Reconstructed Tissues

Our reconstructed skin models have been optimized to analyze the impact of chemicals, active ingredients and products on tissue architecture and physiological properties like cell growth, skin metabolism, the synthesis of collagen, elastin and other extracellular matrix proteins and many more.

  • Phenion FT
  • Phenion FT LONG-LIFE
  • Phenion FT AGED
  • Phenion OS-REp
  • NEW epiCS
  • NEW epiCS-M

The Phenion FT Skin model is ideally suited to study the interactions between epidermis and dermis. Based on our special culture conditions, the skin model differentiates and stratifies similar to native human skin, which includes the generation of a horny layer. Analyses can be conducted with the whole tissue as well as with both compartments, dermis and epidermis, separately. A protocol for the enzymatic separation of the tissues can be found in our download center, together with protocols for the extraction and analysis of DNA, RNA and proteins from the skin tissue.

Order Details:

The Phenion® Full-Thickness (FT) Skin Model can be ordered in 3 different versions, the FT Standard version, the FT INSERT version, and the FT LARGE version. 

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Phenion FT Skin Model

Phenion FT Skin Model

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Visualization of exemplary differentiation proteins by immunofluorescent labeling.

Visualization of exemplary differentiation proteins by immunofluorescent labeling.

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Immunohistology shows well organized epidermal differentiation.

Immunohistology shows well organized epidermal differentiation.

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Ki67 antibody localizes proliferating basal keratinocytes in the epidermis.

Ki67 antibody localizes proliferating basal keratinocytes in the epidermis.

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Cytokeratin 10/15 immunostaining of matured Phenion FT Skin Model.

Cytokeratin 10/15 immunostaining of matured Phenion FT Skin Model.

Open Slideshow Microscopic view optical coherence tomography

Optical coherence tomography (OCT) is used as non-invasive tool allowing fine-meshed batch control. 

The FT standard version:

The Phenion® FT Skin Model is characterized by a diameter of 1.4 cm, which results in a tissue surface area of 1.5 cm2.

The Phenion FT Skin Model can be purchased at any number (order number FT SM-1). Together with the Phenion FT Skin Models sufficient cell culture material, required for culturing the tissues in your lab (sterile petri dishes, filter papers, spacers) is provided. These consumables enable either individual tissue culture in separate vessels (small petri dishes) or the joint culture ‏of up to 6 models in a single medium-sized petri dish.

Tailor-made culture medium needs to be ordered separately. We recommend fresh medium for proper culture conditions every other day, the respective medium volume should be calculated with 5 ml per tissue. You will find more details in the Instructions for Use.

The FT INSERT version:

The Phenion® FT INSERT Skin Model has the same size as the FT standard skin model (surface area 1.5 cm2, diameter 1.4 cm), but is produced in co-culture inserts on a polyethylene membrane. Tissue architecture and physiological properties are identical to the standard version.

The defined insert compartment above the tissue surface allows e.g. the inoculation with microorganisms without contaminating the rest of the culture system, as well as the treatment with larger volumes of test items. This format also paves the way for the automation of tests, as the tissues in inserts can be precisely handled by robotic elements.

The specially designed inserts allow the culture of the tissues either in a hanging position, preferably in 6-well or 12-well plates, or, due to small sockets underneath the insert, in an upright standing position in culture vessels of any format. With this flexibility in use the fields of application for the Phenion® FT Skin Model are further expanded.

The FT INSERT models (order number FT INSERT-1) can be purchased at any number. Sufficient cell culture material (sterile 6-well plates) required for culturing the tissues in your lab is provided with each shipment.

Tailor-made culture medium needs to be ordered separately. We recommend fresh medium for proper culture conditions every other day, the respective medium volume should be calculated with 5 ml for hanging culture and 2 ml for standing inserts in a 6-well plate. Alternatively, the tissues can be maintained in a 12-well plate, too, which requires 2.2 ml culture medium in the hanging and 0.8 ml in the standing position. You will find more details in the Instructions for Use.

The FT LARGE version:

The Phenion® FT LARGE Skin Model features a tissue surface area of 7.7 cmwhich corresponds to a diameter of 3.1 cm. Tissue architecture and physiological properties are identical to the standard version.

The minimal order quantity comprises 2 FT LARGE models (order number FT LARGE-1). Higher skin model quantities can be purchased according to your individual needs. All Phenion FT LARGE Model shipments are equipped with sufficient cell culture material required for culturing the tissues in your lab (sterile petri dishes, filter papers, spacers). The material delivered with the LARGE models enables either individual tissue culture in separate vessels or the joint culture ‏of 2 models each.

Tailor-made culture medium needs to be ordered separately. We recommend fresh medium for proper culture conditions every other day, the respective medium volume should be calculated with 35 ml/large petri dish (∅ 100 mm).

Related products:

Air-Liquid interface culture medium (order number ALI-CM-250)

Please be aware that you also need to order a respective volume of Air-Liquid interface culture medium (order number ALI-CM-250) to take the FT models back into culture after arrival in your lab. The ALI medium has been designed to best support viability, tissue architecture and physiology of the Full-Thickness Skin models. As an indicator, a volume of 250 ml ALI medium is sufficient to culture 6 standard FT models in separate petri dishes for up to 10 days. 

We provide the Air-Liquid Interface culture medium in different compositions, e.g. without phenol red, hydrocortisone or antibiotics, thus meeting your individual experimental strategies.

The human Phenion Full-Thickness Skin Model mimics native human skin in diverse dimensions, such as in histological architecture and in a wide spectrum of physiological and biochemical parameters. Its biological equivalence with human skin makes the tissue perfectly suited as in vitro alternative to animal testings, e.g. in the 3D Skin Comet assay for genotoxicity testing and in a vast variety of research applications as listed below. 

Fields of application: 

  • Basic research in skin physiology and biochemistry
  • Clinical dermatological research
  • Claim substantiation for cosmetic ingredients
  • Transdermal drug delivery studies
  • Skin penetration studies
  • Mode of action of pharmaceuticals and actives
  • Wound healing studies
  • Toxicological assessment of chemicals and products
  • Analysis of environmental effects on skin physiology, e.g. UV and IR irradiation
Phenion_FT_Long-Life_skin_model_morphology_during_culture

Phenion FT LL, tissue morphology (H&E stain, paraffin sections)

With the Phenion FT LONG-LIFE model we are offering a full-thickness skin equivalent which can be kept in culture for up to 50 days after arrival at your lab. Based on innovative protocols, fibroblasts and keratinocytes have achieved an advanced state of homeostasis at a very early stage during tissue production, which is maintained throughout the whole culture period. The 4 times extended life-span, compared to the standard FT model, opens the gateway to completely new application fields.

It allows to monitor physiological, biochemical and genetic processes, e.g. after tissue exposure with chemicals, formulations or environmental impacts, over a long period of time. Late-onset or long-term effects can be studied as well as recovery or regeneration after tissue treatment. The LONG-LIFE model is also ideally suited for repeated dosing, and it could provide an in vitro platform for research into development and treatment of skin tumors.

The standardized LONG-LIFE production processes guarantee the same high level of quality offered by the other Phenion skin models. 

The Phenion FT LONG-LIFE model can be purchased at any number (order number FT LONG-LIFE-1) at a price of 228 $ per piece. Together with the Phenion FT LONG-LIFE Skin Models we provide sterile petri dishes, filter papers, spacers which are required for culturing the tissues in your lab. This material enables either individual tissue culture in separate vessels (small petri dishes) or the joint culture ‏of up to 6 models in a single medium-sized petri dish.

Tailor-made culture medium needs to be ordered separately. We recommend fresh medium for proper culture conditions every other day, the respective medium volume should be calculated with 5 ml per tissue. You will find more details in the Instructions for Use provided on our website phenion.com. 

Characteristics

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Integrin alpha 3 is located on the surface of the basal keratinocytes and acts as a major component of the cell adhesion complex

Integrin alpha 3 is located on the surface of the basal keratinocytes and acts as a major component of the cell adhesion complex

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Cytokeratin 15 is expressed as stem cell marker in the basal keratinocytes

Cytokeratin 15 is expressed as stem cell marker in the basal keratinocytes

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 Cytokeratin 10 is located in all supra-basal living layers of the epidermis

Cytokeratin 10 is located in all supra-basal living layers of the epidermis

  • Tissue dimensions: 1.4 cm in diameter, 3 mm thickness
  • Constructed on basis of proprietary collagen matrix
  • Human skin fibroblasts and keratinocytes from single donor origin
  • Extended experimental phase of at least 50 days

The Phenion FT AGED Skin Model is a surrogate for aged human skin. It mimics mature human skin, both in structure and physiology. The Phenion FT AGED Skin Model is characterized by a connective tissue with senescent fibroblasts, reduced synthesis of extracellular matrix (ECM) proteins like collagen and elastin, and elevated MMP secretion (Scholz, 2014, Master thesis; Dieckmann et al., 2016). With these features, the Phenion FT AGED Skin Model is an ideal research tool to study the basic biology of skin ageing mechanisms and to develop formulations which can delay or even counteract ageing.

In the Phenion FT AGED Skin Model the dermal fibroblasts are treated with mitomycin C (MMC) for 48 hours before adding the keratinocytes. The cytostatic drug MMC is an alkylating agent, which, after becoming activated within the cells, leads to covalent crosslinking of the DNA strands (Lee et al., 2006). Crosslinked DNA sections cannot be further transcribed or replicated, and cell proliferation stops. In addition, activated MMC generates reactive oxygen species (ROS), which can damage the DNA, too (Alili et al., 2014). Both effects, cell cycle arrest and ROS generation, are characteristic for the extrinsic and intrinsic ageing of the human skin. It could be demonstrated that human dermal fibroblasts can be arrested in the cell cycle and driven into senescence when they are treated with MMC in culture.

Features

Phenion® AGED Skin Model

Reduced proliferation of Fibroblasts (BrdU-Assay)

Increased ROS (2’,7’-Dichlorfluorescein-Assay)

Increased MMP-1 activity (ELISA-Assay)

Reduced gene expression for Collagen type-1 and -3 (RT-PCR)

Reduced collagen synthesis (Procollagen Type 1 C-peptide ELISA)

Reduced gene expression for Elastin (RT-PCR)

Reduced synthesis of Elastin, Filaggrin, Loricrin, Involucrin (Immunohistochemistry)

The table exemplifies some skin ageing features of the Phenion® AGED Skin Model in comparison to our standard full thickness skin model.


Order details:

Phenion FT skin model compared to Phenion Aged FT skin model

Phenion FT AGED Skin Model

The minimal order quantity comprises 6 FT AGED skin models (Phenion FT AGED Skin Model Kit, order number FT AGED-6) and can be purchased at a price of 1080 $/kit.

Please note: kits with higher skin model quantities can be purchased at a price of 180 $ per additional tissue, according to your individual needs. The Phenion FT AGED Skin Model Kits are equipped with sufficient materials required for the culture of the tissues. The materials delivered with the kits enable individual tissue culture in six separate vessels or the joint cultivation ‏(e.g. 2 x 3 or 1 x 6) of the skin models.

Content of the Phenion FT AGED Skin Model kit*
6Full Thickness Skin Models (placed on transport-agar in a 24-well plate)
6Sterile filter spacers
6Sterile small petri dishes (35/10 mm)
2Sterile large petri dishes (100/20 mm)
6Sterile pieces of filter paper (approx. 20 x 20 mm)
1Sterile piece of filter paper (approx. 55 x 65 mm)

*Please order 250 ml ALI-Medium (ready-to-use) separately to culture six Skin Models.

Preview image of skin model instructions pdf for download.

Phenion FT Skin Model Kit Instructions for Use

For further instructions, please take note of the Phenion FT Skin Model Kit Instructions for Use, available here. 

The Open Source Reconstructed Epidermis [OS-REp] is a cost-effective alternative for applications which do not rely on OECD-approved tissues and methods or which do not need complex skin equivalents.

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Culture of several Phenion OS-REp models in a petri dish

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Culture of a Phenion OS-REp model in a 6-well plate

Culture of a Phenion OS-REp model in a 6-well plate

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Easy handling of the Phenion OS-REp model

Easy handling of the Phenion OS-REp model

The OS-REp consists of carefully selected primary human keratinocytes cultured under air-liquid interface conditions. All epidermal layers characteristic for native human skin are developed including a multi-layered stratum corneum. Its high xenobiotic metabolic competence is comparable to that expressed in the epidermis of the Phenion® Full-Thickness Skin Model and in human skin (Wiegand et al., 2014).

OS-REp tissues are grown in inserts on a chemically resistant polycarbonate membrane (effective tissue surface area 0.63 cm2). Due to small spacers (“feet”) underneath the tissue-containing inserts, they can be placed in diverse cell culture vessels of different sizes to e.g. allow for co-culturingThus, the OS-REp can be handled very flexible to cope with many different experimental set-ups.

The medium volume in the chosen cell culture vessel must be thoroughly adjusted to guarantee air-liquid interface conditions and nutrient supply over a certain period of time. Table 1 lists the required media volumes to culture different numbers of OS-REp models in different culture vessels. Medium must be changed every 48-72 hours.

culture vessel

# OS-REp models

medium volume

6-well plate

1 tissue

1.5 ml

Petri dish, Ø 10 cm

up to 4 tissues

9 ml

Petri dish, Ø 14.5 cm

up to 10 tissues

23 ml

Performance:

Based on the OS-REp, an in vitro skin irritation test was developed which follows the conditions defined in the OECD test guideline 439. The test method has been validated in a multicentric study with several international partners according to the OECD Performance Standards for in vitro skin irritation tests. The test results, which have proven its good predictive capacity, as well as the technology behind the OS-REp models have been published (Mewes et al., 2016; Groeber et al., 2016).

A detailed SOP for running the in vitro skin irritation test can be downloaded from the Information Center of the Phenion homepage.

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Open Slideshow Histological section of Phenion OS-REp epidermal model

Histological section through the Phenion OS-REp model; H&E staining

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Cytokeratin 10 expression in the suprabasal kerationcytes; immunostaining

Cytokeratin 10 expression in the suprabasal kerationcytes; immunostaining

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Laminin-5 expression at the membrane-tissue interface; immunostaining

Laminin-5 expression at the membrane-tissue interface; immunostaining

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Ki-67 expression in proliferating basal keratinocytes; immunostaining

Ki-67 expression in proliferating basal keratinocytes; immunostaining

Order Details:

OS-REp models can be ordered at any number needed at a price of 45 €/tissue (product ID: OS-REp-1). The models can be cultured under air-liquid interface conditions either individually in the wells of a 6-well plate or in groups, e.g. in medium-sized (Ø 10 cm) or big (Ø 14.5 cm) petri dishes. The respective number of sterile 6-well plates and petri dishes, adapted to the number of requested tissues, are included in the shipment.

Please note: According to individual experimental needs, Phenion Air-Liquid Interface (ALI) medium shall be ordered separately and is available at 3 different sizes: 125 ml, 250 ml, and 500 ml (product ID: OS-REp ALI-CM-125/250/500). Instructions of Use can be downloaded from the “Information Center” of the Phenion homepage.

What is a human epidermal skin model?

Reconstructed human Epidermis (RhE) models are three dimensional human epidermis equivalents which can be used as in vitro methods for different applications. They are derived from normal human keratinocytes and form a multilayered, highly differentiated model of the human epidermis that mimics biochemical and physiological properties of the epidermis. During cultivation the tissue cultures are lifted to the air-liquid interphase to induce differentiation, epithelial stratification and cornification. The cellular structure of RhE closely resembles the human epidermis including a basement membrane, proliferating keratinocytes and a stratum corneum with intact barrier function.
Due to the skin barrier function of the epidermis, liquid, creamy and solid substances can be applied topically -onto the stratum corneum - to closely mimic the in vivo situation. Substances can also be applied systemically by adding to the cell culture medium.

How can the epidermal skin model be characterised?

The morphology and architecture of epiCS shows a high comparability to human native epidermis. It comprises of a stratified squamous epithelium. Proliferating cells of the basal layer undergo a series of morphological and biochemical changes that culminate in the production of dead, flattened, enucleated squames. Several markers of differentiation prove the functionality of the reconstructed epidermis:


H&E staining

H&E staining reveals well organized epidermal differentiation of epiCS

Cytokeratin 10

Cytokeratin 10 immunostaining of the suprabasal keratinocytes

Filaggrin

Filaggrin immunostaining reveals terminal epidermal differentiation

epiCS for in vitro skin corrosion testing

The epiCS is an OECD-approved epidermal model to conduct an in vitro skin corrosion assay according to OECD TG 431. Skin corrosion refers to the production of irreversible damage to the skin manifested as visible necrosis through the epidermis and into the dermis, following the application of a test chemical [as defined by the United Nations (UN) Globally Harmonized System of Classification and Labelling of Chemicals (GHS), cited in the OECD TG 431]. The validation study for the epiCS method for skin corrosion testing revealed very good results for the discrimination of corrosive from non-corrosive chemicals (100% sensitivity, 84.7% specificity, 92.4% accuracy). This test method can also be used for sub-categorisation of corrosives in GHS Cat. 1A and GHS Cat. 1B/C.
In the in vitro skin corrosion test the test items are topically applied onto the epiCS models for 3 and 60 minutes, respectively. After the exposure time, tissue viability is determined with the MTT assay. The prediction model to identify corrosive substances is defined in the OECD TG 431:
 

Prediction to be considered

Viability measured after exposure time points (t=3 and 60 minutes)

corrosive

< 50% after 3 minutes or

corrosive

≥ 50% after 3 minutes exposure AND

< 15% after 60 minutes exposure

Optional Sub-category 1B/C

≥ 15% after 3 minutes exposure

Optional Sub-category 1A

< 15% after 3 minutes exposure

Reference: OECD TG 431 - In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method (2019)

epiCS for in vitro skin irritation testing

The epiCS is an OECD-approved epidermal model to conduct an in vitro skin irritation assay according to OECD TG 439. Skin irritation refers to the production of reversible damage to the skin occurring after exposure to a substance or mixture [as defined by the United Nations (UN) Globally Harmonized System of Classification and Labelling of Chemicals (GHS), cited in the OECD TG 439]. The validation study for the epiCS method for skin corrosion testing revealed very good results for the discrimination of irritating from non-irritating chemicals (100% sensitivity, 80% specificity, 90% accuracy). It is documented in the ESAC opinion (ESAC Opinion Number 2016-5) and an independent peer review in 2018 (Peer Review Report of the Validation of the Skin Irritation Tests 2018).

In the in vitro skin irritation test the test items are topically applied onto the epiCS models for 20 minutes, followed by a post-incubation period of 42 hours. After this time, tissue viability is determined with the MTT assay. The prediction model to identify irritating substances is defined in the OECD TG 439:

Prediction to be considered

Viability measured after 20 minutes exposure + 42 hours post-incubation

irritating

≤ 50%

Non-irritating

> 50%

Reference: OECD TG 439- In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method (2020)

Download epiCS Manual

Here you can download our latest epiCS manual: 

What is a pigmented epidermal skin model?

A reconstructed human pigmented epidermal model e.g. epiCS-M consists of normal epidermal keratinocytes and melanocytes cultured at the air liquid interface (AL) and is characterised by a fully differentiated epidermis with underlying melanocytes. This highly differentiated model of the human epidermis shows epithelial stratification and cornification in the upper layers with an intact barrier function while the melanocytes and proliferating keratinocytes are located in the basal compartment. The location of melanin and melanocytes in the basal layers of the model can be visualized by Fontana-Masson or melanocyte-specific antibody (e.g., HMB45) staining (Fig. 1). Melanogenesis can be observed throughout the culture period. The degree of pigmentation in this model can be varied by using different melanocyte populations from e.g., Caucasian, Asian-Caucasian or Afro-American donors (Fig. 2).

Due to the skin barrier function of the epidermis, liquid, creamy and solid substances can be applied topically -onto the stratum corneum- to closely mimic the in vivo situation of cosmetics application. Some substances can also be applied systemically by adding to the cell culture medium. Both ways of application allow pigmentation studies. This model is an ideal tool for skin tanning or lightening studies as well as for melanogenesis research. To study the tanning potential of the model the melanin production can be stimulated with UV light, IBMX (3-Isobutyl-1-Methyl-Xanthine), or α-MSH (Melanin Stimulating Hormone). In contrast, lightening of matured or tanned tissue models is achieved e.g., with Kojic Acid (5-hydroxy-2-(hydroxymethyl)-4-pyrone), a known inhibitor of melanogenesis generally used for whitening in cosmetic products. The melanin content can be quantified by solvent extraction and determination of the optical density at 492 nm wavelength. Because epiCS-M can be cultured for a few weeks at airlift culture sufficient time is provided to study skin differentiation, pigmentation or de-pigmentation.

How can the pigmented epidermal skin model be characterised?

The reconstructed human pigmented epidermal model is characterised by a fully differentiated stratified epidermis where melanocytes are located in the basal cell layer. Melanin is synthesized by melanocytes and transferred to the neighbouring keratinocytes by their dendrites. This in vitro skin model can be used to investigate the tissue morphology for up to four weeks starting on day seven AL. HMB45 staining shows the location of melanocytes in the basal layers of the model during the airlift culture period. Melanin can be visualised with Fontana-Masson staining of the tissues.

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Fig. 1 This figure demonstrates H&E staining of epiCS-M and markers specific for cornification (filaggrin) and melanocytes (HMB45) at days 7 or 14 of AL.

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Fig. 2 Development of pigmentation of epiCS-M over time. Caucasian melanocyte donor display different stages of pigmentation during three weeks AL culture.


Download epiCS-M manual

Here you can download our latest epiCS-M manual: