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Optimizations of the Reconstructed Human Epidermis-Based Phototoxicity Testing to Evaluate the Safety of Long-Lasting Cosmetic Products
January 10, 2025The safety of cosmetic products coming in contact with consumers’ skin is often assessed using New Approach Methodologies, which include Reconstructed human Epidermis (RhE) tissue models that have demonstrated utility as reliable test systems. In our manuscript, we evaluated the phototoxicity potential of long-lasting cosmetic products, such as lipsticks and foundations containing UV-absorbing ingredients. given their design to persist on application areas of skin, technical challenges were encountered in the experiments using RhE tissues as the products could not be...
A Proof-of-Concept for Safety Evaluation of Inhalation Exposure to Known Respiratory Irritants Using In Vitro and In Silico Methods
January 8, 2025There is increased interest in developing non-animal test systems for inhalation exposure safety assessments. However, defined methodologies are absent for predicting local respiratory effects from inhalation exposure to irritants. The current study introduces a concept for applying in vitro and in silico methods for inhalation exposure safety assess- ment. Three in vitro systems, representing the upper (MucilAir™—nasal epithelial tissue) and lower (A549 cells and human precision-cut lung slices) human respiratory regions, were exposed to six respiratory irritants. These irritant exposures were conducted as liquid droplets, aerosol, or...
Building Confidence and Transparency Into a New Validation Paradigm
November 26, 2024For the last two decades, validation management organizations have evaluated new test methods according to the OECD’s Guidance Document 34: Guidance Document On The Validation And International Acceptance Of New Or Updated Test Methods For Hazard Assessment (“GD 34”, 2005, https://doi.org/10.1787/20777876; now under revision)....
Human relevance of in vivo and in vitro skin irritation tests for hazard classification of pesticides
September 24, 2024Test methods to inform hazard characterization and labeling of pesticides to protect human health are typically conducted using laboratory animals, and for skin irritation/corrosion the rabbit Draize test is currently required by many regulatory agencies. Although the Draize test is generally regarded to provide protective classifications for human health, new approach methodologies (NAMs) have been developed that offer more human relevant models that circumvent the uncertainty associated with species differences that exist between rabbits and humans. Despite wide applicability and use of these test methods across...
The Fibrotic Phenotype of Human Precision-Cut Lung Slices Is Maintained after Cryopreservation
September 24, 2024Human precision-cut lung slices (hPCLS) prepared from fibrotic lungs recapitulate the pathophysiological hallmarks of fibrosis. These hallmark features can also be induced by treating non-fibrotic hPCLS with a fibrotic cocktail (FC). As a result, the fibrotic and fibrosis-induced hPCLS are rapidly emerging as preferred models for disease modeling and drug discovery. However, current hPCLS models are limited by tissue viability in culture, as they are usually only viable for one week after harvesting. Here, we demonstrate that the fibrotic hPCLS can be cryopreserved, stored for months,...
Deriving a point of departure for assessing the skin sensitization risk of wearable device constituents with in vitro methods
September 24, 2024Wearable devices are in contact with the skin for extended periods. As such, the device constituents should be evaluated for their skin sensitization potential, and a Point of Departure (PoD) should be derived to conduct a proper risk assessment. Without historical in vivo data, the PoD must be derived with New Approach Methods (NAMs). To accomplish this, regression models trained on LLNA data that use data inputs from OECD-validated in vitro tests were used to derive a predicted EC3 value,...
Approaches to Evaluation of Solvents for use in Photosafety Testing
March 20, 2024New Approach Methodologies (NAMs) are routinely used in photosafety testing to evaluate if a test compound has the potential to become more toxic upon exposure and subsequent exposure to light. Three such NAMs to address photosafety are the in chemico UV-Vis Assay, the cell-based 3T3 Neutral Red Uptake (NRU) Phototoxicity Test (PT), and the tissue-based Reconstructed human EpiDermis (RhE) Phototoxicity Test (PT), described under OECD Test Guidelines (TG) 101, 432, and 498, respectively. These dilution-based assays evaluate the test compound...
Refinement and Optimization of the Photo-KeratinoSens™ Assay to Evaluate Photoallergy Potential
March 20, 2024Identification of test chemicals that have the potential to become more reactive, more toxic, or may become phototoxic upon application and subsequent exposure to sunlight is integral to photosafety testing. Several regulatory-based New Approach Methodologies (NAMs) are widely used in the evaluation of phototoxicity and skin sensitization potential. More recently, there has been an increased interest in ability to identify photoallergens. To this end, an innovative photo-KeratinoSens™ assay was established with addition of an irradiation exposure (5 J/cm2 of UVA)...
SOT 2024 Newsletter
February 28, 2024Please visit us at booth #1232 during ToxExpo. We have exciting information to share about new assays, test guidelines and more! In attendance will be: Amanda Ulrey (President), Kristie Sullivan (VP of Education and Outreach), Hans Raabe (COO), Holger Behrsing (Director of Respiratory Services), Vivek Patel and Allison Hilberer (Study Directors) and Brent Gilbert (Director of Business Development). Email us at clientservices@iivs.org to arrange a meeting with any members of our team....
January 2024 Newsletter
January 26, 2024Coming soon to IIVS: The Reactive Oxygen Species (ROS) Assay for photoreactivity, a cost effective, high throughput approach that can screen test compounds of interest without the immediate need for more comprehensive (and expensive) assays. ...