.

Wound Closure Following Intervention for Closed Orthopedic Trauma

The method of skin closure and post-operative wound management has always been important in orthopedic surgery and plays an even larger role now that surgical site infection (SSI) is a national healthcare metric for both surgeons and hospitals. Wound related issues remain some of the most feared complications following orthopedic trauma procedures and are associated with significant morbidity. In order to minimize the risk of surgical site complications, surgeons must be familiar with the physiology of wound healing as well as the patient and surgical factors affecting healing potential. The goal of all skin closure techniques is to promote rapid healing with acceptable cosmesis, all while minimizing risk of infection and dehiscence. Knowledge of the types of closure material, techniques of wound closure, surgical dressings, negative pressure wound therapy, and other local modalities is important to optimize wound healing. There is no consensus in the literature as to which closure method is superior but the available data can be used to make informed choices. Although often left to less experienced members of the surgical team, the process of wound closure and dressing the wound should not be an afterthought, and instead must be part of the surgical plan. Wounds that are in direct communication with bony fractures are particularly at risk due to local tissue trauma, resultant swelling, hematoma formation, and injured vasculature.

Treatment of Keloids: A Meta-analysis of Intralesional Triamcinolone, Verapamil, and Their Combination

Keloids are skin lesions of abnormal and excessive scar proliferation that have no agreed upon gold standard of therapy. Extensive research in this area has shown that both intralesional triamcinolone and verapamil are effective in their treatment.

Topical versus interlesional mitomycin C in auricular keloids

BACKGROUND

The Keloid is an elevated fibrous scar that may extend beyond the borders of the original wound.

OBJECT

To compare between topical and intralesional mitomycin C in the treatment of auricular keloids.

PATIENTS AND METHODS

Prospective randomized study in which 40 patients with auricular keloids were included. The patients were divided into 2 groups, Group I included 32 patients who underwent topical mitomycin C application after the surgical removal of the auricular keloids, while Group II included 8 cases who underwent intra-lesional injection of mitomycin C after surgical removal of the auricular keloids.

RESULTS

The two groups showed no significant difference regarding patient or lesion criteria (p>.05). VSS decreased significantly from 10.63 and 11.0 down to 1.38 and 3.0 after treatment in the topical and intra-lesional groups respectively (p<.001). However, greater improvement and satisfaction was detected in the topical group.

CONCLUSION

Both topical and intra-lesional mitomycin C injection are effective methods in managing auricular keloids. However, better VSS scores and patient satisfaction are reported with topical administration.

Incorporating intra-lesional injection of mitomycin C in the management algorithm for bladder neck contractures and vesicourethral anastomotic strictures

Objective:

This study aims to describe the experience of a single-surgeon series with the use of intra-lesional mitomycin C (MMC) in the treatment of bladder neck contracture (BNC) and vesicourethral anastomotic stenosis (VUAS).

Patients and methods:

From July 2014 to January 2019, patients who underwent bladder neck incision (BNI) and intra-lesional MMC injection performed by a single surgeon were included in this retrospective study. Clinico-pathological data were extracted from medical records. The primary outcome was recurrence rate following BNI and MMC injection.

Results:

Ten patients were included in the study. The median age was 68 years. The cause of BNC or VUAS was secondary to radical prostatectomy in eight patients and to endoscopic prostatectomy in two patients. The median follow-up was 16.4 months. The success rate was 70% after first treatment with BNI and MMC injection, and 80% after repeated treatment. There were no serious adverse events or complications related to the MMC injection.

Conclusion:

BNI and intra-lesional MMC injection is a minimally invasive treatment for refractory bladder neck contractures with a good success rate and minimal risk of side effects when a low dose of MMC is used. Further prospective multicentre study is warranted.

Level of evidence:

Level 4.

Intra-articular injection of mitomycin C prevents progression of immobilization-induced arthrogenic contracture in the remobilized rat knee

This study tested whether cell cycle inhibitor mitomycin C (MMC) prevents arthrogenic contracture progression during remobilization by inhibiting fibroblast proliferation and fibrosis in the joint capsule. Rat knees were immobilized in a flexed position to generate flexion contracture. After three weeks, the fixation device was removed and rat knees were allowed to freely move for one week. Immediately after and three days after fixator removal, rats received intra-articular injections of MMC or saline. The passive extension range of motion (ROM) was measured before and after myotomy of the knee flexors to distinguish myogenic and arthrogenic contractures. In addition, both cellularity and fibrosis in the posterior joint capsule were assessed histologically. Joint immobilization significantly decreased ROMs both before and after myotomy compared with untreated controls. In saline-injected knees, remobilization increased ROM before myotomy, but further decreased that after myotomy compared with that of knees immediately after three weeks of immobilization. Histological analysis revealed that hypercellularity, mainly due to fibroblast proliferation, and fibrosis characterized by increases in collagen density and joint capsule thickness occurred after remobilization in saline-injected knees. Conversely, MMC injections were able to prevent the remobilization-enhanced reduction of ROM after myotomy by inhibiting both hypercellularity and joint capsule fibrosis. Our results suggest that joint capsule fibrosis accompanied by fibroblast proliferation is a potential cause of arthrogenic contracture progression during remobilization, and that inhibiting fibroblast proliferation may constitute an effective remedy.

The effect of 5α-oleandrin on keloid fibroblast activities

Background

Keloids develop due to hyperactivity of keloid fibroblast (KF) in proliferation, migration, and collagen deposition along with low rates of collagen degradation. These are a result of the Wnt/β catenin signaling pathways under stimulation of TGF-β. 5α-oleandrin can suppress Wnt-targeted genes of osteosarcoma cells. We aimed to evaluate the anti-fibrotic effects of 5α-oleandrin on KF activities.

Methods

We collected the core of keloid materials from six patients who underwent keloid debulking surgery. Passage 4 of KF cells were then treated with mitomycin-C, 5α-oleandrin, and dilution medium as the negative control. To determine the effective dose of 5α-oleandrin, we diluted 5α-oleandrin into various concentrations. The incubation periods were 24 h, 48 h, and 72 h. The anti-proliferation and anti-fibrotic properties were measured using standard assay.

Results

Both the mitomycin-C and 5α-oleandrin treated groups indicated decrease in proliferation index (86.16 ± 4.20% and 73.76 ± 4.94%, respectively), collagen deposition index (90.26 ± 1.72% and 71.35 ± 4.26%, respectively), and migration capacity (33.51 ± 1.50% and 28.57 ± 1.58%, respectively). These were significant changes (p ≤ 0.05) compared to the non-treated group. Antifibrotic activities of 5α-oleandrin in cellular proliferation and collagen deposition were better than mitomycin-C.

Conclusions

The 5α-oleandrin has good antifibrotic effect in keloid fibroblast activities.

Keloids: Current and emerging therapies

Keloids are pathological scars that grow over time and extend beyond the initial site of injury after impaired wound healing. These scars frequently recur and rarely regress. They are aesthetically disfiguring, can cause pain, itching, discomfort as well as psychological stress, often affecting quality of life. Many treatment modalities, including surgical and non-surgical, have been explored and have been reported to be beneficial; however, none have been absolutely satisfactory or optimal for the treatment of all keloid subtypes to date. This poses a major challenge to clinicians. Often, a combinational therapeutic approach appears to offer the best results with higher patient satisfaction compared to monotherapy. The aetiopathogenesis of keloids is not fully elucidated; however, with recent advances in molecular biology and genetics, insight is being gained on the complex process of scar formation and hence new therapeutic and management options for keloids. In this paper, we explore the literature and summarise the general concepts surrounding keloid development and review both current (corticosteroids, surgical excision, silicone-based products, pressure therapy, radiotherapy, cryotherapy, laser therapy, imiquimod and 5-fluorouracil) and emerging (stem cell therapy, mitomycin C, verapamil, interferons, bleomycin, botulinum toxin type A and angiotensin-converting enzyme inhibitors) treatments. Increased knowledge and understanding in this area may potentially lead to the discovery and development of novel therapeutic options that are more efficacious for all keloid types.

LAY SUMMARY

Keloids are problematic scars that are difficult to treat and manage. The aetiopathogenesis of keloids is not clear; however, recent advances in molecular biology and genetics are beginning to shed light on the underlying mechanisms implicated in keloid scar formation which will hopefully lead to the development of treatment options for all keloid types. This review summarises current and emerging therapies.

Scar management in burn injuries using drug delivery and molecular signaling: Current treatments and future directions

In recent decades, there have been tremendous improvements in burn care that have allowed patients to survive severe burn injuries that were once fatal. However, a major limitation of burn care currently is the development of hypertrophic scars in approximately 70% of patients. This significantly decreases the quality of life for patients due to the physical and psychosocial symptoms associated with scarring. Current approaches to manage scarring include surgical techniques and non-surgical methods such as laser therapy, steroid injections, and compression therapy. These treatments are limited in their effectiveness and regularly fail to manage symptoms. As a result, the development of novel treatments that aim to improve outcomes and quality of life is imperative. Drug delivery that targets the molecular cascades of wound healing to attenuate or prevent hypertrophic scarring is a promising approach that has therapeutic potential. In this review, we discuss current treatments for scar management after burn injury, and how drug delivery targeting molecular signaling can lead to new therapeutic strategies.

Autologous adipose-derived stem cell sheets enhance the strength of intestinal anastomosis

Objective

Adipose-derived stem cells (ASCs) are capable of multiple differentiation pathways, imparting immunomodulatory effects, and secreting factors that are important for wound healing. These characteristics can be exploited to decrease the incidence of anastomotic leakage.

Methods

In order to delay local wound healing at the anastomotic site, we induced ischemia in a portion of porcine small intestine by ligating vessels. Then, we injected mitomycin C into the serosa of the small intestine above the ligated vessels. Anastomotic sites were created by 2 cm incisions made in the opposite mesenteric area. ASCs were isolated from the porcine subcutaneous fat tissues and expanded under culture conditions. ASCs were trypsinized and seeded on temperature-responsive dishes and cultured to form confluent sheets. Three ASC sheets were transplanted onto the serous membrane after suturing. The extent of anastomotic wound healing was evaluated by bursting pressure, hydroxyproline content, and mRNA expression of collagen-1 alpha1 and collagen-3 alpha1.

Results

We found that transplantation of ASC sheets increased anastomotic site bursting pressure. Additionally, transplantation of ASC sheets increased the hydroxyproline content of the anastomoses. Furthermore, transplantation of ASC sheets increased mRNA expression of collagen-1 alpha1 and collagen-3 alpha1.

Conclusions

Our findings showed that transplantation of autologous ASC sheets enhanced collagen synthesis and anastomotic strength. Further studies are necessary to identify substances that, in combination with ASC sheets, might enhance collagen synthesis and healing in sites of anastomosis.

•

Transplantation of adipose-derived stem cell (ASC) sheets after intestinal anastomosis stimulated collagen synthesis and improved anastomotic strength.

•

Paracrine effects of the growth factors released by the ASC sheets might contribute to healing at the anastomotic site and stimulate the fibroblast and the collagen synthesis.

•

This new approach might be a feasible and promising strategy to prevent anastomotic leakage.

Novel Insights on Understanding of Keloid Scar: Article Review

Keloid scar, dermal benign fibro-proliferative growth that extends outside the original wound and invades adjacent dermal tissue due to extensive production of extracellular matrix, especially collagen, which caused by over expression of cytokines and growth factors. Although many attempts were made to understand the exact pathophysiology and the molecular abnormalities, the pathogenesis of keloid scar is yet to be determined. Even though there are several treatment options for keloid scars include combination of medical and surgical therapies like combination of surgical removal followed by cryotherapy or intralesional steroid therapy, the reoccurrence rate is still high despite the present treatment. In this review, PubMed, clinical key and Wright State Library web site have been used to investigate any update regarding Keloid disease. We used Keloid, scar formation, hypertrophic scar and collagen as key words. More than 40 articles have been reviewed. This paper reviews literature about keloid scar formation mechanism, the most recent therapeutic options including the ones under research.

Efficacy of 2 Representative Topical Agents to Prevent Keloid Recurrence After Surgical Excision

PURPOSE

Keloids are difficult to remove successfully and there is no universally accepted treatment. After surgical excision of the keloid, there are various management methods for prevention of keloid recurrence, such as intralesional injection, radiation, and topical agents. A few studies have compared topical agents with other treatments. The aim of this study was to investigate effective topical agents for the prevention of recurrent keloid after surgical excision.

MATERIALS AND METHODS

Eligible articles were sought using core databases, including Medline, Embase, and Cochrane databases, up to April 2016. The predictor variables were mitomycin C (MC) and imiquimod cream treatment after keloid excision. The outcome variable was keloid recurrence rate.

RESULTS

The search strategy identified 120 publications. After screening, 9 articles were selected for review. Articles were divided into 2 groups: MC and imiquimod cream. The recurrence rate after surgical excision in the MC group was estimated to be 16.5%, and that in the imiquimod cream group was estimated to be 24.7%.

CONCLUSION

If intralesional injection or radiation is not available, then MC or imiquimod 5% cream could be an effective alternative in preventing keloid recurrence.

Keloids and Hypertrophic Scars: A Spectrum of Clinical Challenges

Since their earliest description, keloids and hypertrophic scars have beleaguered patients and clinicians alike. These scars can be aesthetically disfiguring, functionally debilitating, emotionally distressing, and psychologically damaging, culminating in a significant burden for patients. Our current understanding of keloid pathophysiology has grown and continues to advance while molecular biology, genetics, and technology provide ever-deepening insight into the nature of wound healing and the pathologic perturbations thereof. Greater understanding will lead to the development and application of refined therapeutic modalities. This article provides an overview of our current understanding of keloids, highlighting clinical characteristics and diagnostic criteria while providing a comprehensive summary of the many therapeutic modalities available. The proposed mechanism, application, adverse events, and reported efficacy of each modality is evaluated, and current recommendations are summarized.

The Effects of Intradermal and Topical Mitomycin C on Wound Healing

OBJECTIVE: To determine the effect of intradermal and topical mitomycin C (MMC) on skin wound healing.

STUDY DESIGN/SETTING: A prospective, controlled study in a rat wound model performed in an academic medical center.

RESULTS: Intradermal and topical MMC application decreased wound integrity when compared with saline-treated animals at 1 week, 2 weeks, 1 month, and 6 months. Skin necrosis occurred in animals that received intradermal MMC. Hemotoxylin and eosin and immunohistochemical staining showed no consistent difference between treatment arms. Fibrosis and collagen deposition were reduced in MMC-treated wounds on trichrome staining.

CONCLUSIONS: MMC-treated wounds showed decreased wound strength compared with controls. Intradermal MMC can cause skin necrosis. Histologic findings did not always correspond with clinical data.

SIGNIFICANCE: The data suggest cautious use of MMC in clinical situations when wound breaking strength is critical.

Application of mitomycin-C for head and neck keloids

Keloids of the head and neck are a relatively common entity in darker-skinned races, occurring in 5%-15% of skin wounds. Keloids are fibrotic lesions that are a result of an abnormal wound-healing process that lacks control of the mechanisms that regulate tissue repair and regeneration. The proliferation of normal tissue-healing processes results in scarring that enlarges well beyond the original wound margins.

Many treatment modalities for keloids have been tried with variable amounts of success. Surgical excision, compressive therapy, silicon dressings, corticosteroid injections, radiation, cryotherapy, interferon therapy, and laser therapy have all been used alone or in combination. Despite this wide range of available treatments, recurrence rates typically remain in the 50%-70% range.

In this study, we present our results in a series of 10 patients who were treated with surgical excision of head and neck keloids and the application of topical mitomycin-C. Mitomycin-C is a chemotherapeutic agent that inhibits DNA synthesis and fibroblast proliferation. It has been used in ophthalmologic procedures and airway surgery to decrease scar formation. In these 10 patients, we combined surgical excision of keloids with the application of topical mitomycin-C. The patients were then followed postoperatively for recurrence (range, 7-14 months). We have found topical application of mitomycin-C to be an effective therapy for prevention of keloid recurrence in the head and neck, with a success rate of 90% as reported in this series.

New frontiers in urethral reconstruction: injectables and alternative grafts

Contemporary management of anterior urethral strictures requires both endoscopic as well as complex substitution urethroplasty, depending on the nature of the urethral stricture. Recent clinical and experimental studies have explored the possibility of augmenting traditional endoscopic urethral stricture management with anti-fibrotic injectable medications. Additionally, although buccal mucosa remains the gold standard graft for substitution urethroplasty, alternative grafts are necessary for reconstructing particularly complex urethral strictures in which there is insufficient buccal mucosa or in cases where it may be contraindicated. This review summarizes the data of the most promising injectable adjuncts to endoscopic stricture management and explores the alternative grafts available for reconstructing the most challenging urethral strictures. Further research is needed to define which injectable medications and alternative grafts may be best suited for urethral reconstruction in the future.

A comprehensive evidence-based review on the role of topicals and dressings in the management of skin scarring

Wound healing after dermal injury is an imperfect process, inevitably leading to scar formation as the skin re-establishes its integrity. The resulting scars have different characteristics to normal skin, ranging from fine-line asymptomatic scars to problematic scarring including hypertrophic and keloid scars. Scars appear as a different colour to the surrounding skin and can be flat, stretched, depressed or raised, manifesting a range of symptoms including inflammation, erythema, dryness and pruritus, which can result in significant psychosocial impact on patients and their quality of life. In this paper, a comprehensive literature review coupled with an analysis of levels of evidence (LOE) for each published treatment type was conducted. Topical treatments identified include imiquimod, mitomycin C and plant extracts such as onion extract, green tea, Aloe vera, vitamin E and D, applied to healing wounds, mature scar tissue or fibrotic scars following revision surgery, or in combination with other more established treatments such as steroid injections and silicone. In total, 39 articles were included, involving 1703 patients. There was limited clinical evidence to support their efficacy; the majority of articles (n = 23) were ranked as category 4 LOE, being of limited quality with individual flaws, including low patient numbers, poor randomisation, blinding, and short follow-up periods. As trials were performed in different settings, they were difficult to compare. In conclusion, there is an unmet clinical need for effective solutions to skin scarring, more robust long-term randomised trials and a consensus on a standardised treatment regime to address all aspects of scarring.

The Use of Chemotherapeutics for the Treatment of Keloid Scars

Keloid scars are pathological scars, which develop as a result of exaggerated dermal tissue proliferation following cutaneous injury and often cause physical, psychological and cosmetic problems. Various theories regarding keloidogenesis exist, however the precise pathophysiological events remain unclear. Many different treatment modalities have been implicated in their management, but currently there is no entirely satisfactory method for treating all keloid lesions. We review a number of different chemotherapeutic agents which have been proposed for the treatment of keloid and hypertrophic scars while giving insight into some of the novel chemotherapeutic drugs which are currently being investigated. Non-randomized trials evaluating the influence of different chemotherapeutic agents, such as 5-fluorouracil (5-FU); mitomycin C; bleomycin and steroid injection, either alone or in combination with other chemotherapeutic agents or alternative treatment modalities, for the treatment of keloids were identified using a predefined PubMed search strategy. Twenty seven papers were identified. Scar improvement ≥50% was found in the majority of cases treated with 5-FU, with similar results found for mitomycin C, bleomycin and steroid injection. Combined intralesional 5-FU and steroid injection produced statistically significant improvements when compared to monotherapy. Monotherapy recurrence rates ranged from 0-47% for 5-FU, 0-15% for bleomycin and 0-50% for steroid injection. However, combined therapy in the form of surgical excision and adjuvant 5-FU or steroid injections demonstrated lower recurrence rates; 19% and 6% respectively. Currently, most of the literature supports the use of combination therapy (usually surgery and adjuvant chemotherapy) as the mainstay treatment of keloids, however further investigation is necessary to determine success rates over longer time frames. Furthermore, there is the potential for novel therapies, but further investigation is required to elucidate their true efficacy.

Intralesional injection of mitomycin C at transurethral incision of bladder neck contracture may offer limited benefit: TURNS Study Group

PURPOSE

Injection of mitomycin C may increase the success of transurethral incision of the bladder neck for the treatment of bladder neck contracture. We evaluated the efficacy of mitomycin C injection across multiple institutions.

MATERIALS AND METHODS

Data on all patients who underwent transurethral incision of the bladder neck with mitomycin C from 2009 to 2014 were retrospectively reviewed from 6 centers in the TURNS. Patients with at least 3 months of cystoscopic followup were included in the analysis.

RESULTS

A total of 66 patients underwent transurethral incision of the bladder neck with mitomycin C and 55 meeting the study inclusion criteria were analyzed. Mean ± SD patient age was 64 ± 7.6 years. Dilation or prior transurethral incision of the bladder neck failed in 80% (44 of 55) of patients. Overall 58% (32 of 55) of patients achieved resolution of bladder neck contracture after 1 transurethral incision of the bladder neck with mitomycin C at a median followup of 9.2 months (IQR 11.7). There were 23 patients who had recurrence at a median of 3.7 months (IQR 4.2), 15 who underwent repeat transurethral incision of the bladder neck with mitomycin C and 9 of 15 (60%) who were free of another recurrence at a median of 8.6 months (IQR 8.8), for an overall success rate of 75% (41 of 55). Incision with electrocautery (Collins knife) was predictive of success compared with cold knife incision (63% vs 50%, p=0.03). Four patients experienced serious adverse events related to mitomycin C and 3 needed or are planning cystectomy.

CONCLUSIONS

The efficacy of intralesional injection of mitomycin C at transurethral incision of the bladder neck was lower than previously reported and was associated with a 7% rate of serious adverse events.

The preliminary study of effects of tolfenamic Acid on cell proliferation, cell apoptosis, and intracellular collagen deposition in keloid fibroblasts in vitro

Keloid scarring is a fibroproliferative disorder due to the accumulation of collagen type I. Tolfenamic acid (TA), a nonsteroidal anti-inflammatory drug, has been found to potentially affect the synthesis of collagen in rats. In this preliminary study, we aimed to test the effects of TA on cell proliferation, cell apoptosis, and the deposition of intracellular collagen in keloid fibroblasts. Normal fibroblasts (NFs) and keloid fibroblasts (KFs) were obtained from human dermis tissue. Within the dose range 10⁻³–10⁻⁶ M and exposure times 24 h, 48 h, and 72 h, we found that 0.55 × 10⁻³ M TA at 48 h exposure exhibited significantly decreased cell proliferation in both NFs and KFs. Under these experimental conditions, we demonstrated that (1) TA treatment induced a remarkable apoptotic rate in KFs compared to NFs; (2) TA treatment reduced collagen production in KFs versus NFs; (3) TA treatment decreased collagen type I expression in KFs comparing to that of NFs. In summary, our data suggest that TA decreases cell proliferation, induces cell apoptosis, and inhibits collagen accumulation in KFs.

Adjunctive maneuvers to treat urethral stricture: a review of the world literature

The development of urethral stricture (US) or bladder neck contracture is a relatively uncommon but well described condition observed primarily in men. Despite familiarity with US disease, management remains challenging for urologists. Risk factors for the development of USs or bladder neck contracture include primary treatment modality, tobacco smoking, coronary artery disease and poorly controlled diabetes mellitus. Numerous treatment options exist for this condition that vary in procedural complexity, including intermittent self catheterization (CIC), serial urethral dilation, endoscopic techniques and open reconstructive repairs. Repetitive procedures for this condition may carry increased failure rates and morbidities. For the treatment of refractory or recalcitrant bladder neck contracture, newer intralesional anti-proliferative, anti-scar agents have been used in combination with transurethral bladder neck incisions to augment outcome and long-term effect. The primary focus of this systematic review of the published literature is to streamline and summarize various and newer therapeutic modalities available to manage patients with US or bladder neck contracture.

Preliminary results of antiscarring therapy in the prevention of postendoscopic esophageal mucosectomy strictures

BACKGROUND

Esophageal endoscopic submucosal dissection (ESD) is an effective minimally invasive therapy for early esophageal cancer and high-grade Barrett dysplasia. However, esophageal stricture formation after circumferential or large ESD has limited its wide adoption. Mitomycin C (MMC), halofuginone (Hal), and transforming growth factor β3 (TGF-β3) exhibits antiscarring effects that may prevent post-ESD stricture formation.

METHODS

Using endoscopic mucosectomy (EEM) technique, an 8- to 10-cm-long circumferential esophageal mucosal segment was excised in a porcine model. The site was either untreated (control, n = 6) or received 40 evenly distributed injections of antiscarring agent immediately and at weeks 1 and 2. High and low doses were used: MMC 5 mg (n = 2), 0.5 mg (n = 2); Hal 5 mg (n = 2), 1.5 mg (n = 2), 0.5 mg (n = 2); TGF-β3 2 μg (n = 2), 0.5 μg (n = 2). The degree of stricture formation was determined by the percentage reduction of the esophageal lumen on weekly fluoroscopic examination. Animals were euthanized when strictures exceeded 80 % or the animals were unable to maintain weight.

RESULTS

The control group had a luminal diameter reduction of 78.2 ± 10.9 % by 2 weeks and were euthanized by week 3. Compared at 2 weeks, the Hal group showed a decrease in mean stricture formation (68.4 % low dose, 57.7 % high dose), while both TGF-β3 dosage groups showed no significant change (65.3 % low dose, 76.2 % high dose). MMC was most effective in stricture prevention (53.6 % low dose, 35 % high dose). Of concern, the esophageal wall treated with high-dose MMC appeared to be necrotic and eventually led to perforation. In contrast, low dose MMC, TGF-β3 and Hal treated areas appeared re-epithelialized and healthy.

CONCLUSIONS

Preliminary data on MMC and Hal demonstrated promise in reducing esophageal stricture formation after EEM. More animal data are needed to perform adequate statistical analysis in order to determine overall efficacy of antiscarring therapy.

Pharmacological treatment for keloids

INTRODUCTION

Keloids are fibroproliferative disorders that are characterized by histological accumulation of collagens and fibroblasts, refractory clinical symptoms such as itching, topical invasiveness, and frequent postsurgical recurrence. At present, to treat or prevent keloids, new drugs are currently being designed and the pharmaceutical indications of known drugs are being expanded.

AREAS COVERED

The current pharmacological interventions for keloids are mainly described on the basis of the various hypotheses on keloid etiology and the keloid ingredients that are targeted. These interventions include angiotension-converting enzyme inhibitors and calcium-channel blockers (based on hypertension hypothesis), selective estrogen receptor modulator (based on endocrinological hypothesis), vitamins and essential fatty acids (based on immunonutritional hypothesis), and transglutaminase inhibitor (based on metabolic hypothesis). Drugs that directly target the reduction or destruction of the major extracellular matrix or cellular constituents of keloids are also included. Besides, drugs that indirectly modulate the biochemical microenvironment are described. These include growth factors, immunomodulators, and anti-inflammation and anti-allergy drugs.

EXPERT OPINION

Due to the unclear etiology of keloids and the lack of animal models, efficient, reliable, and specific pharmaceutical interventions for keloids continue to be lacking. The reliability of current data and clinical observations must be strengthened by large-scale, randomized, controlled clinical trials.

Role of Hyaluronic Acid Treatment in the Prevention of Keloid Scarring

BACKGROUND

Keloids are benign dermal scars characterized by enhanced growth factor signaling, hyperproliferation activity and reduced extracellular matrix (ECM) deposition of hyaluronic acid. Our hypothesis is that high molecular weight HA can be used to replenish HA deposition in keloids thereby normalizing the keloid fibroblast phenotype.

METHODS

One normal (NF1) fibroblast culture and five keloid (KF1, KF2, KF3, KF4, KF5) fibroblast cultures were analyzed for changes in hyperproliferation, growth factor production and extracellular matrix deposition following 72 hour treatment with or without 10 μg/ml HA.

RESULTS

Proliferation activity decreased significantly in KF3 following HA treatment. Pro-collagen I expression in KF2 was decreased following HA treatment in association with changes in fiber arrangement to more parallel collagen bundles. In addition, HA demonstrated a downregulation on TGF-b1 growth factor expression in KF3 and KF4 and a decrease in active TGF-b1 release in KF2 and KF5 using ELISA.

CONCLUSION

Our data demonstrates that HA has the potential to normalize keloid fibroblast characteristic features such as hyperproliferation, growth factor production and ECM deposition depending on the specific genotype of the keloid fibroblast cell line. This study suggests that high molecular weight HA can be used to replenish HA deposition in keloid fibroblasts thereby decreasing fibrosis and ultimately decreasing keloid manifestation.

Effect of mitomycin on normal dermal fibroblast and HaCat cell: an in vitro study

OBJECTIVE

To evaluate the effects of mitomycin on the growth of human dermal fibroblast and immortalized human keratinocyte line (HaCat cell), particularly the effect of mitomycin on intracellular messenger RNA (mRNA) synthesis of collagen and growth factors of fibroblast.

METHODS

The normal dermal fibroblast and HaCat cell were cultured in vitro. Cell cultures were exposed to 0.4 and 0.04 mg/ml of mitomycin solution, and serum-free culture medium was used as control. The cellular morphology change, growth characteristics, cell proliferation, and apoptosis were observed at different intervals. For the fibroblasts, the mRNA expression changes of transforming growth factor (TGF)-β1, basic fibroblast growth factor (bFGF), procollagen I, and III were detected by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

The cultured normal human skin fibroblast and HaCat cell grew exponentially. A 5-min exposure to mitomycin at either 0.4 or 0.04 mg/ml caused marked dose-dependent cell proliferation inhibition on both fibroblasts and HaCat cells. Cell morphology changed, cell density decreased, and the growth curves were without an exponential phase. The fibroblast proliferated on the 5th day after the 5-min exposure of mitomycin at 0.04 mg/ml. Meanwhile, 5-min application of mitomycin at either 0.04 or 0.4 mg/ml induced fibroblast apoptosis but not necrosis. The apoptosis rate of the fibroblast increased with a higher concentration of mytomycin (p<0.05). A 5-min exposure to mitomycin at 0.4 mg/ml resulted in a marked decrease in the mRNA production of TGF-β1, procollagen I and III, and a marked increase in the mRNA production of bFGF.

CONCLUSIONS

Mitomycin can inhibit fibroblast proliferation, induce fibroblast apoptosis, and regulate intracellular protein expression on mRNA levels. In addition, mitomycin can inhibit HaCat cell proliferation, so epithelial cell needs more protecting to avoid mitomycin's side effect when it is applied clinically.

Inhibition of collagen fibril formation

Background

The overall aim of presented study is to test the inhibition of the formation of collagen fibrils as the novel approach to reduce accumulation of pathological fibrotic deposits. The main hypothesis is that by interfering with the initial steps of the extracellular process of collagen fibril formation, it is possible to reduce the formation of fibrotic tissue.

Methods

The experimental model includes antibody-based inhibitors that specifically bind to the sites that participate in the collagen/collagen interaction.

Results

Employed antibody-based inhibitors effectively limit the amount of collagen fibrils formed in vitro and in engineered tissue models of localized fibrosis.

Conclusions

(i) Inhibition of collagen formation is an attractive target to reduce excessive formation of fibrotic tissue.

(ii) Antibody-based inhibitors of collagen fibril formation are promising therapeutic agents with a potential to limit localized fibrosis in a number of tissues.

Radial urethrotomy and intralesional mitomycin C for the management of recurrent bladder neck contractures

PURPOSE

We evaluated urethrotomy combined with intralesional injection of the antiproliferative agent mitomycin C for the treatment of severe, recurrent bladder neck contractures after traditional endoscopic management failed. We report our experience with radial urethrotomy and intralesional mitomycin C in patients with recurrent bladder neck contractures.

MATERIALS AND METHODS

A retrospective review was performed of patients evaluated for severe, recurrent bladder neck contractures between January 2007 and April 2010. All patients had at least 1 prior failed incision of a bladder neck contracture. Tri or quadrant cold knife incisions of the bladder neck were performed followed by injection of 0.3 to 0.4 mg/ml mitomycin C at each incision site.

RESULTS

A total of 18 patients were treated with bladder neck incision and mitomycin C injection. Preoperatively 4 (22%) patients presented with indwelling Foley catheters while 7 (39%) required a dilation schedule. At a median followup of 12 months (range 4 to 26) 13 patients (72%) had a patent bladder neck after 1 procedure, as did 3 (17%) after 2 procedures and 1 after 4 procedures. All of the patients presenting with a prior indwelling urethral catheter or requiring a dilation schedule had a stable, patent bladder neck.

CONCLUSIONS

Management of recurrent bladder neck contractures with radial urethrotomy combined with intralesional mitomycin C resulted in bladder neck patency in 72% of the patients after 1 procedure and in 89% after 2 procedures. Although early results are promising, longer followup and randomized, prospective studies are required to validate these findings.

Role of mitomycin C in reducing keloid recurrence: patient series and literature review

OBJECTIVE

To study the role of mitomycin C in reducing keloid recurrence.

STUDY DESIGN

Prospective, randomised, controlled trial.

SETTING

Tertiary care referral centre.

PATIENTS

Case series of 20 patients presenting with 26 pinna swellings, mostly following ear piercing.

INTERVENTIONS

We used the technique of surgical shave excision combined with topical application of mitomycin C and secondary wound healing, in all 26 pinnae.

RESULTS

Patients were followed up six to 24 months post-operatively. No recurrences were noted during this period.

CONCLUSION

Keloids are fibrotic lesions resulting from abnormal wound healing. The uncontrolled proliferation of normal tissue healing processes results in scarring that enlarges well beyond the original wound margins. Successful treatment of keloids remains a challenge because this disease process has a high propensity for recurrence. Various therapies have previously been reported, and success rates are highly variable. We believe that shave excision followed by topical mitomycin C application is a promising treatment option for the management of pinna keloids.

The emerging role of antineoplastic agents in the treatment of keloids and hypertrophic scars: a review

The management of keloids and hypertrophic scars continues to challenge health-care providers. Though both forms of pathologic scarring are distinct entities at the macro and microscopic level, their etiologies and treatment are often similar. Potential treatment approaches are progressing, and combinations of treatment options have been proposed in the literature with promising outcomes. The treatment evolution has reached a level where molecular therapeutic modalities are being investigated. Currently, no gold standard treatment exists. Overall success rates and patient satisfaction seem to be slowly climbing, but additional investigational studies must continue to be performed. Several studies have investigated antineoplastic agents, and there seems to be a marked improvement in rates of recurrence, patient satisfaction, and overall quality of scar when these agents are used. Intralesional injection and/or wound irrigation with interferon-a2b, interferon-g, mitomycin-C, bleomycin, or 5-fluorouracil seems to have a positive effect on the reduction of pathologic scars. There is mounting evidence that these drugs used alone or in combination therapy, have the potential to be an integral part of the treatment paradigm for hypertrophic scars and keloids.

A review of the effectiveness of antimitotic drug injections for hypertrophic scars and keloids

Hypertrophic scars and keloids are common problems after injury and cause functional and cosmetic deformities. A wide variety of treatments have been advocated for hypertrophic scars and keloids regression. Unfortunately, the reported efficacy has been variable. This article explores antimitotic drugs described in the literature such as steroid injection, 5-FU, mitomycin C, and bleomycin, which mainly target the fibroblasts in scar tissue, have been proposed as the effective modalities for scar treatment and scar prevention after surgery, but restricted due to possible side effects. The current accepted treatment for hypertrophic scar and keloid are combination therapy and the early treatment which could achieve better efficacy and less adverse effect.

Mitomycin C decreases the rate of stricture formation in caustic esophageal burns in rats

BACKGROUND

Although the incidence of caustic ingestion is declining, the management of caustic esophageal strictures remains a challenge. Although many agents have been tried experimentally to treat strictures, few have gained clinical application. The aim of this study was to investigate the influence of mitomycin C (MMC), which inhibits fibroblastic proliferation in treating delayed caustic esophageal strictures.

METHODS

Forty-two rats were allocated into 3 groups. Caustic esophageal burns were created as described by Gehanno. Group A was instilled only with saline. Group B was injured with 10% NaOH and left untreated. Group C was injured and received topical MMC at 0.04% concentration in the fourth week. At 56 days, stenosis index (SI), collagen deposition, and hydroxyproline content (HP) were determined in distal esophageal segments. Statistical analyses were performed.

RESULTS

The mean SI in group B was significantly higher than others (SI: 1.15 +/- 0.37 d/lum, P < .05). Collagen accumulation was highest in group B, followed by groups C and A, respectively. Collagen deposition in group C was statistically lower than group B (P < .018). The mean HP in group B was statistically higher than others (5.07 +/- 1.30 microg/mg tissue, P < .05), and similar between groups A and C (1.20 +/- 0.20, 1.91+/- 0.79, respectively, P = .73).

CONCLUSION

In the current study, MMC treatment ameliorated caustic esophageal stricture as reflected in the significantly lower SI. We conclude that MMC application is effective in the treatment of caustic esophageal strictures.

The effects of onion extract on hypertrophic and keloid scars

OBJECTIVE

To evaluate the therapeutic activity of topical onion extract in gel form on hypertrophic and keloid scars, focusing on problems such as elevation, redness, hardness, itching and pain.

METHOD

This comparative prospective study assigned 60 patients to three groups. Group I was treated with onion extract alone, group 2 with silicon gel sheet alone and 3 group with a combination of onion extract and silicon gel sheet.

RESULTS

In the group comparisons, a significant difference was observed at the end of six months in the colour parameter between group I and group 2 and in the height parameter between group I and group 3 (ANOVA post-hoc Tukey's test, p<0.01 and p<0.05 respectively). The onion extract was more effective in relation to scar colour, while the silicon gel sheet was superior in decreasing the height of scar (paired sample t-test, p<0.001). In addition, the most effective therapeutic results were obtained when the silicon gel sheet treatment was combined with onion extract in group 3.

CONCLUSION

Onion extract improved hypertrophic and keloids scars via multiple mechanisms. However, it was statistically ineffective in improving scar height and itching. For this reason, onion extract therapy should be used in combination with an occlusive silicon dressing to achieve a satisfying decrease in scar height.

The Effect of Topical Mitomycin C on Full-Thickness Burns

BACKGROUND

Burns result in substantial morbidity because of fibroblast proliferation and contracture. Mitomycin C is a chemotherapeutic agent known to suppress fibroblast proliferation. It is used in ophthalmologic disorders and reduces scarring in upper aerodigestive surgery. No study of the effect of mitomycin C on cutaneous burns has been performed. This study examined burn healing in the presence of topical mitomycin C by evaluation of wound appearance, contraction, and histology in a pig model.

METHODS

Standardized full-thickness burns were produced on the flanks of three pigs. One animal received no further therapy and was an external control. Two animals underwent placement of topical mitomycin C, 0.4 mg/ml, on selected burn sites for 5 minutes. This was repeated 2 and 4 weeks after injury. Evaluation was performed at 2 and 6 months using a clinical assessment scale and a visual analogue scale. Scar length and histologic analysis were also evaluated.

RESULTS

Clinical assessment scale and visual analogue scale scores showed improved appearance in the untreated external control wounds versus the untreated internal control and treated wounds (p < 0.001). Wound contraction was not significantly different between groups. Histologic characteristics between groups were similar except for epidermal hyperplasia, which was decreased in the untreated external control (p < 0.05) at 2 months after treatment.

CONCLUSIONS

Topical mitomycin C treatment of full-thickness burn wounds at 0.4 mg/cc for three courses does not improve, and may worsen, clinical appearance and scarring during early healing. There is no difference in histology during the long-term healing process. Scar contraction was unchanged.

Therapy of auricular keloids: review of different treatment modalities and proposal for a therapeutic algorithm

Keloids are abnormal wound reactions of connective tissue. Auricular keloids can develop as a result of, e.g., otoplasty, ear piercing, or skin trauma. A wide variety of therapeutic options exists, including surgery as primary treatment. Furthermore, there are medical, physical, radiotherapeutic and experimental options. The present paper focuses on the different techniques including the therapeutic outcome and quality rating for each chosen pathway. In addition to the experience of the university hospitals, a thorough review of the literature was performed in order to update and compare today's therapeutic options. Surgical techniques are customized to the lesion's specific localization and extent. They may include revision of otoplasty. With medical treatment, established modalities such as steroid injection have to be distinguished from experimental methods like interferon, 5-FU, verapamil, imiquimod, or mitomycin C. Radiation is generally accepted to be effective, especially applied accompanying surgery, but needs to be restricted due to possible side effects. Physical therapy, e.g., pressure in a variety of application modalities, has gained a profound position in the therapy of auricular keloids. The success rates of the different treatment modalities vary markedly, and the number of patients per study is considerably low. Resuming the results, a periodic follow-up and good patients' compliance are mandatory to early realize and treat auricular keloids. However, studies are needed to evaluate accepted and experimental therapies including larger number of patients.

Mitomycin C and endoscopic sinus surgery: where are we?

PURPOSE OF REVIEW

Mitomycin C has been used successfully in various ophthalmologic and, more recently, otolaryngologic procedures. Its modulation of fibroblast activity allows for decreased scarring and fibrosis. Several recent trials have examined the efficacy of mitomycin C in reducing synechia and stenosis following endoscopic sinus surgery.

RECENT FINDINGS

Basic science studies using fibroblast cell lines have demonstrated a dose-dependent suppression of activity with the use of mitomycin C. This is further supported by animal studies that have shown lower rates of maxillary ostial restenosis following application of mitomycin C. No human trial, however, has demonstrated a statistically significant impact of mitomycin C on the incidence of postoperative synechia or stenosis following sinus surgery. The limitations of the literature are discussed.

SUMMARY

The antiproliferative properties of mitomycin C may theoretically decrease the incidence of synechia and stenosis following endoscopic sinus surgery. Although this is supported by basic science studies and its successful use in other fields, the clinical evidence to date has not shown the application of mitomycin C to be effective in preventing stenosis after endoscopic sinus surgery. Future prospective studies are required before definitive conclusions can be made.

Application of topical mitomycin C to the base of shave-removed keloid scars to prevent their recurrence

BACKGROUND

Keloid scars are formed by over-activity of fibroblasts producing collagen and they cause significant morbidity both from their appearance and from their symptoms. Existing treatments are often unsatisfactory. Topical mitomycin C is known to inhibit fibroblast proliferation.

OBJECTIVES

To determine whether application of mitomycin C to the base of shave-removed keloids would prevent their recurrence.

METHODS

Ten patients had all or part of their keloid shave-removed. After haemostasis topical mitomycin C 1 mg mL(-1) was applied for 3 min. This application was repeated after 3 weeks. The keloids were photographed before treatment and the patients were reviewed every 2 months for a total of 6 months when a final photograph of the keloid site was taken. The patients and the Clinical Trials Unit staff scored the outcome on a linear analogue scale of 0-10, where 0 = disappointed and 10 = delighted. The pretreatment and 6-month post-treatment photographs were also assessed by two dermatologists who were not involved in the clinical trial.

RESULTS

Four of the 10 patients were delighted with the outcome of treatment and only one was disappointed. On average there was an 80% satisfied outcome.

CONCLUSIONS

This new treatment of keloids has been shown to be effective in the majority of patients but further studies are required to confirm this benefit.

Wound Healing: An Overview

Understanding wound healing today involves much more than simply stating that there are three phases: inflammation, proliferation, and maturation. Wound healing is a complex series of reactions and interactions among cells and "mediators." Each year, new mediators are discovered and our understanding of inflammatory mediators and cellular interactions grows. This article will attempt to provide a concise overview on wound healing and wound management.

Effects of Mitomycin-C on Normal Dermal Fibroblasts

OBJECTIVES

To evaluate the effects of mitomycin-C on the growth and autocrine growth factor production of human dermal fibroblasts from the face.

STUDY DESIGN

In vitro study using normal adult dermal fibroblast cell lines in a serum-free model.

METHODS

Cell cultures were exposed to 4 mg/mL, 0.4 mg/mL, 0.04 mg/mL, 0.004 mg/mL, and 0.0004 mg/mL concentrations of mitomycin-C solution. Cell counts were performed, and the cell-free supernatants were collected at 0, 1, 3, and 5 days after the initial exposure. Population doubling times were calculated and supernatants were quantitatively assayed for basic fibroblast growth factor (bFGF) and transforming growth factor (TGF)-beta1.

RESULTS

Continuous exposure to mitomycin-C caused fibroblast cell death by day 7 at all tested concentrations. A 4 minute exposure to mitomycin-C at 4 mg/mL caused rapid fibroblast cell death. A 4-minute exposure to mitomycin-C at either 0.4 mg/mL or 0.04 mg/mL resulted in decreased fibroblast proliferation. A 4 minute exposure to mitomycin-C at 0.4 mg/mL resulted in a marked increase in the production of both bFGF and TGF-beta1.

CONCLUSIONS

A clinically ideal concentration of mitomycin-C would slow fibroblast proliferation yet not cause cell death to allow for a wound healing response. Mitomycin-C 0.4 mg/mL for 4 minutes satisfies the above criteria in vitro.