Tissue Models
Leverage advanced in vitro human tissue models to achieve more predictive, ethical, and regulatory-compliant safety testing. These 3D reconstructed human tissue systems replicate key biological responses, providing reliable data for skin irritation, eye irritation, sensitization, and medical device biocompatibility assessments. Human-relevant models help reduce animal testing, support global regulatory acceptance (OECD, ISO, FDA, EPA, EU REACH), and accelerate product development across pharmaceuticals, cosmetics, chemicals, and medical devices.
For over 50 years, MB Research Labs has been a leader in toxicology testing, with deep expertise in applying human-derived 3D tissue models for safety and biocompatibility studies. Our team routinely performs OECD- and ISO-compliant in vitro assays for skin irritation, eye irritation, sensitization, and medical device evaluations. With decades of regulatory knowledge and hands-on experience, MB Research delivers reliable, human-relevant data that helps clients reduce animal use, meet global compliance standards, and bring products to market with confidence.
Quick Jump:
DERMAL MODELS
ISO 10993-23:2021 introduced a modern, human-relevant approach to evaluating the skin irritation potential of medical device extracts. Unlike older in vivo methods, this standard uses Reconstructed Human Epidermis (RhE) models to replicate the key biological processes of irritation in human skin. Test articles are extracted from the medical device under controlled conditions and then applied to the RhE tissue. Tissue viability is measured after exposure to determine whether the device or its components may cause irritation.
This in vitro assay provides scientifically robust and reproducible data while aligning with the global shift away from animal testing for medical devices.
At MB Research Labs, our experienced scientists routinely perform ISO 10993-23 irritation studies under GLP conditions, ensuring data that is regulatory-ready, accurate, and defensible. With decades of expertise in medical device biocompatibility testing, MB Research helps manufacturers meet ISO 10993 requirements efficiently—supporting greater confidence in product safety.
OECD Test Guideline 439 is the internationally recognized in vitro method for assessing skin irritation without the use of animals. This assay uses Reconstructed Human Epidermis (RhE) models, which closely mimic the structure and function of human skin, to evaluate whether a chemical, cosmetic, pharmaceutical, or medical device extract may cause reversible skin damage. Tissue viability is measured following exposure, providing a reliable indicator of irritation potential.
Results are directly linked to the EU and Globally Harmonized System (GHS) for Classification and Labelling of Chemicals:
- Irritating or Corrosive (GHS Category 2 or GHS Category 1) – if tissue viability is reduced below the specified threshold (50%).
- GHS No Category – if tissue viability remains above the threshold (50%), indicating the test article is not classified as a skin irritant.
OECD Test Guideline 431 provides a validated in vitro method for identifying skin corrosive substances using Reconstructed Human Epidermis (RhE) models. This assay measures cell viability following exposure to a test article to determine if it causes irreversible tissue damage—the hallmark of skin corrosion.
Results are aligned with the Globally Harmonized System (GHS) classification for skin corrosion:
- GHS Category 1 - if tissue viability falls below threshold values at defined exposure times.
- GHS Category 1A – Corrosive after ≤3 minutes exposure (most severe).
- GHS Category 1B – Corrosive after >3 minutes and ≤1 hour
- GHS Category 1C – Corrosive after >1 hour and ≤4 hours
- GHS Category 2 or GHS No Category – Not classified as corrosive if viability remains above the threshold.
The MTT ET-50 assay is an in vitro test that evaluates the skin irritation potential of chemicals, formulations, and finished products using Reconstructed Human Epidermis (RhE) models. In this method, the test substance is applied to the tissue, and exposure time leading to a 50% reduction in cell viability (ET-50) is determined through the MTT colorimetric assay.
The ET-50 value provides a quantitative measure of irritation strength, allowing test materials to be classified as non-irritants, mild irritants, moderate irritants, or severe irritants. This assay delivers human-relevant, reproducible results and is widely used in R&D, product development, and safety evaluations.
At MB Research Labs, our experienced scientists apply the MTT ET-50 method to support screening, product optimization, and regulatory submissions. By combining decades of toxicology expertise with advanced 3D human tissue models, we provide clients with reliable, GLP-compliant data while reducing reliance on animal testing.
OECD Test Guideline 498 provides a validated in vitro method for evaluating phototoxicity, the potential of a chemical or formulation to cause skin damage when exposed to light. This assay uses human-derived 3D reconstructed skin models to assess how a test article responds under controlled conditions with and without exposure to simulated sunlight. By measuring changes in tissue viability, OECD TG 498 identifies substances that may trigger light-induced irritation or toxicity.
Skin brightening and pigmentation studies evaluate the ability of ingredients, formulations, and finished products to reduce melanin production or lighten skin tone. Using an advanced 3D human skin model, MelanoDerm™, containing functional melanocytes, these assays replicate the biological processes of pigmentation in vitro. By measuring changes in melanin content, gene expression, and tissue appearance, the test provides reliable, human-relevant data for screening cosmetic and dermatological ingredients.
At MB Research Labs, we apply validated skin brightening assays to support R&D, product development, and marketing claims for cosmetic and personal care products. These models allow clients to assess efficacy, demonstrate product benefits, and bring innovative formulations to market—without the need for animal testing.
Ocular Models
OECD Test Guideline 492 is the internationally recognized in vitro method for assessing eye irritation and serious eye damage without the use of animals. This assay uses Reconstructed Human Cornea-like Epithelium (RhCE) tissue models to evaluate whether a substance may cause ocular irritation or damage. Test articles are applied directly to the tissue, and viability is measured to predict irritation potential.
Results are directly linked to the Globally Harmonized System (GHS) for Classification and Labelling of Chemicals:
- No Category – If tissue viability remains above the threshold, the substance is not classified as an eye irritant.
- Category 1 or 2 (Eye Irritant/Serious Eye Damage) – If viability falls below the threshold, the substance is considered irritating or damaging to eyes.
The MTT ET-50 assay is an in vitro method for evaluating the eye irritation potential of chemicals, formulations, and finished products using human-derived 3D corneal tissue models. In this test, the exposure time required to reduce tissue viability by 50% (ET-50) is determined using the MTT colorimetric assay.
The resulting ET-50 value provides a quantitative measure of irritation strength, allowing substances to be classified as non-irritants, mild, moderate, or severe irritants. Because this method uses human-relevant tissue and delivers reproducible data, it is widely used for R&D screening, formulation optimization, and comparative product testing.
Mucosal Models
The EpiGingival™ model is a 3D human tissue system that replicates the structure and function of the gingival (gum) epithelium. The EpiGingival™ MTT Viability Assay provides a reliable, non-animal method to evaluate the irritation or cytotoxic potential of oral care products, dental materials, chemicals, and medical device extracts that come into contact with gingival tissue.
In this assay, the test material is applied directly to the reconstructed gingival tissue. Cell viability is then measured using the MTT colorimetric assay, which quantifies mitochondrial activity as an indicator of tissue health. A reduction in viability corresponds to irritation or tissue damage, providing human-relevant, reproducible data for safety and product development.
The EpiOral™ model is a 3D human-derived tissue system designed to mimic the structure and function of the buccal/oral epithelium. The EpiOral™ MTT Viability Assay provides a scientifically robust, non-animal method to evaluate the irritation and cytotoxic potential of oral care products, flavoring agents, pharmaceuticals, and medical device extracts intended for contact with the oral cavity.
In this assay, test materials are applied directly to the reconstructed oral tissue. Following exposure, cell viability is measured using the MTT colorimetric assay, which quantifies mitochondrial activity as a marker of cell health. Reduced tissue viability indicates potential for oral irritation or cytotoxicity, delivering human-relevant and reproducible data to support product safety evaluations
For medical devices with oral or mucosal contact, oral irritation testing may be included as part of an ISO 10993 biocompatibility evaluation. These studies provide essential data to demonstrate product safety and support regulatory submissions.
The EpiVaginal™ model is a 3D human tissue system that replicates the structure and function of the vaginal mucosa, providing a reliable non-animal method for assessing irritation potential. EpiVaginal™ irritation testing evaluates whether chemicals, personal care products, lubricants, contraceptives, or medical devices intended for vaginal contact may cause local irritation or tissue damage.
Using human-derived epithelial cells, the assay measures tissue viability, barrier integrity, and histological changes after exposure to a test article. These endpoints provide human-relevant, reproducible data to support product development, formulation optimization, and regulatory safety assessments.
At MB Research Labs, our scientists perform GLP-compliant EpiVaginal™ irritation studies as part of ISO 10993 biocompatibility evaluations and for general safety testing of consumer health products. With decades of expertise in in vitro toxicology, we deliver accurate, regulatory-ready data that helps clients demonstrate product safety while reducing reliance on animal testing
The EpiAirway™ model is a 3D human-derived tissue system that replicates the morphology and barrier properties of the human tracheal/bronchial epithelium. The EpiAirway™ MTT Viability Assay provides a reliable, non-animal method for assessing the potential of test substances—including chemicals, aerosols, consumer products, and medical device extracts—to cause respiratory irritation or cytotoxicity.
In this assay, test articles are applied directly to the airway tissue, and cell viability is measured using the MTT colorimetric method, which quantifies mitochondrial activity as an indicator of cell health. Reduced viability correlates with irritation or toxic effects on the respiratory epithelium, offering human-relevant, reproducible data for product safety and risk assessments.
At MB Research Labs, our scientists routinely perform the EpiAirway™ MTT Viability Assay under GLP conditions, delivering data that supports regulatory submissions, product development, and comparative safety evaluations. With decades of expertise in alternative toxicology, MB Research helps clients meet safety requirements while advancing the 3Rs principle (Replace, Reduce, Refine animal use).
The EpiIntestinal™ model is a 3D human tissue system that replicates the structure and function of the small intestinal epithelium, including absorptive enterocytes and tight junctions. The EpiIntestinal™ MTT Viability Assay provides a reliable, non-animal method to evaluate the irritation, cytotoxicity, or compatibility of pharmaceutical compounds, dietary ingredients, chemicals, and medical device extracts that may come into contact with intestinal tissue.
In this assay, test substances are applied directly to the intestinal tissue model, and cell viability is measured using the MTT colorimetric assay, which quantifies mitochondrial activity as an indicator of cell health. Reduced viability correlates with irritation or tissue damage, providing human-relevant, reproducible data for safety evaluations, absorption studies, and product development.
Frequently Asked Questions
What are tissue models?
Human-derived 3D tissue models are in vitro replicas of specific tissues (e.g., skin, oral, cornea, airway, intestinal) that mimic key structure and function. They enable predictive toxicology, drug discovery, and medical device biocompatibility assessments without animal use.
What are the benefits of using tissue models?
- Higher Human Relevance: Better prediction than 2D cultures and many animal models.
- Reduce Animal Testing: Supports 3Rs and aligns with OECD/ISO/FDA/EPA
- Increased throughput: Screen more compounds with faster turnaround.
- Reproducible data: Standardized tissues and assays improve consistency.
Can my highly pigmented materials be tested with tissue models?
Yes—highly pigmented materials can be tested, but we plan for color interference up front.
Here’s how we handle it so results stay valid:
Interference controls (OECD/ISO-compliant):
- Direct MTT reduction (NSMTT): Run freeze-killed tissues + MTT to quantify any false signal from the test article.
- Non-specific color (NSCl): Run freeze-killed tissues without MTT to correct for dye carry-through in the extract/solvent.
- Apply guideline-specified corrections/acceptance limits before calling the result.
