Inorganic Nanoparticles in Reproduction Biology: Opportunities and Challenges

The development of inorganic metal and metal oxide nanoparticles (MNPs) has attracted significant attention in biomedical and biotechnological fields. An emerging field in this context is the use of MNPs in reproduction biology. Here, we review the development of MNPs in the field of reproduction by focusing on their interactions with highly delicate and specialized germ cells like spermatozoa and oocytes as well as developing embryos. By their unique physicochemical properties, MNPs are good candidates for targeted imaging and delivery of biofunctional molecules to the specific sites of the gametes and reproductive cells. Furthermore, functionalized MNPs can serve as transfection vectors for the generation of transgenic animals by sperm‐mediated gene transfer (SMGT) in artificial insemination or in vitro fertilization. In addition, MNPs have shown great promise in application fields such as semen collection, nano‐purification, cryopreservation, and sex sorting of sperm in the livestock industry. The article includes an in‐depth discussion on the uptake, translocation mechanism, and bioresponse of the MNPs to reproduction‐relevant sites on the clinical, cellular, and molecular levels. Based on these promising achievements, the current challenges and prospects of the development of these functionalized MNPs for clinical research in conjunction with the reproductive system will be discussed.