Immersion of nanostructured lipid carriers loaded with 17-alpha methyltestosterone for masculinization of red tilapia (Oreochromis sp.)

The present study aimed to develop novel masculinization agents for enhancing sex-reversal in red tilapia (Oreochromis sp.) by immersion administration using 17α-methyltestosterone-loaded nanostructured lipid carriers (MT-NLC). Moreover, the surface charge of the MT-NLC was modified with chitosan (CS-MT-NLC) to improve their mucoadhesive property. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to characterize the morphology of the nanoparticles. Furthermore, we assessed the toxicity associated with immersion-induced masculinization in red tilapia. Subsequently, we examined alterations in gill morphology, determined the percentage of masculinization, analyzed their length-weight relationship, and investigated the expression of genes related to sex differentiation. MT-NLC had an average size, polydispersity index, and negatively charged surface of 140.8 ± 2.6 nm,