Author: Mitchell Gaydash
Micronucleus Induction by 5-Methoxypsoralen in the Photo Reconstructed Skin Micronucleus Assay
March 28, 2025To address a lack of suitable non-animal tools to screen novel ingredients in personal care products for mutagenic/clastogenic activity after solar light exposure, we initiated a three-phase program to develop a new approach methodology (NAM) which integrates established UVA/UVB/visible light (UV/vis) photo-activation techniques to the reconstructed skin micronucleus (RSMN) assay. The first phase of the program established a repeat exposure photo- irradiation schedule in reconstructed human epidermal (RhE) tissues, and the second phase was conducted to identify a photo-genotoxic substance...
Addressing Key Factors in Cryopreservation Method Development Ensures Robust Performance for Human Precision-cut Lung Slices
March 28, 2025As new approach methodologies (NAMs) are increasingly explored to identify dependable and accurate non-animal alternatives to predict human toxicities, several 3-dimensional test systems have emerged as excellent models of the human respiratory tract. Among these, human precision-cut lung slices (hPCLS) are considered highly relevant, containing many cell types (including key immune cells), small airways, and respiratory parenchyma in a native architecture configuration. Despite their excellent representation of the deep lung, limited accessibility to fresh (non-transplantable) human donor lungs has hampered...
Genotoxicity Evaluation of Fragrances and Botanicals using ToxTracker Assay
March 28, 2025The ToxTracker® assay has gained attention as a second tier non-animal test method to the standard battery of in vitro genotoxicity assays by providing mechanistic insights into the modes of action including DNA damage, oxidative stress, cellular stress, protein damage, and the validated method is currently undergoing review at the OECD level for acceptance within international regulatory frameworks. As such, ToxTracker® is designed to identify both genotoxic and non-genotoxic carcinogens, thus providing industry and regulatory toxicologists with highly useful information...
Transfer and Refinement of the Reactive Oxygen Species (ROS) Assay to Evaluate Photoreactivity Potential
March 28, 2025Photoreactivity evaluation is one of the initial screenings in a photosafety assessment that can identify compounds which may have the potential to produce various types of adverse photo reactions, including photoirritation (or phototoxicity), photoallergy, and photogenotoxicity. The Reactive Oxygen Species (ROS) Photoreactivity Assay, adopted under OECD Test Guideline (TG) 495, is an in chemico test system that measures the amount of ROS generated by a test compound upon exposure to simulated sunlight. The generation of ROS is determined through measurement...
Introducing a New Photoreactivity Assay
March 12, 2025IIVS is excited to announce the successful transfer of the Reactive Oxygen Species (ROS) photoreactivity assay into our laboratory. This high-throughput, in chemico screening assay, adopted as OECD Test Guideline 495, is designed to assess photoreactivity potential of test substances through measurement of two ROS: singlet oxygen (SO) and superoxide anion (SA)....
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...
November 2024 Newsletter
January 8, 2025Our Respiratory Toxicology team has had a productive year, staying at the forefront of the latest industry developments while also contributing new insights of our own. We've had the opportunity to attend and present at key conferences, as well as showcase the exciting progress we're making in advancing in vitro toxicology testing....
September 2024 Newsletter
January 8, 2025If you will be at EUROTOX, September 8-11, stop by BOOTH #34 to speak with IIVS President, Amanda Ulrey and meet our new Client Relationship Manager Joseph Hughes. We have some new methods available for GLP use now and several others that are currently in the technology transfer phase. We look forward to catching up with you there....
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)....