TRITC-Loaded PLGA Nanoparticles as Drug Delivery Carriers in Mouse Oocytes and Embryos

The structural layers around oocytes make it difficult to deliver drugs aimed at treating infertility. In this study, we sought to identify nanoparticles (NPs) that could easily pass through zona pellucida (ZP), a special layer around oocytes, for use as a drug delivery carrier. Three types of NPs were tested: quantum dot NPs, PE-polyethylene glycol (PEG)-loaded poly(lactic-co-glycolic acid) (PLGA) NPs (PEG/PL), and tetramethylrhodamine-loaded PLGA NPs (TRNPs). When mouse oocytes were treated with NPs, only TRNPs could fully pass through the ZP and cell membrane. To assess the effects of TRNPs on fertility and potential nanotoxicity, we performed mRNA sequencing analysis to confirm their genetic safety. We established a system to successfully internalize TRNPs into oocytes. The genetic stability and normal development of TRNP-treated oocytes and embryos were confirmed. These results imply that TRNPs can be used as a drug delivery carrier applicable to germ cells.