Dental resins used in 3D printing technologies release ovo-toxic leachates

We recently engineered the first female reproductive tract on a chip (EVATAR), to enable sex-based ex vivo research. To increase the scalability and accessibility of EVATAR, we turned to 3D printing (3DP) technologies, selecting two biocompatible 3DP resins, Dental SG (DSG) and Dental LT (DLT) to generate 3DP microphysiologic platforms. Due to the known sensitivity of reproductive cells to leachable compounds, we first screened for toxicity of these biomaterials using an in vitro mammalian oocyte maturation assay. Culture of mouse oocytes in 3DP plates using conventionally treated DSG resin resulted in rapid oocyte degeneration. Oxygen plasma treatment of the surface of printed DSG resin prevented this degeneration, and the majority of the resulting oocytes progressed through meiosis in vitro. However, 57.0% +/- 37.2% of the cells cultured in the DSG resin plates exhibited abnormal chromosome morphology compared to 19.4% +/- 17.3% of controls cultured in polystyrene. All tested DLT resin conditions, including plasma treatment, resulted in complete and rapid oocyte degeneration. To identify the ovo-toxic component of DLT, we analyzed DLT leachate using mass spectroscopy. We identified Tinuvin 292, a commercial light stabilizer, as a major component of the DLT leachate, which resulted in a dose-dependent disruption of meiotic progression and increase in chromosomal abnormalities with oocyte exposure, showing significant ovo-toxicity in mammals. Severe reproductive toxicity induced by in vitro exposure to these 3D-printed resins highlights potential risks of deploying insufficiently characterized materials for biomedical applications and underscores the need for more rigorous evaluation and designation of biocompatible materials. (C) 2021 The Authors. Published by Elsevier Ltd.