Currently there is a growing intere

Currently there is a growing interest in the use of nanotechnology in reproductive medicine and reproductive biology. However, their toxic effects on mammalian embryos remain poorly understood. In this work, we evaluate the biocompatibility of two fibrous nanomaterials (NMs): cotton cellulose nanofibers (CNF) and carboxylated multiwalled carbon nanotubes (MWCNT-COOH), by performing an investigation of the embryonic development, gene expression (biomarkers focused on cell stress, apoptosis and totipotency) and in situ apoptosis in bovine embryos. Exposure to NMs did not interfere in preimplantation development or in the incidence of apoptosis in the bovine embryo, but they did affect the gene expression. The results presented are important for an understanding of the toxicity of cotton CNF and MWCNT-COOH on mammalian embryos. To our knowledge, we report the first evaluation of biocompatibility between these NMs on preimplantation embryos, which may open a new window for reproductive biomedical applications.