A comprehensive study on doxorubicin-loaded aspartic acid-coated magnetic Fe3O4 nanoparticles: Synthesis, characterization and in vitro anticancer investigations

Magnetic Fe3O4 nanoparticles (MNPs) hold significant potential across various scientific fields due to their notable properties. For biomedical applications, MNPs must be biocompatible, stable, and possess high magnetic potential. Aspartic acid (ASP) as a coating agent not only provides biocompatibility, stability, and high magnetic potential but also offers the potential for absorbing various drugs for targeted delivery due to its carboxyl and amino functional groups. So, in this study, we synthesized ASP-coated MNPs (ASP-MNPs) through a one-step co-precipitation method and loaded doxorubicin (DOX) onto these nanoparticles to create DOX-ASP-MNPs for targeted drug delivery. Characterization of the nanoparticle confirmed the crystal structure, spherical morphology, and improved size distribution of ASP-MNPs (8.53 +/- 2.56 nm) compared to uncoated MNPs (7.05 +/- 1.89 nm), as analyzed by XRD, FESEM, and TEM. FT-IR and zeta potential assessments (ZP = -6.3 mV for MNPs, ZP = -31.1 mV for ASP-MNPs) verified successful ASP binding, DOX loading, and nanoparticle stability. VSM analysis indicated a slight decrease in saturation magnetism after coating (51.1 emu/g) compared to MNPs (57.4 emu/g). In vitro release studies demonstrated a higher release rate (83 %) of DOX-ASP-MNPs at pH 5.2, indicating their suitability for cancerous cells. Cytotoxicity assays on A-549 cancer cell lines showed a dose-dependent response. DAPI staining revealed that free DOX caused more DNA damage. Cellular uptake studies indicated a time-dependent uptake of DOX-ASP-MNPs, higher at 3 h compared to 1 h, though lower than free DOX uptake due to different uptake pathways. Apoptosis assays over 72 h showed similar apoptotic rates for DOX-ASP-MNPs and free DOX. These findings suggest that ASP-MNPs possess enhanced physicochemical properties and effective drug delivery capabilities, making them a promising candidate for different biomedical applications, particularly targeted cancer therapy.