Comparative Study of Larvicidal Activity of Spinel Co3O4 Nanorods and Entomopathogenic Metarhizium brunneum Conidia against Culex pipiens.

Herein, we report the synthesis of spinel cobalt oxide nanorods (Co3O4 NRs) by a modified co-precipitation approach and examine their larvicidal activity against Culex pipiens. The structure and morphology of the as-prepared Co3O4 NRs were emphasized using X-ray diffraction (XRD), Raman spectroscopy, energy dispersive X-ray spectroscopy (EDAX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). It was found that Co3O4 nanostructures have a face-centered spinel cubic crystal structure with a mean crystallite size of 38 nm. These nanostructures have a rod like shape with a mean diameter of 30 nm and an average length of 60 nm. The TGA measurements revealed the high stability of the formed spinel cubic structure at 400 °C. The optical behavior indicates the direct transition of electrons through an optical band gap in the range of 2.92-3.08 eV. These unique chemical and physical properties of Co3O4 NRs enabled them to be employed as a strong agent for killing the C. pipiens. A comparison study was employed between the as-prepared Co3O4 and the entomopathogenic fungus Metarhizium brunneum as a control agent of C. pipiens larvae. The results revealed that the as-prepared nanorods have higher mortality against C. pipiens larvae compared with the well-known M. brunneum.

Nanoparticles as a novel and promising antiviral platform in veterinary medicine.

Traditional veterinary virus vaccines, such as inactivated and live-attenuated vaccines, have achieved tremendous success in controlling many viral diseases of livestock and chickens worldwide. However, many recent viral outbreaks caused by different emerging and re-emerging viruses continue to be reported annually worldwide. It is therefore necessary to develop new control regimens. Nanoparticle research has received considerable attention in the last two decades as a promising platform with significant success in veterinary medicine, replacing traditional viral vector vaccines. However, the field of nanoparticle applications is still in its initial phase of growth. Here, we discuss various preparation methods, characteristics, physical properties, antiviral effects, and pharmacokinetics of well-developed nanoparticles and the potential of nanoparticles or nano-vaccines as a promising antiviral platform for veterinary medicine.