Author: Mitchell Gaydash

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...

Safety Assessment of Monographed OTC Cold/Cough Medicine Using an In Vitro Testing Platform Based on Human Reconstructed Oral Tissues

November 8, 2023
Over-the-counter (OTC) products are available to alleviate concurrent symptoms of colds and flu. They are primarily based on a combination of decongestants, antitussive and alpha adrenergic agonists, which are well-established pharmaceutical agents covered by U.S. monographs. Many of the active components of the OTC cough/cold drugs are bitter and must be masked using flavoring agents. Bayer internally employed a stringent safety testing program for OTC cough/cold medicine line extensions that require the products to be held in the mouth for a short period using an...

The Importance of Supplier Qualification for Vendors of Materials Used in In Vitro Assays

November 7, 2023
Pre-clinical assays, including in vitro assays, rely heavily on suppliers who provide essential products or services. In the current regulatory environment, the burden is placed on the users of these products or services to ensure that the methods employed at the suppliers' facilities meet a sufficient level of quality. Variable results for the same assay controls over time could indicate high lot-to-lot variability of the test system or of critical assay components. Though monitoring assay controls is useful to help...

Cryopreserved human precision-cut lung slices provide an immune competent pulmonary test system for “on-demand” use and long-term cultures

October 20, 2023
Human precision-cut lung slices (hPCLS), considered a highly relevant ex vivo model of the lung, offer native architecture and cells of the lung tissue including respiratory parenchyma, small airways, and immune competent cells. However, the irregular availability of donor lungs has limited the accessibility of this system. As described here, thousands of hPCLS can be created from 1 lung, cryopreserved, and used “on demand” by applying slicing and cryopreservation methodology improvements. Fresh and cryopreserved (~7 and ~34 weeks; F&C) hPCLS...