In Vitro and in Vivo Characterization of Inosine Monophosphate Delivered by a Nanoparticle in Rainbow Trout

Abstract

Rainbow Trout Oncorhynchus mykiss are a commonly farmed fish worldwide and, as such, are of economic importance in many countries. Inosine monophosphate (IMP) has been shown to have a positive effect on Rainbow Trout growth performance and overall health. The aim of the current study was to test whether a novel phytoglycogen nanoparticle (NP) was nontoxic and if it could enhance the positive effects of IMP on Rainbow Trout health at the cellular and whole-animal level. The NP used in this study is derived from sweet corn and can act as a carrier, delivering its payload to the cell. The NP was chemically modified to covalently bind IMP. The effects of four experimental groups were tested on Rainbow Trout at the in vitro and in vivo level: untreated control, NP alone, IMP alone, and IMP covalently conjugated to the NP (IMP-NP). The effects of the four experimental groups were measured at the cellular level using a Rainbow Trout intestinal epithelial cell line (RTgutGC). Cellular metabolism was significantly increased in RTgutGC when treated with IMP-NP for 24 and 48 h compared with NP or IMP alone. These treatments did not result in a compromised cell membrane, with the exception of minimal membrane integrity loss at 48 h with the higher doses of IMP-NP. During the 48-h time frame, enhanced metabolism did not result in enhanced cell proliferation. A pilot study was performed in Rainbow Trout to test the safety of the NP to fish. Over an 8-week feeding trial, no mortalities were observed. Additionally, intestinal villi density increased with IMP-NP and NP treatments, while villus height and width were unaffected. This study introduces the use of a phytoglycogen-based NP as a novel delivery system for IMP that is able to increase metabolism at the cellular level and is nontoxic in Rainbow Trout.

More tools for our toolkit: The application of HEL-299 cells and dsRNA-nanoparticles to study human coronaviruses in vitro

“…In fact, nanoparticles of various compositions have shown promise as carriers of poly inosinic: poly cytidylic acid (pIC), a commercially available viral dsRNA mimic, while effectively stimulating the immune system ( Kim et al, 2017 ; Sokolova et al, 2017 ; Gondan et al, 2018 ). Because nanoparticles of inorganic composition can have negative impacts on cells and their responses ( Jeng and Swanson, 2006 ; Villeret et al, 2018 ; Báez et al, 2021 ; reviewed by Sengul and Asmatulu, 2020 ), optimization with an organic nanoparticle, such as the phytoglycogen nanoparticle (NDX) previously used by our group ( Alkie et al, 2019 ; Jenik et al, 2021a ; Jenik et al, 2021b ), would be ideal. Previous work has shown that this phytoglycogen nanoparticle is non-toxic, can effectively deliver pIC to vertebrate cells, and can successfully limit rhabdovirus replication ( Alkie et al, 2019 ).…”