Skin irritation

Evaluation of the medical devices benchmark materials in the controlled human patch testing and in the RhE in vitro skin irritation protocol

Several irritants were used in the in vitro irritation medical device round robin. The objective of this study was to verify their irritation potential using the human patch test (HPT), an in vitro assay, and in vivo data. The irritants were lactic acid (LA), heptanoic acid (HA), sodium dodecyl sulfate (SDS), Genapol® X-80 (GP), and Y-4 polymer. Dilute saline and sesame seed oil (SSO) solutions of each […]

Hydrophobic binary mixtures containing amphotericin B as lipophilic solutions for the treatment of cutaneous leishmaniasis

Cutaneous leishmaniasis, caused by Leishmania parasites, requires treatments with fewer side effects than those currently available. The development of a topical solution based on amphotericin B (AmB) was pursued. The considerable interest in deep eutectic solvents (DESs) and their remarkable advantages inspired the search for a suitable hydrophobic excipient. Various mixtures based on commonly used […]

Evaluation of skin irritation potentials of different cosmetic products in Turkish market by reconstructed human epidermis model

Human skin is a protective barrier against the toxic effects of cosmetics. Marketing of cosmetic products with ingredients tested on animals was prohibited in 2013. Since then, safety evaluation of cosmetic products is performed by using alternative in vitro toxicity tests. In vitro 3-D reconstructed human epidermis (RhE) tissue models are now used to define […]

Health safety of parabens evaluated by selected in vitro methods

Seven selected parabens (4 allowed, 3 banned in cosmetics) were tested in order to confirm and expand historical data on their toxicological properties and safety. The aim was to apply novel in vitro methods, which have been sufficiently technically and scientifically validated for the purposes of toxicological testing of chemicals. The study included several toxicological […]

Correlation of In Vitro and In Vivo Skin Irritation Assays in Medical Devices: A Case Study

Biocompatibility testing is moving away from animal-based assays in favor of technologically advanced and reliable in silico and in vitro alternative approaches. While irritation has traditionally been assessed in a rabbit animal model, validated reconstructed human epidermis(RhE) models have been introduced in ISO 10993-23:2021. This standard describes a step-wise approach to evaluating the potential for […]

Can Performance and Gentleness Be Reconciled? A Skin Care Approach for Sensitive Skin

People with self-reported sensitive skin may reluctantly use performing anti-ageing skin care products as it could elicit skin discomfort. We thus aimed to design and test an anti-ageing skin care routine that is suitable for people reporting sensitive skin. Key principles for developing products for sensitive skin were applied and formulas were screened for their […]

In Vitro and Clinical Safety Assessment of the Multiple W/O/W Emulsion Based on the Active Ingredients from Rosmarinus officinalis L., Avena sativa L. and Linum usitatissimum L.

The multiple W/O/W emulsion supplemented with the extracts of Rosmarinus officinalis L., Avena sativa L. and Linum usitatissimum L. was prepared in the study, its active compounds were determined by HPLC and its safety was evaluated in vitro by the means of reconstituted human skin model EpiDerm™ for the assessment of its irritation, phototoxicity and […]

Round robin study to evaluate the reconstructed human epidermis (RhE) model as an in vitro skin irritation test for detection of irritant activity in medical device extracts

Assessment of skin irritation is an essential component of the safety evaluation of medical devices. OECD Test Guideline 439 describes the use of reconstructed human epidermis (RhE) as an in vitro test system for classification of skin irritation by neat chemicals. An international round robin study was conducted to evaluate the RhE method for determination […]

In vitro evaluation of immunobiological activity of simple mannolipids

Immunomodulation, cytotoxicity and anti-cancer activity of selected amphiphilic non-ionic (thio)alkyl α-Dmannosides (with aglycone of C6-C12) were investigated in vitro in human cervix epitheloid carcinoma cell line HeLa, murine melanoma cancer cells B16, murine lymphocytic leukemia cell line L1210, murine fibroblast cell line NIH 3 T3 and murine macrophage cell line RAW 264.7. Toxicological studies revealed […]

Novel cytokine marker available for skin irritation testing of medical devices using reconstructed human epidermis models

In biological safety evaluation of medical devices, false-negative results have been observed during skin irritation testing using the reconstructed human epidermis (RhE) model when measuring cell viability as a single marker. Therefore, to improve testing accuracy, this study conducted a comprehensive survey and performance evaluation of cytokines to identify a second marker. In addition to […]

Pre-validation of an in vitro skin irritation test for medical devices using the reconstructed human tissue model EpiDerm™

Assessment of dermal irritation is an essential component of the safety evaluation of medical devices. Reconstructed human epidermis (RhE) models have replaced rabbit skin irritation testing for neat chemicals and their mixtures (OECD Test Guideline 439). However, this guideline cannot be directly applied to the area of medical devices (MD) since their non-toxicity assessment is […]

Reconstructed Human Epidermis Predicts Barrier-Improving Effects of Lactococcus lactis Emulsion in Humans

Background/Aims: The skin provides protection against chemical, physical, and biological stressors, yet the skin morphology changes over the course of life. These changes might affect the skin barrier function and facilitate the onset of age-related diseases. Since orally applied lactic acid bacteria ameliorate signs of aged and atopic skin, we investigated the effects of a […]

In vitro biocompatibility study approaches to evaluate the safety profile of electrolyzed water for skin and eye

Electrolyzed water (EW) is a widely used disinfectant agent with high oxidation–reduction potential (ORP). Although EW has been used in many areas, such as food hygiene, agriculture, and animal husbandry, the studies presented in the literature are not enough to clarify the toxic effects of EW. The aim of this study is, therefore, to produce […]

Hypoxia leads to abnormal epidermal differentiation via HIF-independent pathways

Atmospheric oxygen is important for the epidermis, as the skin epidermis is not greatly affected by blood circulation. Therefore, it is necessary to understand the effect of hypoxic signals on the epidermis as some environmental stimuli can induce skin hypoxia. Here, we investigated how hypoxia (1% O2) affected skin equivalents (SEs) and normal human epidermal […]

The EpiDerm Skin Irritation Test 3 (EpiDerm SIT)

Skin irritation is defined in vivo as the reversible damage to the skin following the application of a test chemical for up to 4 h [as defined by the United Nations (UN) Globally Harmonized System of Classification and Labeling of Chemicals (GHS)]. The potential of chemicals to induce skin irritation (hazard) is an important consideration in establishing […]

In Vitro Assessment of Skin Irritation Potential of Surfactant-based Formulations by Using a 3-D Skin Reconstructed Tissue Model and Cytokine Response

Summary — The personal care industry is focused on developing safe, more efficacious, and increasingly milder products, that are routinely undergoing preclinical and clinical testing before becoming available for consumer use on skin. In vitro systems based on skin reconstructed equivalents are now established for the preclinical assessment of product irritation potential and as alternative testing methods to […]

Application of Mattek In Vitro Reconstructed Human Skin Models for Safety, Efficacy Screening, and Basic Preclinical Research

During the past three decades, great progress has been achieved in the development of in vitro reconstructed human epidermal (RhE) tissue models. This technology is now available via various manufacturers of commercially available tissue models, and has provided opportunities for researchers worldwide to reduce or even completely avoid in vivo experimentation for screening and prediction of cutaneous […]

Antibacterial modification of an injectable, biodegradable, non-cytotoxic block copolymer-based physical gel with body temperature-stimulated sol-gel transition and controlled drug release

Biomaterials are being extensively used in various biomedical fields; however, they are readily infected with microorganisms, thus posing a serious threat to the public health care. We herein presented a facile route to the antibacterial modification of an important A-B-A type biomaterial using poly (ethylene glycol) methyl ether (mPEG)- poly(-caprolactone) (PCL)-mPEG as a typical model. […]

IN VITRO APPROACHES FOR PREDICTING IRRITATION POTENTIAL OF TOPICAL EXPOSURES TO THE SKIN AND EYES.

Outline: Focus on topical exposure toxicity measures …Skin ……Corrosion ……Irritation –Chemicals ……Mildness –Formulations …Eye ……Physiology and modes of action –eye irritation ……Human Reconstructed Tissues ………Ingredients ………Mild formulation assessment …BCOP ……Moderate formulation assessment histology Conclusions: Skin Irritation/Corrosion …Validated methods are in place for testing chemicals for corrosion and irritation (EU). …Methods for determining mildness of formulations […]

AN IN VITRO METHOD FOR SCREENING ANTI-IRRITANTS ON UV AND CHEMICALLY TREATED, RECONSTITUTED, THREE DIMENSIONAL HUMAN SKIN.

A great need exists in the cosmetics industry for in vitro screening methods that can provide accurate predictions of potential product or ingredient irritation. A variety of in vitro methods exist that utilize cell cultures, some of these focusing on the effects of irritants on specific cytokine release. However, these are not suitable for the […]

USE OF DIFFERENTIAL DISPLAY-POLYMERASE CHAIN REACTION TO IDENTIFY GENES SELECTIVELY MODULATED BY CHEMICAL ALLERGENS IN RECONSTITUTED HUMAN EPIDERMIS.

In the screening of topical drugs, cosmetics and other chemicals for human use, it is very important, both from a safety and an economic point of view, to have biological markers to discriminate irritant and allergic contact dermatitis that have different impacts on human health. Owing to their anatomical location, keratinocytes are among the first […]

IN VITRO AND IN VIVO COMPARISON OF DERMAL IRRITANCY OF JET FUEL EXPOSURE USING EPIDERM (EPI-200) CULTURED HUMAN SKIN AND HAIRLESS RATS.

This study by researchers at the Schools of Pharmacy at Florida A&M University and Auburn University demonstrated that Mattek’s EpiDerm human skin tissue equivalent can be used as an alternative to animals in evaluating the dermal irritation potential of several jet fuel formulations. The purpose of this study was to evaluate the EpiDerm™ in vitro […]

DEVELOPMENT OF AN IN VITRO MODEL FOR THE PREDICTION OF SKIN IRRITATION POTENTIAL.

Cytokines important to the inflammatory cascade were measured both at the level of transcription and secreted protein, from skin equivalents topically exposed to a panel of relevant consumer products. The response of a full thickness model, consisting of both keratinocytes and fibroblasts (Advanced Tissue Sciences’ SKIN2™), was compared to a keratinocyte only equivalent (Mattek’s Epi-Derm™) […]

EVALUATION OF PRO-INFLAMMATORY BIOMARKERS OF IRRITATION IN HUMAN SKIN MODEL USING MULTIPLEXED IMMUNOASSAY.

INITIAL IN VITRO SCREENING APPROACH TO INVESTIGATE THE POTENTIAL HEALTH AND ENVIRONMENTAL HAZARDS OF ENVIROX™ – A NANOPARTICULATE CERIUM OXIDE DIESEL FUEL ADDITIVE.

This study by scientists at Oxonica, Product Assessment & Regulatory Compliance, and SafePharm Laboratories Ltd. demonstrated that Mattek’s EpiDerm in vitro tissue model system can be used to determine the skin irritation potential of formulations containing nanoparticles. Nanotechnology is the new industrial revolution of the 21st Century as the various processes lead to radical improvements […]

EVALUATION OF RECONSTRUCTED HUMAN EPIDERMIS KITS FOR THE IN VITRO ASSESSMENT OF COSMETIC SAFETY.

Reconstructed human epidermis is one of the most promising tools for in vitro evaluation of cosmetics. In recent years, their availability as kits offered to users practical models for the assessment of safety and efficacy of ingredients and finished products. However, the evaluation of their reproducibility, reliability and the relevance of the data obtained with […]

THE USE OF STANDARDIZED HUMAN SKIN MODELS FOR CUTANEOUS PHARMACOTOXICOLOGY STUDIES.

Reconstructed skin and epidermis models are finding increasingly numerous applications in cosmetology and dermatology. In particular, they are currently employed to assess the tolerability and efficacy of raw materials and formulations, in conditions approaching those of normal use. Importantly, the use of such models greatly reduces the need for animal testing. Various models of reconstructed […]

RECONSTRUCTED HUMAN EPIDERMIS EQUIVALENTS.

Special Section. (See Mattek TR’s 276 thru 283.)

UPDATE ON VALIDATION STATUS AND INDUSTRY UTILIZATION OF NORMAL HUMAN 3D (NHU-3D) ANIMAL ALTERNATIVE MODELS.

Progress in in vitro tissue engineering over the last several decades has contributed to a significant decrease in animal use for industrial risk and safety assessment of products and ingredients. Mattek Corporation has a long-standing involvement in development, production and validation of animal alternative in vitro models produced from normal human cells (NHu-3D models). The […]

PRESENCE OF HYDROCORTISONE DRAMATICALLY AFFECTS CYTOKINE PRODUCTION FOLLOWING UV IRRADIATION IN 3-DIMENSIONAL SKIN MODEL EPIDERM.

Dating back to work originally done by Rheinwald and Green, hydrocortisone (HC) is commonly used in culture media for epithelial cells, especially keratinocytes. In the culture of EpiDerm™, a highly differentiated, three-dimensional model of the human epidermis, this additive is included in the culture media. However, HC is a glucocorticoid, known for its anti-inflammatory efficacy. […]

Skin irritation and potential efficacy of a novel compound for localized treatment of psoriasis

Psoriasis is a chronic condition characterized by formation of white scaly patches on the skin. Current treatment options include topical glucocorticoids which have several side effects. Pentaerythritol tetrakis (3,5-di-tert-butyl-4-hydroxyhydrocinnamate) (PTTC) is a cinnamate tetraester which may be used as a novel topical treatment for psoriasis with less side effects. The purpose of this study was […]

NON-ANIMAL METHODS FOR TOXICITY TESTING: SKIN IRRITATION/CORROSION.

Skin toxicity refers to the local toxic effects resulting from a topical exposure of the skin to a substance. Skin toxicities include skin irritation and skin corrosion. The Globally Harmonized System of Classification and Labeling of Chemicals (GHS) defines skin irritation as “the production of reversible damage to the skin following the application of a […]

EVALUATION OF EPIDERM™ AS A MODEL TO STUDY IRRITATION AFTER EXPOSURE TO VARIOUS ALIPHATIC HYDROCARBONS FOUND IN JET FUELS.

This study by scientists at Florida A&M University College of Pharmacy, Auburn University Harrison School of Pharmacy, and Mattek Corp. demonstrated that Mattek’s EpiDerm in vitro human skin tissue equivalent is an excellent in vitro alternative to animal testing for evaluating the skin irritation potential of chemicals and jet fuels. JP-8 has been recognized as […]

NEW PERSPECTIVES ON SKIN-COMPATIBLE DETERGENTS FOR SENSITIVE SKIN.

An interdisciplinary working group comprising manufactures of washing machines and household detergents (IKW/ZVEI) has studied whether or not household detergents today can provoke skin reactions. The results showed that modern technologies (washing machines and detergents) do not generally lead to higher levels of residues on washed textiles than the technologies of the 1980s. Consumer perception […]

THE USE OF Mattek EPIDERMAL EQUIVALENTS FOR PREDICTION OF IRRITATION POTENTIAL.

The need exists for a rapid, accurate in vitro screening protocol, predictive for human skin irritation in response to topically applied products. The EPI-100, EpiDerm™ Human Skin Model System produced by Mattek Corp. (Ashland, MA) is being investigated for this purpose. This system consists of normal, human-derived epidermal keratinocytes (NHEK), grown on permeable cell culture […]

PERMEABILITY AND CYTOTOXICITY OF MACROMOLECULE FROM NASAL FORMULATION USING EPIAIRWAY TISSUE MODEL.

Hydrophilic macromolecules such as proteins and peptides are poorly absorbed through the nasal mucosa. Nastech Pharmaceuticals has utilized a variety of techniques to improve the nasal absorption of macromolecules with emphasize on achieving safety as well as therapeutic efficacy. EpiAirway, an in vitro epithelial cell membrane model, was employed to screen Nastech formulations and marketed […]

DEVELOPMENT OF IN VITRO METHODS FOR EVALUATING THE EPIDERMAL AND DERMAL EFFECTS OF ALPHA HYDROXY AND AMIDES.

Several in vitro methods for their ability to replicate in vivo effects of selected alpha hydroxy acids and amides on the epidermis and dermis have been investigated. Cytotoxicity, prostaglandin release, morphology and histology on single cells and on tissue models were studied. Cytotoxicity, PGE-2 release in a commercial full skin model (ZK1300) correlated better with […]

PROGRAM TO REDUCE ANIMAL TESTING FOR EPA REGISTRATIONS OF ANTIMICROBIAL PRODUCTS.

This study by scientists at Proctor & Gamble, S.C. Johnson, the Institute for In Vitro Sciences (IIVS) and The Accord Group, in conjunction with the US EPA, documented how Mattek’s EpiDerm in vitro human skin tissue equivalent and EpiOcular in vitro human corneal tissue equivalent can be used to assess the dermal and eye irritation […]

PREDICTIVE TESTING: UNDERSTANDING THE ROLE OF IN VITRO AND IN VIVO TESTING.

Understanding predictive in vitro testing of topically applied materials is especially important to the pharmacologist who works with the skin since this technology is applied for basic research and product development. This exhibit presents information and data on traditional and relatively new in vitro assays, i.e. both human clinical data and innovative three dimensional, artificially […]

A COMPARISON OF THREE DIMENSIONAL HUMAN SKIN MODELS TO EVALUATE THE DERMAL IRRITATION OF SELECTED PETROLEUM PRODUCTS.

The in vitro evaluation of the dermal irritation potential of volatile or water insoluble petroleum products has generally proved difficult. Scientists at ARCO and Microbiological Associates utilized three human skin constructs (Living Skin Equivalent [LSE], Organogenesis, Inc., Cambridge, MA; Skin2 Model ZK1300, Advanced Tissue Sciences, La Jolla, CA; and EpiDerm™, Mattek Corporation, Ashland, MA) to […]

EVALUATION OF TWO IN VITRO HUMAN SKIN EQUIVALENTS (THE EPIDERM™ AND SKIN²™ MODEL ZK1300) FOR ASSESSING THE SKIN IRRITATION POTENTIAL OF PERSONAL CARE PRODUCTS AND CHEMICALS.

Living, three-dimensional human skin substrates were used to assess the relative skin irritation potential of selected chemicals and prototype shampoo formulations. Scientists at Clairol Inc. and Thomas Stephens Associates exposed two full-thickness skin equivalent models (EpiDerm™ from Mattek Corp. and Skin2™ from Advanced Tissue Sciences, Inc.) topically to the test materials for periods ranging from […]

COMPARISONS OF IN VITRO AND IN VIVO SKIN RESPONSES TO SURFACTANTS WITH A RANGE OF IRRITANCY POTENTIAL.

Scientists at Procter & Gamble Co. previously reported the development of a battery of endpoints in human skin cultures that correlate with human skin irritation responses to selected prototype surfactants. The purpose of the present study was to directly compare dose-response characteristics for surfactant-induced irritation in intact human skin exposed in vivo with the responses […]

INTER-AND INTRALABORATORY REPRODUCIBILITY OF A THREE DIMENSIONAL HUMAN EPIDERMAL MODEL – EPIDERM.

EpiDerm™ is a model of the human epidermis grown from normal human epidermal keratinocytes (foreskin-derived) seeded onto Millicell® CM (Millipore Corp., Bedford, MA) cell culture inserts. The inserts are placed at the air/culture medium interface allowing the cells to differentiate into a three dimensional model which consists of a basal layer of epidermal keratinocytes covered […]

LOT-TO-LOT VARIABILITY OF EPIDERM, AN EPIDERMAL MODEL FOR DERMAL IRRITANCY TESTING.

A model of the human epidermis, EpiDerm™, cultured from neonatal fore-skin-derived normal human epidermal keratinocytes (NHEK) was introduced by Mattek Corporation in April 1993. Using highly controlled tissue culture techniques, weekly batches of EpiDerm are produced and shipped domestically and internationally for dermal irritancy testing, percutaneous absorption studies, and basic skin research, amongst other uses. […]

EVALUATION OF EPIDERM FULL THICKNESS-300 (EFT-300) AS AN IN VITRO MODEL FOR SKIN IRRITATION.

This study by scientists at the Colleges of Pharmacy at Florida A&M University and Auburn University, and at Mattek Corp. demonstrated that Mattek’s EpiDerm-FT full thickness human skin tissue equivalent is an excellent alternative to the use of animals for skin irritation research, in part because it contains a dermal as well as an epidermal […]

DESIGN PRINCIPLES OF CHEMICAL PENETRATION ENHANCERS FOR TRANSDERMAL DRUG DELIVERY.

This study by researchers at the University of California at Santa Barbara demonstrated how Mattek’s EpiDerm human skin tissue equivalent can be used to measure the irritation potential of chemical penetration enhancers (CPEs) present in a large number of transdermal, dermatological, and cosmetic products. Chemical penetration enhancers (CPEs) are present in a large number of […]

INTRA- AND INTERLABORATORY REPRODUCIBILITY (ET-50) OF EPIDERM, AN IN VITRO MODEL FOR DERMAL IRRITANCY TESTING.

An in vitro model of the human epidermis, EpiDerm™, cultured from normal human epidermal keratinocytes (NHEK), was introduced by Mattek Corporation in April 1993. Using highly controlled tissue culture techniques, weekly batches of EpiDerm are produced for dermal irritancy testing, percutaneous absorption studies, and basic skin research. Histology, sterility, and the toxicological behavior are rigorously […]

LIPID AND ULTRASTRUCTURAL CHARACTERIZATION OF A NEW EPIDERMAL MODEL SHOWS GOOD CORRESPONDENCE TO NORMAL HUMAN EPIDERMIS.

A model of the human epidermis, EpiDerm, based on neonatal foreskin-derived normal human epidermal keratinocytes (NHEK), has recently been characterized by scientists at the University of Iowa College of Dentistry in terms of stratum corneum (SC) lipids and ultrastructure. Cultured using serum free media, the model allows determination of the effects of defined media additives […]

LIPID CHARACTERIZATION OF A NEW EPIDERMAL MODEL FOR SKIN IRRITANCY AND PENETRATION STUDIES.

A model of human epidermis, EpiDerm™, based on neonatal, foreskin-derived normal human epidermal keratinocytes (NHEK) has recently been characterized by scientists at the University of Iowa College of Dentistry in terms of stratum corneum lipids, ultrastructure, and barrier properties. Cultured using serum free media, the EpiDerm model allows determination of the effects of defined media […]

EVALUATION OF THE USEFULNESS OF 3-D MODELS OF RECONSTITUTED HUMAN SKIN AND EPIDERMIS IN APPLICATIONS OF REGULATORY SKIN TOXICOLOGY: PREVALIDATION, VALIDATION, CATCH-UP VALIDATION, AND REGULATORY ACCEPTANCE.

In 1991 we evaluated a model of full human skin (Skin2, ATS, La Jolla) for phototoxicity testing. The test developed showed promising results as an adjunct to a test performed with Balb/c 3T3 cells. While it detected acute phototoxins correctly, it classified those chemicals negative, that are known photoallergic in humans, but are not phototoxic […]

MODULATION OF CYTOKINE MESSAGE IN THE EPIDERM IN VITRO SKIN MODEL FOLLOWING TREATMENT WITH CONTACT ALLERGENS AND SKIN IRRITANTS.

Previous studies have demonstrated that EpiDerm™ (Mattek Corporation) in vitro skin model constitutively expresses message for several cytokines (Limardi et al., 1996 JID 106, 939). The objective of research presented here is to assess the ability of irritants and contact allergens to modulate cytokine message in the EpiDerm model. Total RNA was isolated at 2 […]

RECONSTRUCTED SKIN KITS: REPRODUCIBILITY OF CUTANEOUS IRRITANCY TESTING.

The aim of this study was to determine the reproducibility of data obtained from in vitro irritation testing using three industrial reconstructed human epidermis models, EpiDerm™, Episkin™ and SkinEthic(R), and one in-house model developed at Wella/Cosmital. A common protocol was established based on the measurement of cytotoxicity in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and […]

A REPRODUCIBLE, STRUCTURALLY APPROPRIATE SKIN MODEL FOR DERMAL IRRITANCY AND EFFICACY TESTING.

The ability to determine, in vitro, the efficacy and irritancy of materials contacting the skin critically depends on the accuracy of the skin model in emulating native epidermis’ structure and biochemistry. In addition, for any toxicology or efficacy model to be useful, it is important to know that the model is reproducible both within a […]

PREDICTIVE ABILITY OF RECONSTRUCTED HUMAN EPIDERMIS EQUIVALENTS FOR THE ASSESSMENT OF SKIN IRRITATION OF COSMETICS.

The goal of this study by researchers at Cosmital SA (Wella AG) and L’Oreal (Life Sciences Research, Centre) was to examine the concordance between human in vivo and in vitro skin irritation classifications of cosmetic products and to evaluate the correlations between the different parameters. For that purpose, 22 formulations from product development test series, […]

PROTEOMIC AND MICROARRAY INVESTIGATION TO IDENTIFY POTENTIAL IN VITRO ENDPOINTS FOR SKIN IRRITATION.

There is a need to investigate the mechanistic basis of the human skin irritation response if relevant in vitro test systems for the predictive identification of skin irritation are to be developed. The aim of this work was to identify proteins (and genes encoding proteins) which may be regulated in response to skin irritation, following […]

IDENTIFICATION OF POTENTIAL IN VITRO ENDPOINTS FOR SKIN IRRITATION USING PROTEOMIC AND MICROARRAY ANALYSIS.

Understanding the mechanistic basis of the human skin irritation response is key to the development of relevant in vitro test systems for the predictive identification of skin irritation hazards. Recent progress in the development of proteomic and microarray technologies means that tools for the identification and investigation of important biochemical events in the processes of […]

GENE EXPRESSION ANALYSIS OF EPIDERM™ FOLLOWING EXPOSURE TO SLS USING cDNA MICROARRAYS.

There is a need to investigate the mechanistic basis of the human skin irritation response if relevant in vitro test systems for the predictive identification of skin irritation hazards are to be developed. Recent progress in genomics technologies mean that tools for the identification and investigation of important biochemical events in the processes of skin […]

RECONSTRUCTED HUMAN SKIN EQUIVALENTS-THEIR VALUE FOR SCREENING OF SKIN IRRITATION.

Advances in techniques for culturing human skin cells have led to the development of reconstructed human skin equivalents that closely resemble native human skin. These in vitro models offer a variety of approaches to investigate wound healing, skin ageing, pigmentation, skin penetration, transdermal drug delivery, cutaneous metabolism and toxicity. Skin corrosion and irritation due to […]

CHARACTERIZATION AND COMPARISON OF RECONSTRUCTED SKIN MODELS: MORPHOLOGICAL AND IMMUNOHISTOCHEMICAL EVALUATION.

Reconstructed human skin equivalents are currently being investigated as in vitro models for the prediction of human skin toxicity and irritation responses. Three different industrial reconstructed skin models (EpiDerm, Episkin and SkinEthic) and one in-house equivalent were characterized and compared using light microscopy, immunohistochemistry and reduction of (3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyl tetrazolium bromide) (MTT). Their inter- and intra-batch […]

USE OF DIFFERENTIATED EPIDERMAL CULTURES FOR THE EXAMINATION OF INFANT-FECES-INDUCED SKIN IRRITATION.

Infant feces (BM) is known to possess a multitude of skin irritants. The aim of this study was to examine an in vitro model for BM-induced skin irritation, and determine if BM-induced skin irritation can be patterned in the laboratory. Infant BM was examined by diluting in water as individual samples or by pooling samples […]

IL-1α AND IL-1ra SECRETION FROM EPIDERMAL EQUIVALENTS AND THE PREDICTION OF THE IRRITATION POTENTIAL OF MILD SOAP AND SURFACTANT-BASED CONSUMER PRODUCTS.

Scientists at Johnson & Johnson Consumer Products and Neutrogena Corp. previously evaluated the measurement of viability and cytokine release from skin equivalents for predicting the skin irritation potential of topically applied surfactants, and demonstrated that IL-1a and interleukin-1 receptor antagonist (IL-1ra) release from epidermal skin equivalents correlates with skin irritation potential. In this study, the […]

THE INFLUENCE OF THE RESPONSE OF SKIN EQUIVALENT SYSTEMS TO TOPICALLY APPLIED CONSUMER PRODUCTS BY EPITHELIAL-MESENCHYMAL INTERACTIONS.

A number of diverse in vitro model systems have been employed for the prediction of irritation potential of test articles. Monolayer systems have proven to be useful for preliminary screening but are not always capable of distinguishing mild effects or adaptable to fully formulated product. Three-dimensional reconstructed skin equivalents integrate cellular toxicity with the kinetics […]

HUMAN IN VITRO AND IN VIVO CUTANEOUS RESPONSES TO SOAP SUSPENSIONS: ROLE OF SOLUTION BEHAVIOR IN PREDICTING POTENTIAL IRRITANT CONTACT DERMATITIS.

Over the years a number of methods have been developed to assess the potential contact irritancy of cosmetic-related surfactants. These methods include in vitro exposure using skin equivalent cultures, proteins, enzymes, etc. These methods are exaggerated in so far as the time of exposure, concentration of material tested, and/or material composition do not represent typical […]

COMPARISON OF IN VITRO AND IN VIVO HUMAN SKIN RESPONSES TO CONSUMER PRODUCTS AND INGREDIENTS WITH A RANGE OF IRRITANCY POTENTIAL.

Human skin equivalent cultures were investigated as possible pre-clinical skin irritation screens to aid safety assessments for chemicals and product formulations, and to facilitate design of safe and efficient human studies. In vitro responses in human skin equivalent cultures were compared directly to in vivo human skin responses from historic or concurrent skin tests for […]

DEVELOPMENT OF AN IN VITRO METHOD FOR SCREENING ANTI-IRRITANTS.

The development of an in vitro method for testing unknown anti-irritant ingredients can provide preliminary estimate of material safety and it is fast and economical before testing on humans. We utilized the Mattek EpiDerm skin model and a primary culture of keratinocytes to screen a variety of anti-irritants. EpiDerm partially mimics human skin morphologically and […]

EFFECT OF A NEW BOTANICAL EXTRACT BASED ON THE RED ALGAE, PIKEA ROBUSTA, ON IN VIVO REDUCTION OF SURFACTANT-INDUCED SKIN IRRITATION.

Through millions of years of evolution, organisms have developed various biochemical mechanisms to combat environmental pollutants and insure cell viability. Today, we exist under a constant barrage of damaging elements. Some are external and environmental; some are internal and result from natural metabolic processes. These processes result in the formation of dangerous free radical species […]

EVALUATION OF A NEW ALTERNATIVE TO PRIMARY DRAIZE SKIN IRRITATION TESTING USING THE EPIDERM SKIN MODEL.

EpiDerm™ is a commercially available human skin model consisting of normal human-derived epidermal keratinocytes (NHEK), which have been cultured to form a multilayered, highly differentiated model of the human epidermis. We evaluated this model as an alternative to the primary Draize skin irritation test using rabbits. Eighteen cosmetic products were tested using a new assay […]

ASSESSMENT OF HUMAN SKIN IRRITATION: VALIDATION OF IN VITRO MODELS.

BIOCONVERSION OF TOCOPHERYL ACETATE TO TOCOPHEROL IN HUMAN SKIN ORGAN CULTURE MODELS.

There is substantial interest in delivering the antioxidant benefits of vitamin E (tocopherol) to the skin. Since free tocopherol is inherently unstable, it is usually delivered to the skin in the form of tocopheryl acetate. The premise behind this approach is that the skin’s enzymes (esterases/lipases) would bioconvert the pro-vitamin E to the active vitamin. […]

USE OF PROTEOMIC TECHNOLOGIES FOR DISCOVERY OF NEW MARKERS OF SKIN IRRITATION IN VITRO.

Analysis of epidermal proteins from irritant-treated in vitro epidermal models by proteomics is a promising approach to detect new markers of human skin irritation. These data provide a more comprehensive understanding of the mechanisms involved in the skin irritation response. It is possible that some of these may provide novel markers of skin irritation.

SKIN IRRITATION POTENTIAL OF SURFACTANT MIXTURES: USING RELEVANT DOSES IN IN VITRO SYSTEMS.

Simple in vitro cell culture methods are often inappropriate for investigating the cytotoxicity of high concentration test substances. The relevance of these assays for assessing skin irritation potential substances such as surfactants or surfactant mixtures, where the toxicity of the substance is related to its physicochemical state which is in turn dependent on its concentration, […]

SCREENING SOFT MATERIALS FOR THEIR EFFECT ON SKIN BARRIER FUNCTION BY HIGH THROUGHPUT EXPERIMENTATION.

Some of the challenges in applying high throughput experimentation (HTE) to materials in contact with natural media or tissues are outlined, with an emphasis on soft materials applied to biological surfaces, such as skin. We overview approaches to soft materials development and to assaying, in high throughput, how such soft materials affect skin barrier properties […]

ASSESSMENT OF SKIN ABSORPTION AND IRRITATION POTENTIAL OF ARACHIDONIC ACID AND GLYCERYL ARACHIDONATE USING IN VITRO DIFFUSION CELL TECHNIQUES.

Arachidonic acid (AA), a precursor of pro-inflammatory mediators, and its glycerin ester, glyceryl arachidonate (GA), are reportedly used in cosmetic products. In vitro skin penetration of AA and GA and GA’s ester hydrolysis was determined in flow-through diffusion cells. AA penetration with human and rat skin was 19.5% and 52.3% of the applied dose respectively, […]

NON-ANIMAL METHODS FOR TOXICITY TESTING: THE WAY FORWARD FOR IN VITRO SKIN IRRITATION TESTING.

A major milestone for in vitro skin irritation testing was achieved with the recent release of the Statement on the Validity of In-Vitro Tests for Skin Irritation by the European Centre for the Validation of Alternative Methods (ECVAM) Scientific Advisory Committee (ESAC). The statement endorsed the use of in vitro skin models and the MTT […]

IRRITANCY AND ALLERGIC RESPONSES INDUCED BY TOPICAL APPLICATION OF ORTHO-PHTHALALDEHYDE.

Although ortho-phthalaldehyde (OPA) has been suggested as an alternative to glutaraldehyde for the sterilization and disinfection of hospital equipment, the toxicity has not been thoroughly investigated. The purpose of these studies was to evaluate the irritancy and sensitization potential of OPA. The EpiDerm Skin Irritation Test was used to evaluate in vitro irritancy potential of […]

FURTHER DEVELOPMENT OF AN EPIDERM™ IN VITRO SKIN IRRITATION TEST FOR THE GLOBALLY HARMONIZED SYSTEM (GHS-SIT) OF CLASSIFICATION AND LABELING OF CHEMICALS.

Determination of skin irritation potential is an international regulatory requirement to ensure safe handling, packaging, labeling and transport of chemicals and evaluation of cosmetics and household products. Recent REACH legislation and a ban on animal testing for cosmetics have heightened the need for validated in vitro SITs. A UN treaty endorsed by the US, EU, […]

IN VITRO SKIN IRRITATION TESTING: IMPROVING THE SENSITIVITY OF THE EPIDERM SKIN IRRITATION TEST PROTOCOL.

This paper details the effort by Mattek scientists to increase the sensitivity of the Skin Irritation Test (SIT) method based on Mattek’s EpiDerm in vitro 3-D human skin tissue equivalent. This effort led to the EpiDerm SIT method being validated by ECVAM as a full replacement for the rabbit skin irritant test in November 2008. […]

AN IN VITRO SKIN IRRITATION TEST (SIT) USING THE EPIDERM RECONSTRUCTED HUMAN EPIDERMAL (RHE) MODEL. (VIDEO Protocol)

This peer-reviewed, PubMed-indexed VIDEO technical article produced by scientists at Mattek Corp. and published in JoVE (Journal of Visualized Experiments) provides detailed instructions on how to perform the ECVAM-Validated EpiDerm Skin Irritation Test (SIT) Method, a stand-alone full replacement for traditional animal-based skin irritation tests. NOTE: This 20 MINUTE video protocol is ONLY to be […]

FOLLOW-UP VALIDATION OF THE EPIDERM SKIN IRRITATION TEST (SIT): RESULTS OF A MULTI-CENTRE STUDY OF TWENTY REFERENCE TEST SUBSTANCES.

This multi-center validation study performed by scientists at BfR (ZEBET), BASF SE, the Institute for In Vitro Sciences, Inc., the Centre for Alternative and Complementary Methods to Animal Testing (zet–LSL) and Mattek Corp. demonstrated that the modified Skin Irritation Test (SIT) based on Mattek’s EpiDerm in vitro human skin tissue equivalent can be used to […]

COMPARISON OF HUMAN PATCH TEST AND 3D HUMAN SKIN MODEL RESULTS WITH CLASSIFICATION OF CHEMICALS BASED ON RABBIT DRAIZE TEST.

As stated in the “Conclusions” section, this study by scientists at the National Institute of Public Health (CZ), St. John’s Institute of Dermatology, Unilever SEAC, ZEBET, and Mattek Corp. demonstrated that in vitro 3D models derived from human skin cells (Mattek’s EpiDerm), if used in appropriate test designs and optimized by reference to human hazard […]

A REPRODUCIBLE SKIN MODEL FOR DERMAL SAFETY AND EFFICACY TESTING.

The utility of any toxicological test system or method critically depends on the short and long term reproducibility of the method. Over the past 6 years, histological observations and quantitative quality control test methods utilizing the MTT assay have established a high level of intra-lot and inter-lot reproducibility for Mattek’s organotypic skin model, EpiDerm™. Interestingly, […]

IN VITRO SKIN IRRITATION TEST: INCREASING THE SENSITIVITY OF THE EPIDERM SKIN IRRITATION PROTOCOL EVALUATED IN THE ECVAM SKIN IRRITATION VALIDATION STUDY.

This study by scientists at Mattek Corp. demonstrated that a modification of the common Skin Irritation protocol that extended the exposure time from 15 minutes to 60 minutes for Mattek’s EpiDerm in vitro human skin tissue model produced a significant increase in sensitivity without decreasing the specificity of the method. During 2001-2004, refined EPISKIN and […]

A REPRODUCIBLE, STRUCTURALLY APPROPRIATE SKIN MODEL FOR DERMAL SAFETY AND EFFICACY TESTING.

The ability to determine, in vitro, the safety and efficacy profile for a material contacting the skin critically depends on the skin model’s structure and biochemistry. In addition, to be useful, the model must have a high level of intra-lot and inter-lot reproducibility. For this reason, the structure, biochemical nature, and reproducibility of the organotypic […]

AN IN VITRO SYSTEM FOR PREDICTING SKIN IRRITATION OF LIQUID ANTIPERSPIRANTS.

This study by scientists at Procter & Gamble demonstrated the ability to use Mattek’s EpiDerm in vitro human tissue equivalent as a preclinical test to confirm the mildness of prototype liquid antiperspirant formulations prior to beginning human clinical evaluations. Topical skin care products differ substantially in their composition, yet all need to be acceptably mild […]

IN VITRO HUMAN SKIN IRRITATION TEST FOR EVALUATION OF MEDICAL DEVICE EXTRACTS.

Purpose: The aim of this study was to determine if the EpiDerm™ reconstructed human skin model (Mattek Corp.) could be an acceptable alternative to the ISO 10993-required rabbit skin irritation test for assessing medical device biocompatibility. Eleven medical device polymers were tested. Four extracts were prepared per polymer, two each with saline and sesame oil; half […]

PROTEOMIC ANALYSIS OF THE RESPONSE OF EPIDERM™ CULTURES TO SODIUM LAURYL SULPHATE.

This study by researchers at Unilever’s Safety and Environmental Assurance Centre (SEAC) demonstrated how Mattek’s EpiDerm in vitro human skin tissue equivalent was used to identify a number of proteins that could be used as general markers for skin irritation. Scientists at Unilever’s Safety and Environmental Assurance Centre (UK) performed an analysis of EpiDerm™ cultures […]

EVALUATION OF AN IN VITRO HUMAN SKIN IRRITATION TEST FOR USE WITH MEDICAL DEVICE EXTRACTS

In accordance with ISO 10993, the rabbit skin irritation test is used to assess medical device biocompatibility, however, this method is time-consuming and expensive.  Our study’s goal was to determine if the EpiDerm™ reconstructed human skin model (Mattek Corp.) could be an acceptable alternative. To that end, eleven medical device polymers and adhesives were selected […]

USE OF HUMAN SKIN EQUIVALENT CULTURES FOR COSMETIC BENEFIT SCREENING.

This study by scientists at Procter and Gamble and CyberDERM demonstrated that Mattek’s EpiDerm fully developed and EpiDerm-201 underdeveloped in vitro human skin tissue equivalents, and EpiOcular in vitro human corneal tissue equivalent could be used to develop methodologies for measurement of transepidermal water loss (TEWL) from human epithelial tissue equivalent cultures, and that TEWL […]

CLASSIFICATION AND LABELING OF INDUSTRIAL PRODUCTS WITH EXTREME PH BY MAKING USE OF IN VITRO METHODS FOR THE ASSESSMENT OF SKIN AND EYE IRRITATION AND CORROSION IN A WEIGHT OF EVIDENCE APPROACH.

Classification and labeling of products with extreme pH values (62 or P11.5) is addressed in chemicals legislation. Following determination of pH and alkaline/acid reserve, additional in vitro tests are needed, especially to substantiate results less than corrosive. However, only limited experience with the practical application of in vitro methods to determine appropriate classifications for pH […]

IN VITRO ASSESSMENT OF SKIN IRRITATION POTENTIAL OF SURFACTANT BASED FORMULATIONS USING 3-D SKIN RECONSTRUCTED TISSUES AND CYTOKINE EXPRESSION ANALYSIS.

A goal of personal care products manufacturers is to develop increasingly milder formulations. To this end, reproducible  in vitro systems can accurately assess the irritation potential of the products, thus avoiding the use of animals for  testing. The three-dimensional EpiDermTM model (Mattek Corp.) provides a testing platform for Johnson & Johnson’s  skin irritation assessment program […]

MEETING REQUIREMENTS OF OECD TG 404 FOR IN VITRO SKIN IRRITATION TESTING: REPRODUCIBILITY OF EPIDERM SKIN IRRITATION TEST (EPIDERM-SIT) FOLLOWING ECVAM VALIDATION AND ACCEPTANCE AS A FULL REPLACEMENT METHOD.

In autumn 2007, an international validation study was performed to evaluate the reproducibility and confirm the predictive ability of the EpiDerm Skin Irritation Test (SIT) method (1, 2). In November 2008, ECVAM endorsed the EpiDerm SIT as a full replacement method for the in vivo rabbit skin irritation test. As reflected draft OECD guidelines for […]

ENSURING QUALITY OF IN VITRO ALTERNATIVE TEST METHODS: ISSUES AND ANSWERS.

This report by scientists at the US EPA, the US Consumer Product Safety Commission, the European Center for the Validation of Alternative Methods (ECVAM) and the Institute for In Vitro Sciences (IIVS) discussed the importance of having specific quality control safeguards in place during and long after formal in vitro test method validation is completed, […]

EVALUATION OF A TISSUE ENGINEERED HUMAN SKIN EPIDERM 3-D CULTURE AS A MODEL TO STUDY IRRITATION AFTER JET FUEL EXPOSURE.

This study by researchers at Florida A&M University demonstrated that Mattek’s EpiDerm in vitro human skin tissue equivalent is a “valuable model to evaluate the skin irritation potential of jet fuels and hydrocarbon chemicals”. The purpose of the present study was to evaluate human skin Epiderm™ 3-D culture, EPI-200 (Mattek Corp, Ashland, MA) as a […]

IN VITRO AND HUMAN TESTING STRATEGIES FOR SKIN IRRITATION.

Prior to the manufacture, transport, and marketing of chemicals or products, it is critical to assess their potential for skin toxicity (corrosion or irritation), thereby protecting the worker and consumer from adverse skin effects due to intended or accidental skin exposure. Traditionally, animal testing procedures have provided the data needed to assess the more severe […]

STRATEGIES FOR THE ASSESSMENT OF ACUTE SKIN IRRITATION POTENTIAL.

The manufacture, transport, and marketing of chemicals and finished products requires the prior toxicologic evaluation and assessment of skin reactivity (corrosion and irritation) that may result from intended or accidental skin exposure. Procedures for the skin testing of new chemicals and finished products is rapidly evolving in the face of technologic advancements and political pressures. […]

ALTERNATIVE METHODS FOR SKIN IRRITATION TESTING: THE CURRENT STATUS.

The ECVAM Skin Irritation Task Force was established in November 1996, primarily to prepare a report on the current status of the development and validation of alternative tests for skin irritation and corrosion and, in particular, to identify any appropriate non-animal tests for predicting human skin irritation which were sufficiently well-developed to warrant ECVAM supporting […]

INCORPORATION OF RECONSTRUCTED HUMAN EPIDERMAL TISSUES INTO A CORPORATE TOXICOLOGY LABORATORY: USE OF IN VITRO TEST DATA FOR DIVERSE SAFETY AND RISK ASSESSMENT APPLICATIONS.

The 3M Strategic Toxicology Laboratory (STL) is an internal corporate resource providing toxicology support to 3M businesses. An objective in the STL is to routinely incorporate in vitro test methods, with a recent focus on the use of reconstructed human epidermis (RhE) tissues.. The first model utilized has been EpiDerm™, which is currently validated for […]

LONG TERM REPRODUCIBILITY OF EPIDERM, AN EPIDERMAL MODEL FOR DERMAL TESTING AND RESEARCH.

This technical reference summarizes Mattek’s 10-plus YEAR EpiDerm tissue reproducibility data. Long-term reproducibility is important not only to Mattek Customers, but also to European (ECVAM) and US (ICCVAM) regulators. Regulators constantly stress the need for superior reproducibility of in vitro tissue equivalents, not only during a specific validation program, but also long after the initial […]

HUMANE ENDPOINTS AND ACUTE TOXICITY TESTING.

Evidence of acute toxicity for specific materials was originally provided using large numbers of animals in tests that often resulted in pain, suffering, and/or death to the experimental subjects. Recent research has been directed toward development of alternatives that remove or significantly reduce these effects while providing data indicative of the acute toxicity of the […]

THE Mattek STORY – HOW THE THREE Rs PRINCIPLES LED TO 3-D TISSUE SUCCESS!

FRAME, the UK-based Fund for the Replacement of Animals in Medical Experiments, asked Mattek to contribute an article to a special edition of ATLA, FRAME’s scientific journal, commemorating FRAME’s 40th anniversary. FRAME asked Mattek to focus the article on the successful development of our in vitro 3-D tissues, produced from normal (non-transformed) human cells, as […]

DEVELOPMENT OF AN IN VITRO CORROSION/IRRITATION PREDICTION ASSAY USING THE EPIDERM™ SKIN MODEL.

This study by scientists at Covance Laboratories and the University of York demonstrated that Mattek’s EpiDerm in vitro human skin tissue equivalent can be used to accurately predict the dermal corrosivity and skin irritation potential of 12 test chemicals. A validation of the in vitro skin corrosion method using the EpiDerm™ skin model was performed […]

RECONSTITUTED 3-DIMENSIONAL HUMAN SKIN, A NEW IN VITRO MODEL FOR SKIN CARCINOGENESIS STUDY.

EpiDerm (Mattek Co., MA) is a newly developed reconstituted human skin equivalent that exhibits human skin-like morphological and growth characteristics. It has been utilized to evaluate the cytotoxicity and irritant potential of various cosmetic and household products. In this study, we found that EpiDerm can also be used to evaluate the genotoxicity of carcinogenic agents […]

ASSESSMENT OF PHOTOTOXICITY, SKIN IRRITATION, AND SENSITIZATION POTENTIAL OF POLYSTYRENE AND TiO2 NANOPARTICLES.

The human skin equivalent model (HSEM) is well known as an attractive alternative model for evaluation of dermal toxicity. However, only limited data are available on the usefulness of an HSEM for nanotoxicity testing. This study was designed to investigate cutaneous toxicity of polystyrene and TiO2 nanoparticles using cultured keratinocytes, an HSEM, and an animal […]

USE OF NORMAL HUMAN 3D (NHU-3D) TISSUE MODELS (EPIDERM™, EPIAIRWAY™) FOR NANOTOXICOLOGY APPLICATIONS

Nanomaterials are increasingly utilized in numerous commercial applications where dermal contact, inhalation, or oral ingestion is likely. However, their toxicological properties are largely unknown. Potential adverse effects of nanoparticle exposure include allergenicity, cytotoxicity, and genotoxicity. Nanomaterials may enter the body by interacting with, and eventually crossing, epithelial barriers including skin, airway, and intestinal epithelium. Once […]

ASSESSMENT OF DERMAL TOXICITY OF NANOSILICA USING CULTURED KERATINOCYTES, A HUMAN SKIN EQUIVALENT MODEL AND AN IN VIVO MODEL.

This study by researchers at Korea University College of Medicine and the National Institute of Toxicological Research (Korea) demonstrated how Mattek’s EpiDerm in vitro 3-D human skin tissue equivalent can be used to test the skin irritation potential of nanosilica and “provided more useful screening data than the conventional cell culture model on the relative […]

OXIDATIVE STRESS AND INFLAMMATORY RESPONSE IN DERMAL TOXICITY OF SINGLE-WALLED CARBON NANOTUBES.

This study by researchers at PPRB/NIOSH, West Virginia University and the University of Pittsburgh demonstrated that Mattek’s EpiDermFT full-thickness in vitro 3-D human skin tissue equivalent can be used to measure the dermal toxicity of single-walled carbon nanotubes (SWCNT). Single-walled carbon nanotubes (SWCNT) represent a novel material with unique electronic and mechanical properties. The extremely […]

NEW EPIDERMAL MODEL FOR DERMAL IRRITANCY TESTING.

A model of the human epidermis, EpiDerm™, based on neonatal, foreskin-derived normal human epidermal keratinocytes (NHEK) has been developed over the past 18 months at Mattek Corporation. Cultured in easily handled Millicell® CM (Millipore Corp.) cell culture inserts, the model allows application of liquid and solid test materials (potential dermal irritants) directly to the stratum […]

EYE AND SKIN IRRITATION IN 3-D HUMAN TISSUE CONSTRUCTS USING MTT AND ATP ENDPOINTS.

This study by scientists at Beauty Avenues and the Institute for In Vitro Sciences (IIVS) demonstrated that Mattek’s EpiDerm in vitro 3-D human skin tissue equivalent and EpiOcular in vitro 3-D human corneal tissue equivalent can be used, if/when necessary, with the ATP tissue viability assay in addition to the industry-standard MTT tissue viability assay. […]

MICROARRAY ANALYSIS OF GENE EXPRESSION FOLLOWING EXPOSURE TO SKIN IRRITANTS.

Understanding of the mechanistic basis of the human skin irritation response is key to the development of relevant in vitro test systems for the predictive identification of skin irritation hazards. Recent progress in genomic technologies means that tools for the identification and investigation of important biochemical events in the processes of skin irritation are now […]

EVALUATION OF EPIDERM FULL THICKNESS-300 (EFT-300) AS AN IN VITRO MODEL FOR SKIN IRRITATION: STUDIES ON ALIPHATIC HYDROCARBONS.

This study by scientists at Florida A&M University, Auburn University and Mattek Corp. demonstrated that Mattek’s EpiDermFT full-thickness in vitro 3-D human skin tissue equivalent is an excellent in vitro model for predicting in vivo irritation and understanding the structural activity relationship of saturated aliphatic hydrocarbons.The aim of this study was to understand the skin […]

ASSESSMENT OF THE IRRITATION POTENTIAL OF TOPICAL SKIN ANTISEPTICS BY IN VIVO AND IN VITRO METHODS.

The development of an in vitro irritation assay producing results which correlate well with those obtained from in vivo animal studies would be a valuable tool for the evaluation of topical products. Human skin equivalent cultures are currently used as in vitro models to predict the topical irritation potential of actives, excipients, and formulations. These […]

IN VITRO SCREENING TECHNIQUES IN DERMATOLOGY.

To avoid skin irritation and allergies from cosmetic products, the raw materials should be screened during product development. In vivo screening techniques are best. The author describes two in vitro models (cell culture and living skin equivalent) and several in vitro tests (percutaneous absorption, toxicity, melanogenesis, wound healing, antiaging, and cell proliferation and differentiation).

TESTING AND IMPROVEMENT OF RECONSTRUCTED SKIN KITS IN ORDER TO ELABORATE EUROPEAN STANDARDS: FIRST RESULTS.

Cosmetics, safety testing, Cutaneous irritancy, Cutaneous irritation, Cutaneous metabolism, Cutaneous toxicity, Cytoplasmic enzymes, Dermal absorption, Dermal irritancy, Dermal irritancy testing, Dermal irritation, Dermal penetration, Dermal permeation, ECVAM, EpiDerm, EpiSkin, European standards, Glutamate-oxaloacetate transferase, Glutathione-S-transferase, IL-1a, Interleukin (IL), Lactate dehydrogenase, Lauric acid, MTT, MTT ET-50 tissue viability assay, MTT assay, Mannitol, Metabolism, NADPH quinone reductase, Penetration, […]

CYTOKINE AND LIPID MEDIATOR RELEASE FROM IN VITRO SKIN MODELS FOLLOWING DETERGENT TREATMENT OR PHYSICAL WOUNDING.

The purpose of the present work is to characterize two in vitro skin mod-els with regard to release of inflammatory cytokines and lipids under basal conditions and following chemical or physical damage. The two models evaluated are Skin2 (Advanced Tissue Sciences) and EpiDerm (Mattek Corporation). Model tissues were topically treated with SDS or were slice-wounded […]

CYTOKINE RESPONSE OF THE EPIDERM SKIN MODEL TO TOPICALLY APPLIED IRRITANTS AND TOXICANTS.

EpiDerm™, Mattek Corporation’s in vitro reproduction of the human epidermis provides a convenient way in which toxicity and irritation potential of chemicals and physical stresses can be assessed. Derived from single strains of human keratinocytes, the model contains layers of cells which have differentiated into easily recognizable component strata of human epidermis. These include basal, […]

IN VITRO PERMEATION AND IRRITATION OF BENZOYL PEROXIDE – CONTAINING PRODUCTS.

Two in vitro models to measure release of benzoyl peroxide (BPO) from formulations were presented. Franz-type diffusion cells and acetonitrile/water receptor mediums were used in both models. The barrier in one model was silicone sheeting and in the other was cultured human epidermis. The similarity in release profiles, rates of permeation, and diffusion coefficients obtained […]