Silver selenide (Ag2Se) is a promising nanomaterial due to its outstanding optoelectronic properties and countless bio-applications. To the best of our knowledge, we report, for the first time, a simple and easy method for the ultrasound-assisted synthesis of Ag2Se nanoparticles (NPs) by mixing aqueous solutions of silver nitrate (AgNO3) and selenous acid (H2SeO3) that act as Ag and Se sources, respectively, in the presence of dissolved fructose and starch that act as reducing and stabilizing agents, respectively. The concentrations of mono- and polysaccharides were screened to determine their effect on the size, shape and colloidal stability of the as-synthesized Ag2Se NPs which, in turn, impact the optical properties of these NPs. The morphology of the as-synthesized Ag2Se NPs was characterized by transmission electron microscopy (TEM) and both α- and β-phases of Ag2Se were determined by X-ray diffraction (XRD). The optical properties of Ag2Se were studied using UV–Vis spectroscopy and its elemental composition was determined non-destructively using scanning electron microscopy–energy-dispersive spectroscopy (SEM–EDS). The biological activity of the Ag2Se NPs was assessed using cytotoxic and bactericidal approaches. Our findings pave the way to the cost-effective, fast and scalable production of valuable Ag2Se NPs that may be utilized in numerous fields.

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: The application of nanotechnology to stem cell research and development has made great strides during the last years. Nanotechnology offers a new opportunity for research and development of stem cells. The mammary gland is a dynamic organ that undergoes extensive morphogenesis during the different stages of embryonic development, puberty, pregnancy, lactation and involution. There are multipotent stem cells that reside in mammary tissue (MaSCs) with the ability to self-renew and even differentiate into all types of mammary cells. To identify, characterize, and differentiate MaSCs, a variety of methods have been used to understand the signal transduction pathways that promote their self-renewal and their cellular fate. In the last decade, stem cell therapy has become a promising and modern topic of scientific research, which has raised great expectations. However, by itself, it presents some problems that have been overcome with the use of nanoparticles (NPs). A triple function has been accomplished: transport of drugs or biomolecules that help in the differentiation and proliferation of stem cells, cell targeting and contrast agents for real-time monitoring and obtaining bioimages for diagnostic and detection systems. The main objective of applying stem cells in conjunction with NPs is to control cellular activity, mainly the regenerative capacity of mammary tissue against diseases such as mastitis or to optimize milk production. In this review, we provide a current overview of the application of nanomaterials on stem cells, specifically bovine stem cells in both the mammary gland and milk, as they are a potential source of cell progenitors with potential characteristics and could be used in potential therapies based on with these cells.