To address ocular device induced phototoxicity, an in vitro 3T3 Neutral Red Uptake Phototoxicity test (OECD 432) for chemicals has been modified. Soft contact lenses formulated with three different photo-absorbing compounds and chemical solutions of these compounds were evaluated.
Alternative methods, including the validated 3T3 Neutral Red Uptake (NRU) Phototoxicity assay (OECD TG 432) may be used as a pre-clinical test to address phototoxicity. Currently, there are no validated alternative test methods to identify photoallergens; however, there are several validated alternative test methods to address skin sensitization, including the Direct Peptide Reactivity Assay (DPRA) (OECD 442C). To address photoallergy, we utilized the 3T3 Phototoxicity assay in combination with a modified photo-DPRA assay to determine if these assays were able to 1) identify compounds with phototoxicity potential and 2) discriminate between photoirritants and photoallergens.
Robust non-animal models and assays for pulmonary toxicology are required to make competent product development and risk assessments for new materials requiring toxicity testing. Three in vitro assays (goblet cell hyperplasia , ciliary beat frequency , and MUC5AC quantitation) were evaluated for performance and reproducibility. To assess these assays, 6 laboratories contributed data using a common protocol utilizing IL-13 as an inducer of adverse mucociliary-relevant tissue changes. MatTek EpiAirway™ and Epithelix MucilAir™ 3D tissue models were used to evaluate endpoints using histology for GCH, software-based applications, Cilia FA and SAVA, for CBF, and ELISA assay for MUC5AC.
E-vapor product liquids contain a variety of ingredient combinations that should be assessed for human risk. One human lung-relevant testing platform with reasonable throughput, is human precision-cut lung slices (HuPCLS). HuPCLS are arguably the most complex non-animal model of the lung, retaining native architecture and immune-competent cells over multi-week culture periods. HuPCLS were exposed to three concentrations (0.1%, 0.5%, and 1.2%) of propylene glycol (PG; an E-vapor product constituent) continuously for 16-days. Exposure-effects were evaluated biochemically (WST-8 assay) and histologically (viability assessment of H&E stained slides). Positive control treatments consisted of 10 µM Phortress and 13 µM bleomycin.
While data are still being collected and analyzed, there were at least 1,300 accidental electronic liquid (e-liquid) exposures reported as of 2013. Deaths have occurred as a result of ingestion of e-liquid with the effects being attributed primarily to nicotine. The Food and Drug Administration (FDA) sought to regulate e-liquid through the Tobacco Control Act passed in 2009. In 2014, the FDA issued its “Deeming” proposals for public comments, which covered e-liquid manufacturing; the Final Rule giving the FDA authority to regulate e-liquids was released on May 5th, 2016. This study investigated the oral irritation of 3 different formulations of e-liquid using an in vitro time course assay in the reconstructed tissue model EpiOral™ (MatTek Corporation, Ashland, MA, USA). All products were from the same manufacturer, contained 1.2% nicotine and differed only in their flavorings.
The US-FDA has regulatory authority over tobacco products, including conventional cigarettes and next generation products (NGPs) such as e-cigarettes and tobacco heating products (THPs). There is a desire by the industry, regulator and animal protection organizations to incorporate non-animal test methods for tobacco product and NGP assessment. When assessing respiratory effects in vitro, reliable exposure systems that deliver aerosols to cellular/tissue cultures at the air-liquid interface are needed.
The use of non-whole animal test methods transforms the way regulatory requirements are applied in preclinical testing. Recent global regulatory initiatives emphasize the importance of transitioning to human relevant assays and test systems that do not use animals. When these methods are moved from research into the regulated arena, GLP principles must be followed. The GLPs were originally written in the 1970s, when the vast majority of regulated research was performed using animals as the test system. Current innovative, alternative test systems include ex vivo tissues, manufactured biological systems, three dimensional tissue constructs, and cell cultures maintained in dynamic flow bioreactors. Each type of alternative test system raises new quality and compliance points to consider when used within a regulatory context. Just as the applications of these methods have advanced with regulatory acceptance, the quality control and compliance of these test systems must also progress.
This poster provides a snapshot of pre-college teachers (46) within the U.S.—gauging their knowledge and familiarity of the 3Rs and non-animal testing methods (i.e. in vitro methods), initiative to address the topic in the classroom, and their students’ level of interest in the topic. While recognizing the ethical considerations related to animal experimentation, the current generation of teachers and students are also eager to understand the relevance, reliability, and reproducibility of in vitro methods as the modern wave of technologies in toxicology, and possible replacement of animal use for testing purposes. Our data indicate an education field eager to learn about new concepts that might impact our daily activities in an ethical way, and to get up to speed with advances in science.
Three regulatory accepted in vitro assays were evaluated in a proof-of-concept project to determine skin sensitization potential of electronic cigarette liquids (eliquids). These assays measure molecular initiating events and initial cellular responses prescribed in the OECD Integrated Testing Strategy (ITS) describing key events in the adverse outcome pathway (AOP) leading to skin sensitization.