Masculinization of Red Tilapia (Oreochromis spp.) Using 17-Methyltestosterone-Loaded Alkyl Polyglucosides Integrated into Nanostructured Lipid Carriers

Simple Summary Lipid-based nanocarriers have proved effective for drug and hormone delivery. The androgen hormone 17 alpha-methyltestosterone (MT) is used for sex reversal in tilapia; however, the hormone has biopharmaceutical limitations such as insolubility, low stability, limited intestinal absorption, and poor bioavailability. Incorporating MT into lipid-based nanocarriers to improve hormone uptake in tilapia is an interesting prospect. In the present study, we reported an improved version of alkyl polyglucosides loaded with 17 alpha-methyltestosterone integrated into nanostructured lipid carriers (APG-NLC) for the masculinization of red tilapia (Oreochromis spp.) via oral administration as a feed additive. We demonstrated that nanotechnology-based drug delivery systems represent a novel and promising strategy for improving the oral absorption of these androgen hormones, resulting in a 50% w/w reduction in the hormonal dosage during the sex reversal period. Therefore, we strongly believe that this newly optimized nanotechnology is one of the solutions for sustainable aquaculture production. The aim of the present study was to optimize a masculinization platform for the production of all-male red tilapia fry by oral administration of 30 and 60 ppm of MT and alkyl polyglucoside nanostructured lipid carriers (APG-NLC) loaded with MT, respectively, for 14 and 21 days. The characterization, encapsulation efficiency and release kinetics of MT in lipid-based nanoparticles were assessed in vitro. The results showed that the MT-loaded nanoparticles were spherical, ranging from 80 to 125 nm in size, and had a negative charge with a narrow particle distribution. The APG-NLC loaded with MT provided higher physical stability and encapsulation efficacy than the NLC. The release rate constants of MT from MT-NLC and MT-APG-NLC were higher than those of free MT, which is insoluble in aqueous media. There was no significant difference in survival between the fish administered MT or the those fed orally with MT-APG-NLC fish. According to the logistic regression analysis, the sex reversal efficacy of MT-APG-NLC (30 ppm) and MT (60 ppm), resulted in significantly higher numbers of males after 21 days of treatment compared with the controls. The production cost of MT-APG-NLC (30 ppm) after 21 days of treatment was reduced by 32.9% compared with the conventional MT treatment group (60 ppm). In all the treatments, the length-weight relationship (LWR) showed negatively allomeric growth behavior (b < 3), with a relative condition factor (K-n) of more than 1. Therefore, MT-APG-NLC (30 ppm) would seem to be a promising, cost-effective way to reduce the dose of MT used for the masculinization of farmed red tilapia.