VALIDATING MTS AS AN ALTERNATIVE VIABILITY ASSAY TO MTT ON THE HUMAN 3-D TISSUE MODELS, EPIAIRWAY AND EPIDERM.
This study by researchers at the State University of New York (SUNY) at Stony Brook documents the development of an alternative tissue viability endpoint analysis using the non-lytic agent MTS in place of the industry-standard MTT for MatTek’s EpiAirway in vitro 3-D human tracheal/bronchial tissue equivalent and MatTek’s EpiDerm in vitro 3-D human skin tissue equivalent, thereby allowing users to preserve the tissues on which the viability assay was performed, permitting subsequent assays to be performed on those same tissues. Organotypic 3-D models are often used for drug development and product testing. Our own research group frequently evaluates nasal drug formulations, cosmeceutical components, and transdermal delivery systems with MatTek’s commercially produced 3-D air-lifted models, including EpiAirway™, EpiDerm™, EpiDermFT™, and MelanoDerm™. End point viability assays play an essential role in these studies in determining the validity of our results. The standard method to measure endpoint viability for use with these models is the MTT assay. However, MTT requires lysis of the tissue in order to release the colored formazan product for optical density analysis. This destruction of the tissue effectively ends a given study and precludes any further analysis of tissue contents or responses, including the levels of tissue resident drug, tissue protein or nucleic acid levels, or histology. MTS, a tetrazolium salt based assay, similar to MTT, is reduced by metabolic activity to a soluble formazan product. The soluble product of MTS enables the user to preserve the tissue so that subsequent assays can be performed on the exact tissue the viability assay was done on. We have established a protocol for the use of MTS with the 3-D tissue model EpiAirway and are continuing to develop guidelines for another MatTek model: EpiDerm. MTS has proved to be a reliable and non-lytic alternative to MTT. We have designed a protocol for use on three-dimensional EpiAirway models, which has stood the test of numerous repetitions proving the reproducibility of the assay. Repetitions of the EpiDerm studies are on-going to validate the protocol. MTT incubation endpoints for these will be done at MatTek’s documented endpoint of 180 min.
AIR-100, EPI-200, EpiAirway, EpiDerm, MTS, a tetrazolium salt based assay, MTT assay, MTT signal development
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