Author: Mitchell Gaydash

Human relevance of in vivo and in vitro skin irritation tests for hazard classification of pesticides

September 24, 2024
Test 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, 2024
Human 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, 2024
Wearable 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, 2024
New 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, 2024
Identification 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)...

IIVS 2023 Impact Report

March 20, 2024
I am happy to present to you the Institute for In Vitro Sciences' (IIVS) 2023 annual report, marking my first year serving as President. It has been an honor to lead the IIVS team through a period of growth and transformation, and I am excited to share with you the progress we have made in advancing new approach methodologies in toxicological research. In addition to my appointment, we welcomed Kristie Sullivan, MPH to our team as the Vice President of...

SOT 2024 Newsletter

February 28, 2024
Please 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, 2024
Coming 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.      ...

October 2023 Newsletter

January 26, 2024
Recording of the two-part webinar series on in vitro phototoxicity, co-organized by IIVS and PETA Science Consortium International, now available online.          ...

Toxicity and Inflammatory Response to Common Magic Mouthwashes in a 3D Oral Reconstructed Tissue Model

November 8, 2023
Magic Mouthwash is a general term describing oral rinses prescribed by a doctor for the treatment of pain, inflammation, or infection, commonly as a result of chemotherapy and radiation induced oral sores (oral mucositis). There is no set combination of ingredients for the preparation of a magic mouthwash, rather they are formulated for the individual needs of each patient, selecting from an array of various active ingredients. Although the ingredients most commonly used to formulate Magic Mouthwashes are considered safe as prescribed, the final formulations lack toxicity...