Efficient cellular penetration and biocompatibility of FE23-Functionalized Magnetite Nanoparticles: A promising platform for targeted drug delivery

Abstract

Nanoparticles (NPs) are garnering increased interest as a means to develop highly penetrative vehicles capable of addressing the issue of low permeability associated with various pharmacological agents across biological barriers. A critical challenge in this field is enabling NPs to effectively cross the cell membrane and escape endosomal pathways during intracellular trafficking, thereby enhancing the bioavailability of active compounds. This study focuses on magnetite nanoparticles (MNPs) functionalized with the rationally designed peptide FE23. MNPs were prepared using the co-precipitation method and characterized based on their size, surface charge, and biocompatibility. Dynamic light scattering (DLS) measurements revealed average hydrodynamic diameters and surface charges of 100 ± 40.91 nm and 35.34 ± 0.76 mV for bare MNPs, and 140 ± 70.74 nm and 32.16 ± 1.09 mV for MNPs-FE23 at pH 4.5. The morphology and size of the nanoparticles were further confirmed through scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imaging. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were employed to verify the successful immobilization of the FE23 peptide onto the MNPs. The biocompatibility of the resulting nano-bioconjugates was assessed through hemolysis, platelet aggregation, and cytotoxicity assays to evaluate their potential as bioactive molecule carriers and cell-penetrating agents. Hemolysis levels remained below the 5% ISO standard, while platelet aggregation was approximately 10%, indicating a low risk of blood clot formation. Cytotoxicity was minimal, with cell viability remaining above 80% in both tested cell lines after 24 hours and decreasing only slightly after 48 hours. Finally, the cellular uptake and endosomal escape capabilities of the MNPs-FE23 were evaluated in different cell lines, yielding promising results for both cases. In summary, this study presents the synthesis, characterization, and functionalization of magnetic nanoparticles conjugated with a highly translocating peptide, demonstrating their potential for use in novel drug delivery systems within the nanobiotechnology field.