1
|
Ponmozhi J, Dhinakaran S, Varga-Medveczky Z, Fónagy K, Bors LA, Iván K, Erdő F. Development of Skin-On-A-Chip Platforms for Different Utilizations: Factors to Be Considered. MICROMACHINES 2021; 12:mi12030294. [PMID: 33802208 PMCID: PMC8001759 DOI: 10.3390/mi12030294] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 03/05/2021] [Accepted: 03/08/2021] [Indexed: 12/20/2022]
Abstract
There is increasing interest in miniaturized technologies in diagnostics, therapeutic testing, and biomedicinal fundamental research. The same is true for the dermal studies in topical drug development, dermatological disease pathology testing, and cosmetic science. This review aims to collect the recent scientific literature and knowledge about the application of skin-on-a-chip technology in drug diffusion studies, in pharmacological and toxicological experiments, in wound healing, and in fields of cosmetic science (ageing or repair). The basic mathematical models are also presented in the article to predict physical phenomena, such as fluid movement, drug diffusion, and heat transfer taking place across the dermal layers in the chip using Computational Fluid Dynamics techniques. Soon, it can be envisioned that animal studies might be at least in part replaced with skin-on-a-chip technology leading to more reliable results close to study on humans. The new technology is a cost-effective alternative to traditional methods used in research institutes, university labs, and industry. With this article, the authors would like to call attention to a new investigational family of platforms to refresh the researchers’ theranostics and preclinical, experimental toolbox.
Collapse
Affiliation(s)
- J. Ponmozhi
- Microfluidics Laboratory, Department of Mechanical Engineering, IPS Academy-Institute of Engineering Science, Indore 452012, India;
| | - S. Dhinakaran
- The Centre for Fluid Dynamics, Department of Mechanical Engineering, Indian Institute of Technology Indore, Indore 453552, India;
| | - Zsófia Varga-Medveczky
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Práter u. 50a., 1083 Budapest, Hungary; (Z.V.-M.); (K.F.); (L.A.B.); (K.I.)
| | - Katalin Fónagy
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Práter u. 50a., 1083 Budapest, Hungary; (Z.V.-M.); (K.F.); (L.A.B.); (K.I.)
| | - Luca Anna Bors
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Práter u. 50a., 1083 Budapest, Hungary; (Z.V.-M.); (K.F.); (L.A.B.); (K.I.)
- Heart and Vascular Centre, Faculty of Medicine, Semmelweis University, 1122 Budapest, Hungary
| | - Kristóf Iván
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Práter u. 50a., 1083 Budapest, Hungary; (Z.V.-M.); (K.F.); (L.A.B.); (K.I.)
| | - Franciska Erdő
- Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Práter u. 50a., 1083 Budapest, Hungary; (Z.V.-M.); (K.F.); (L.A.B.); (K.I.)
- Correspondence:
| |
Collapse
|
2
|
Jacobs JJ, Lehé C, Cammans KD, Das PK, Elliott GR. Methyl Green-Pyronine Staining of Porcine Organotypic Skin Explant Cultures: An Alternative Model for Screening for Skin Irritants. Altern Lab Anim 2019; 28:279-92. [DOI: 10.1177/026119290002800206] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We describe a new alternative method for screening for skin irritants by using fresh intact porcine skin biopsies. Test chemicals were applied to the epidermis of the biopsies, which were then incubated for different times in tissue culture medium at 37°C and with 5% carbon dioxide. A decrease in epidermal keratinocyte RNA staining, visualised in frozen sections by using a modified methyl-green pyronine (MGP) staining procedure, was employed as a marker of irritancy. If a decrease in epidermal RNA was observed after incubation for 4 hours (strong irritant), the chemical had an MGP score of 3; if after incubation for 24 hours (moderate irritant), the MGP score was 2; and if after incubation for 48 hours (weak irritant), the MGP score was 1. If no keratinocyte cytotoxicity was observed after incubation for 48 hours, the chemical was classified as non-irritant (MGP score = 0). At least three ears were used per chemical. The average MGP score was used to classify the chemical. Based on the MGP score for 20% sodium dodecyl sulphate, chemicals classified as strong or moderate irritants by using the MGP test were grouped together as category R38 chemicals. Weak irritants or non-irritants were not classified (NC). The MGP staining correctly identified 23 of 25 skin irritants for which reference data were available.
Collapse
Affiliation(s)
- John J.L. Jacobs
- Department of Pharmacology, TNO-PML, P.O. Box 45, Rijswijk 2280 AA, The Netherlands
- Department of Dermato-immunopathology, UvA-AMC, The Netherlands
| | - Cynthia Lehé
- Department of Dermato-immunopathology, UvA-AMC, The Netherlands
| | - Keith D.A. Cammans
- Department of Pharmacology, TNO-PML, P.O. Box 45, Rijswijk 2280 AA, The Netherlands
| | - Pranab K. Das
- Department of Dermato-immunopathology, UvA-AMC, The Netherlands
| | - Graham R. Elliott
- Department of Pharmacology, TNO-PML, P.O. Box 45, Rijswijk 2280 AA, The Netherlands
| |
Collapse
|
3
|
Setti C, Suarato G, Perotto G, Athanassiou A, Bayer IS. Investigation of in vitro hydrophilic and hydrophobic dual drug release from polymeric films produced by sodium alginate-MaterBi® drying emulsions. Eur J Pharm Biopharm 2018; 130:71-82. [PMID: 29928979 DOI: 10.1016/j.ejpb.2018.06.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 06/15/2018] [Accepted: 06/17/2018] [Indexed: 02/02/2023]
Abstract
Emulsions are known to be effective carriers of hydrophobic drugs, and particularly injectable emulsions have been successfully implemented for in vivo controlled drug release. Recently, high internal phase emulsions have also been used to produce porous polymeric templates for pharmaceutical applications. However, emulsions containing dissolved biopolymers both in the oil and water phases are very scarce. In this study, we demonstrate such an emulsion, in which the oil phase contains a hydrophobic biodegradable polymer, MaterBi®, and the water phase is aqueous sodium alginate dispersion. The two phases were emulsified simply by ultrasonic processing without any surfactants. The emulsions were stable for several days and were dried into composite solid films with varying MaterBi®/alginate fractions. The films were loaded with two model drugs, a hydrophilic eosin-based cutaneous antiseptic and the hydrophobic curcumin. Drug release capacity of the films was investigated in detail, and controlled release of each model drug was achieved either by tuning the polymer fraction in the films during emulsification or by crosslinking sodium alginate fraction of the films by calcium salt solution immersion. The emulsions can be formulated to carry either a single model drug or both drugs depending on the desired application. Films demonstrate excellent cell biocompatibility against human dermal fibroblast, adult cells.
Collapse
Affiliation(s)
- Chiara Setti
- Smart Materials, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; Dipartimento di Informatica Bioingegneria, Robotica e Ingegneria dei Sistemi (DIBRIS), Universita Degli Studi di Genova, Via All'Opera Pia 13, 16145 Genova, Italy
| | - Giulia Suarato
- Smart Materials, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy; Drug Discovery and Development, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Giovanni Perotto
- Smart Materials, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | | | - Ilker S Bayer
- Smart Materials, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy.
| |
Collapse
|
4
|
Frade MAC, Andrade TAMD, Aguiar AFCL, Guedes FA, Leite MN, Passos WR, Coelho EB, Das PK. Prolonged viability of human organotypic skin explant in culture method (hOSEC). An Bras Dermatol 2015; 90:347-50. [PMID: 26131864 PMCID: PMC4516099 DOI: 10.1590/abd1806-4841.20153645] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 07/31/2014] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND: Currently, the cosmetic industry is overwhelmed in keeping up with the safety
assessment of the increasing number of new products entering the market. To meet
such demand, research centers have explored alternative methods to animal testing
and also the large number of volunteers necessary for preclinical and clinical
tests. OBJECTIVES: This work describes the human skin ex-vivo model (hOSEC: Human Organotypic Skin
Explant Culture) as an alternative to test the effectiveness of cosmetics and
demonstrate its viability through cutaneous keratinocytes' proliferative capacity
up to 75 days in culture. METHODS: The skin explants obtained from surgeries were cultured in CO2-humid
incubator. After 1, 7, 30 and 75 days in culture, skin fragments were harvested
for analysis with histomorphological exam (HE staining) on all days of follow-up
and immunohistochemistry for Ck5/6, Ck10 and Ki-67 only on the 75th day. RESULTS: On the 7th day, the epidermis was perfect in the dermoepidermal junction, showing
the viability of the model. On the 30th day, the epidermis was thicker, with fewer
layers on the stratum corneum, although the cutaneous structure was unaltered. On
the 75th day, the skin became thinner but the dermoepidermal junctions were
preserved and epidermal proliferation was maintained. After the 75th day on
culture, the skin was similar to normal skin, expressing keratinocytes with Ck5/6
on supra-basal layers; Ck10 on differentiated layers; and viability could be
assessed by the positivity of basal cells by Ki-67. CONCLUSION: The hOSEC model seems a good alternative to animal testing; it can be used as a
preclinical test analogous to clinical human skin test with similar effectiveness
and viability proven by immunohistological analyses.
Collapse
Affiliation(s)
| | | | | | - Flávia Araújo Guedes
- Private Institute of Clinical Research and Biotechnology, Ribeirao Preto, SP, Brazil
| | | | | | | | | |
Collapse
|
5
|
|
6
|
Chen H, Li S, Meng T, Zhang L, Dai T, Xiang Q, Su Z, Zhang Q, Huang Y. HSP27 as a biomarker for predicting skin irritation in human skin and reconstructed organotypic skin model. Toxicol Lett 2014; 226:124-31. [PMID: 24503015 DOI: 10.1016/j.toxlet.2014.01.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 01/18/2014] [Accepted: 01/27/2014] [Indexed: 11/19/2022]
Abstract
In vitro alternative tests aiming at replacing the traditional animal test for predicting the irritant potential of chemicals have been developed, but the assessing parameters or endpoints are still not sufficient. To discover novel endpoints for skin irritation responses, 2DE-based proteomics was used to analyze the protein expression in human skin exposed to sodium lauryl sulfate (SLS) following the test protocol of the European Centre for the Validation of Alternative Methods (ECVAM) in the present study. HSP27 was up-regulated most significantly among the eight identified proteins, consistent with our previous reports. Acid and basic chemicals were applied on human skin for further validation and results showed that the up-regulated expression of HSP27 was induced in 24h after the exposure. Skin-equivalent constructed with fibroblasts, basement membrane and keratinocytes was used to investigate the potential of HSP27 as a biomarker or additional endpoint for the hazard assessment of skin irritation. Our skin-equivalent (Reconstructed Organotypic Skin Model, ROSM) had excellent epidermal differentiation and was suitable for the skin irritation test. HSP27 also displayed an up-regulated expression in the ROSM in 24h after the irritants exposure for 15min. All these results suggest that HSP27 may represent a potential marker or additional endpoint for the hazard assessment of skin irritation caused by chemical products.
Collapse
Affiliation(s)
- Hongxia Chen
- Institute of Biomedicine and National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou 510632, China
| | - Shuhua Li
- Guangzhou Women and Children's Medical Center, Guangzhou 510623, China
| | - Tian Meng
- Institute of Biomedicine and National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou 510632, China
| | - Lei Zhang
- Institute of Biomedicine and National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou 510632, China
| | - Taoli Dai
- Institute of Biomedicine and National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou 510632, China
| | - Qi Xiang
- Institute of Biomedicine and National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou 510632, China; Guangdong Provincial Key Laboratory of Bioengineering Medicine, Jinan University, Guangzhou 510632, China
| | - Zhijian Su
- Institute of Biomedicine and National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou 510632, China; Guangdong Provincial Key Laboratory of Bioengineering Medicine, Jinan University, Guangzhou 510632, China
| | - Qihao Zhang
- Institute of Biomedicine and National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou 510632, China; Guangdong Provincial Key Laboratory of Bioengineering Medicine, Jinan University, Guangzhou 510632, China.
| | - Yadong Huang
- Institute of Biomedicine and National Engineering Research Center of Genetic Medicine, Jinan University, Guangzhou 510632, China; Guangdong Provincial Key Laboratory of Bioengineering Medicine, Jinan University, Guangzhou 510632, China.
| |
Collapse
|
7
|
Abstract
The evaluation of eye and skin irritation potential is essential to ensuring the safety of individuals in contact with a wide variety of substances designed for industrial, pharmaceutical or cosmetic use. The Draize rabbit eye and skin irritancy tests have been used for 60 years to attempt to predict the human ocular and dermal irritation of such products. The Draize test has been the standard for ocular and dermal safety assessments for decades. However, several aspects of the test have been criticised. These include: the subjectivity of the method; the overestimation of human responses; and the method's cruelty. The inadequacies of the Draize test have led to several laboratories over the last 20 years making efforts to develop in vitro assays to replace it. Protocols that use different types of cell cultures and other methods have been devised to study eye and skin irritation. Different commercial kits have also been developed to study eye and skin irritation, based on the action of chemicals on these tissues. This article presents a review of the main alternatives developed to replace the use of animals in the study of chemical irritation. Particular attention is paid to the reproducibility of each method.
Collapse
Affiliation(s)
- M P Vinardell
- Department of Fisiologia, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain.
| | | |
Collapse
|
8
|
Welss T, Basketter DA, Schröder KR. In vitro skin irritation: facts and future. State of the art review of mechanisms and models. Toxicol In Vitro 2005; 18:231-43. [PMID: 15046769 DOI: 10.1016/j.tiv.2003.09.009] [Citation(s) in RCA: 177] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2003] [Accepted: 09/19/2003] [Indexed: 11/27/2022]
Abstract
The skin is the main target tissue for exogenous noxes, protecting us from harmful environmental hazards, UV-irradiation and endogenous water loss. It is composed of three layers, whereas the outermost epidermis is a squamous epithelium that mainly consists of keratinocytes. These cells execute a terminal differentiation, which finally results in the assembly of the stratum corneum. This layer, consisting of cornified keratinocytes, is an effective barrier against a vast number of substances. Apart of this, keratinocytes play crucial roles in the immune surveillance and the initiation, modulation and regulation of inflammation in the epidermis. Regarding cutaneous inflammatory reactions, skin irritation is one of the most common adverse effect in humans. For reasons of human safety assessment new chemicals are still evaluated for irritant potentials by application to animals followed by visible changes such as erythema and oedema. Testing for skin irritation in animals potentially cause them pain and discomfort. Furthermore, the results are not always predictive for those found in humans. In order to replace animal testing and to improve the prediction of irritants, the cosmetic and toiletry industry, in Europe represented by Colipa, develops and uses several alternative in vitro test systems. In this respect, the use of in vitro reconstructed organotypic skin equivalents are mostly favored, because of their increasingly close resemblance to human skin. Due to ethical and scientific questions and on account of the 7th amendment of the European Council Directive 76/768/EEC, the authors see the requirement to drive the development of alternative tests for irritants. Therefore, this article centres on cosmetic ingredients and provides the readership an overview of the state of art of cellular mechanisms of skin irritation and summarizes the results of the commonly used skin equivalents to evaluate irritation in vitro.
Collapse
Affiliation(s)
- Thomas Welss
- VTB-Skin Biochemistry, Henkel KGaA, Building Z33, Henkelstrasse 67, D-40191, Duesseldorf, Germany.
| | | | | |
Collapse
|
9
|
Jacobs JJL, Lehé C, Cammans KDA, Das PK, Elliott GR. An in vitro model for detecting skin irritants: methyl green-pyronine staining of human skin explant cultures. Toxicol In Vitro 2002; 16:581-8. [PMID: 12206825 DOI: 10.1016/s0887-2333(02)00039-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We evaluated the potential of human organotypic skin explant cultures (hOSECs) for screening skin irritants. Test chemicals were applied to the epidermis of the skin explants which were incubated for 4, 24 or 48 h in tissue culture medium. A decrease in epidermal RNA staining, visualised in frozen sections using a modified methyl-green pyronine (MGP) staining procedure, was used as a marker of irritancy. A decrease in epidermal RNA after a 4-, 24- or 48-h exposure to a certain concentration of a test chemical equated to a MGP score of 3, 2 or 1, respectively. The MGP score was 0 if there was no keratinocyte cytotoxicity after a 48-h exposure. A minimum of three donors were used per chemical and the average MGP score was used to classify the chemical as irritant or not. Chemicals with an average MGP score > or =1.5 were classified as irritants (R38), at that concentration. Chemicals with a MGP score <1.5 were not classified (NC), at that concentration. The results obtained using human skin in vitro were compared with published data obtained using cultured porcine skin, the cutaneous Draize test (from this point referred to as the "rabbit skin irritation test") and volunteer studies. There was an excellent correlation between the classification of a chemical, as R38 or NC, based on hOSEC and results of volunteer studies. The hOSEC model predicted perfectly the irritation hazard of the 22 chemicals for which volunteer data were available. The porcine OSEC correctly predicted the classification of 21 of 22 (95%) chemicals and the rabbit skin irritation test correctly predicted the classification of 14 of 15 chemicals (93%) for which data were available. In conclusion, MGP staining of human skin explant cultures can be used to predicted human skin irritancy in vivo. In addition, the data validate the use of porcine skin as an alternative to human skin for screening for dermal irritants in vitro.
Collapse
Affiliation(s)
- J J L Jacobs
- Department of Pharmacology, TNO-PML, Rijswijk, The Netherlands.
| | | | | | | | | |
Collapse
|
10
|
Faller C, Bracher M, Dami N, Roguet R. Predictive ability of reconstructed human epidermis equivalents for the assessment of skin irritation of cosmetics. Toxicol In Vitro 2002; 16:557-72. [PMID: 12206823 DOI: 10.1016/s0887-2333(02)00053-x] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The aim of this study 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, covering the full range of in vivo scores and representing different cosmetic product classes, were tested in vivo (modified Frosch-Kligman Soap Chamber Patch Test with repetitive occlusive application) and in vitro using two epidermis equivalents commercially available as kits (EpiDerm and EPISKIN) and one in-house model (Cosmital). In vivo, skin reactions (erythema, dryness and fissures) were visually evaluated and, in addition, skin redness and transepidermal water loss (TEWL) were measured by means of technical instruments. The parameters measured in vitro were the percent cell viability in the MTT reduction assay, with ET(50) determination, and the extracellular release of the pro-inflammatory mediator IL-1alpha and of the cytosolic enzyme lactate dehydrogenase (LDH), into the culture medium collected after topical application of the products for different exposure times (time-course assay). In general, good Spearman rank correlations could be observed between the different in vivo parameters (with the exception of TEWL and dryness at day 2). Furthermore, high correlation coefficients were obtained by comparing the different in vitro parameters (except for LDH release) and different models, which allowed to conclude that the results obtained with the different reconstructed epidermis models were very similar. A comparison between in vivo and in vitro parameters resulted in the best rank correlation for ET(50), then in decreasing order, for the percent MTT viability at 16 h, the IL-1alpha release and finally, for LDH release, where the correlation was generally low. A direct comparison of the mean total scores (sum of erythema, dryness and fissures at day 5) of the 22 products with the best predictor, ET(50) obtained with the three reconstructed epidermis models, using simple linear regression analysis resulted in a coefficient of correlation R=0.94 for EpiDerm, R=0.90 for Cosmital and R=0.84 for EPISKIN. Multivariate descriptive statistics showed that the in vitro parameters, MTT viability evaluated after the 16-h exposure and ET(50), as well as the in vivo parameters, sum of visual scores at day 5 and chromameter value, were the best endpoints to discriminate between irritant and non-irritant products. Using the in vivo mean total scores at day 5 with a cut-off value at 2 and the in vitro percent MTT viability after the 16-h exposure with a cut-off value at 50% to classify the products, the same two-by-two contingency table was obtained for all the three reconstructed epidermis models with sensitivity=92%, specificity=100% and observed concordance=95% (kappa=0.91; 95% confidence interval 0.74-1.08). This classification system was a satisfactory and relevant approach to discriminate the "irritant" from the "non-irritant" cosmetic products in this study. In conclusion, this study demonstrated the usefulness of reconstructed human epidermis equivalents for the in vitro assessment of the irritation potential of a series of cosmetic products. These models allow the measurement of quantifiable and objective endpoints relevant to in vivo irritative phenomena.
Collapse
Affiliation(s)
- C Faller
- Cosmital SA (Research Company of Wella AG, Germany), Rte de Chésalles 21, CH-1723 Marly, Switzerland.
| | | | | | | |
Collapse
|
11
|
Eun HC, Suh DH. Comprehensive outlook of in vitro tests for assessing skin irritancy as alternatives to Draize tests. J Dermatol Sci 2000; 24:77-91. [PMID: 11064242 DOI: 10.1016/s0923-1811(00)00093-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In vitro alternative methods have been verified for the possibility to assess cutaneous irritancy because humans cannot be direct initial experimental subjects and animal experimentation could be forbidden in the near future. Many kinds of cell cytotoxicity assays have been tried, revealing their own advantages and limitations. Cell function-based tests have been used less frequently than cytotoxicity assays. Three-dimensional culture systems are promising because they are closer to the actual in vivo skin, and some of them are commercialized nowadays. The ultimate objective of in vitro irritancy tests, which is the high degree of correlation with human in vivo test results, has been accomplished in many experimental settings. Before applying these in vitro methods we must consider several points, including cell sources, irritant characteristics, exposure time, endpoint of experiment, extrinsic factors affecting irritation, etc. In vitro skin irritancy tests have been developed continuously, and in the future they could assume a heavy responsibility of estimating the irritancy in human skin in vivo.
Collapse
Affiliation(s)
- H C Eun
- Department of Dermatology, Seoul National University Hospital, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, 110-744, Seoul, South Korea.
| | | |
Collapse
|
12
|
The Influence of the Response of Skin Equivalent Systems to Topically Applied Consumer Products by Epithelial--Mesenchymal Interactions. Toxicol In Vitro 1999; 13:219-29. [DOI: 10.1016/s0887-2333(98)00087-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/16/1998] [Indexed: 12/29/2022]
|
13
|
Benassi L, Bertazzoni G, Seidenari S. In vitro testing of tensides employing monolayer cultures: a comparison with results of patch tests on human volunteers. Contact Dermatitis 1999; 40:38-44. [PMID: 9928803 DOI: 10.1111/j.1600-0536.1999.tb05974.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Evaluation of the irritant potential of new products or ingredients prior to human testing is generally performed in vivo on animals. However, according to the 6th amendment and following updates of the European Community directive on cosmetic products (93/35/EEC), animal testing will be banned when suitable substitutes will be available. To know whether in vitro tests for assessment of skin irritancy provide results approaching human conditions, comparisons have to be made between data deriving from in vitro tests and skin response in humans. The aim of our study was to assess the validity of the monolayer culture system of normal human keratinocytes as a model for the evaluation of the irritant effects of detergents, by comparing in vitro cell culture data to in vivo acute skin irritancy effects of cocamidopropyl betaine (CAPB), an amphoteric compound, Tween 20 (TW20) (polysorbate 20) and Tween 80 (TW80) (polysorbate 80), representing nonionic compounds, applied to the skin of 24 healthy volunteers at a concentration similar to that employed in commercial products. As parameters for cytotoxicity, cell proliferation, cell membrane integrity and cell metabolism were assessed by cell counts, thymidine incorporation, MTT conversion, and Neutral Red uptake. In order to increase the sensitivity of the in vivo evaluation, bioengineering methods for assessment of the effects of test products on the skin were employed. Whereas all 4 in vitro methods ranked the tensides according to their toxicity in the following order: CAPB>SLS>TW20>TW80, both in vivo methods agreed in identifying SLS as the most irritating substance. Moreover, as compared with the irritation potential on human skin, all 4 in vitro tests overestimated the toxicity of CAPB. This suggests that the keratinocyte monolayer cell culture technique cannot directly replace in vivo methods, and that data obtained by this method should be interpreted cautiously.
Collapse
Affiliation(s)
- L Benassi
- Department of Dermatology, University of Modena, Italy
| | | | | |
Collapse
|