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...
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...
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...
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...
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)....
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...
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...
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)....
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...
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,...