Recent work has shown the presence of nanoplastics and microplastics within the human placenta, and nanoplastics have been observed to cause damage to developing mammalian fetuses. Our findings can instruct the design of more biocompatible PCL and other biomaterials, in general, by applying new approach methodologies and non-targeted bioassays to assess biocompatibility. Zebrafish have been demonstrated as effective platforms for studying the foreign body response to biomaterials and developing engineered tissues because of their optically transparent transgenic lines and rapid development. Non-targeted bioassays can screen for dysregulation of biological processes resulting from biomaterial exposure to identify formulations that minimize adverse effects. In particular, TF-FACTORIAL and NR-FACTORIAL bioassays can reveal when treatments (pharmaceutical or otherwise) deviate from their desired activity. Environmental PCL is often derivatized, modified, or blended with other polymers (e.g., PLA and polyvinyl chloride) to tailor a plastic's degradability and mechanical properties. Additionally, PCL satisfies many degradability standards, 137 has received FDA food-contact approval when blended with PLA, 140 and is used in many biomedical devices. For these reasons, as industry moves toward more degradable, ecocompatible 141 plastics, the use of PCL is likely to increase.