AbstractThe primary objective of this research was to create injectable delivery formulations using Lactotransferrin (LTF) peptide-loaded dextran nanoparticles coated with docosahexaenoic acid. These nanoparticles, designated as LLDDNP, underwent a lyophilization process. The study encompassed a comprehensive investigation, including physicochemical characterization, in vivo assessment of biomarkers, and an examination of immune response through cytokine modulation. The zeta potential of LLDDNP was − 24.5 ± 12 mV, while their average particle size was 334.9 z.d.nm. The particles exhibited a conductivity of 2.10 mS/cm, while their mobility in the injectable dosage form was measured at − 3.65 µm cm/Vs. The scanning electron microscopy investigation, the lyophilization processes resulted in discrete particles forming particle aggregations. However, transmission electron microscopy analysis revealed that LLDDNP is spherical and smooth. The thermogram showed that about 95% of LLDDNP's weight was lost at 270 °C, indicating that the particles are extremely thermal stable. The XRD analysis of LLDDNP exhibited clear and distinctive peaks at 2θ angles, specifically at 9.6°, 20.3°, 21.1°, 22°, 24.6°, 25.2°, 36°, and 44.08°, providing compelling evidence of the crystalline nature of the particles. According to proton NMR studies, the proton dimension fingerprint region of LLDDNP ranges from 1.00 to 1.03 ppm. The in vitro release of LTF from LLDDNP was found to follow zero-order kinetics, with a commendable R² value of 0.942, indicating a consistent and predictable release pattern over time. The in vivo investigation revealed a significant impact of hepatotoxicity on the elevation of various cytokines, including IL-1β, IL-6, IL-8R, TNF-α, IL-2, IL-4, IL-10, and IFN-γ. Additionally, the presence of hepatotoxicity led to an increase in apoptosis markers, namely caspase 3 and caspase 9, as well as elevated levels of liver biomarkers such as CRP, ALP, ALT, and AST. In contrast, the treatment with LLDDNP modulated the levels of all biomarkers, including cytokines level in the treatment group extremely high significant at p < 0.001.