Establishing a safe and effective cleaning method for PDMS devices derived from 3D-printed resin moulds in embryo production.

Dynamic systems for in vitro embryo production (IVEP) have long been sought to allow a higher resemblance to the physiological conditions of the oviduct and uterus. Although significant progress has been demonstrated in the microfluidic field, some challenges are still present regarding the microfluidic devices' sterilization protocol. This complication is related to the leached components from the poly(dimethylsiloxane) (PDMS). The PDMS is one of the safest materials used in soft lithography for embryo production. However, the use of moulds required for soft lithography can compromise embryo culture. This limitation arises from the restricted range of biocompatible resins available for 3D-printing of moulds. While the replacement of the biomaterial for mould production is not a straightforward option, we hypothesized that PDMS devices fabricated from such moulds could be rendered biocompatible through an optimized cleaning protocol. In this current study, we evaluated the effectiveness of sequential washes, sonication, and extended incubation in washing solutions. Our results demonstrate that a prior incubation of the PDMS devices in PBS supplemented with antibiotics and antifungal (at 4°C for 48 hours), in addition to the incubation in IVC medium (at 38.5°C for 48 hours), enables bovine embryo development within PDMS devices fabricated with moulds from a 3D printer. This optimized protocol supported IVEP at rates equivalent to standard conditions, with no increase in apoptosis or oxidative stress, validating its suitability for artificial reproductive techniques applications.