In vitro tagging of embryos with nanoparticles

Purpose: To develop an in vitro method for tagging embryos and to compare the development of the embryos after nanoparticles injection versus externally-applied nanoparticles derived from either polystyrene or polyacrylonitrile. Methods: Each mouse 1-cell embryo (the selected test-model) was either: (a) injected by intracytoplasmic injection or (b) co-incubated with different nanoparticles at 37°C, 5% CO₂ in air. The embryos were assessed after 2 and 6 days of culture. Results: Embryo development was similar for externally-applied polystyrene nanoparticles and control (97.6 ± 2.7 versus 100.0 ± 0%) but different for polyacrylonitrile nanoparticles (90.0 ± 2.8 %) on day 2. However, the results were similar on Day 6. Injected embryos were linked to lower percent development on Day 2. Few injected embryos reached blastocyst stage on Day 6 after a brief UV-fluorescence exposure. Conclusions: Tagging embryos by external polystyrene-based nanoparticles was the better method when compared with injected nanoparticles. Larger nanoparticles in microsphere range were easier to qualitate. Inhibited hatching limited their use beyond the blastocyst stage.