Curcumin-loaded PEGylated Magnetic Iron Oxide Nanoparticles: a Biogenic Platform for Targeted and Controlled Drug Release.

The development of environmentally sustainable and targeted nanocarriers is crucial for improving the therapeutic efficacy of anticancer agents while reducing systemic toxicity. Here we successfully synthesized curcumin (CUR) loaded polyethylene glycol (PEG) functionalized magnetic iron oxide nanoparticles (Fe3O4@PEG-CUR-NPs) by a green biogenic approach using Hibiscus rosa-sinensis flower extract and evaluated as a multifunctional platform for controlled drug delivery and cancer therapy. UV-Vis, FTIR, PXRD, SEM, TEM, DLS, TGA and VSM characterizations have been performed comprehensively to confirm the successful fabrication of crystalline, spherical nanoparticles with average size of 10-15 nm, excellent colloidal stability (zeta potential - 31.5 mV) and retained magnetic responsiveness with saturation magnetization of 28.30 emu/g. The nanocarrier showed significant pH-responsive drug release, with 90.55% cumulative CUR release under acidic conditions (pH 4.5) compared to 44.5% at physiological pH (7.4), indicating its possibility for tumor-targeted delivery. Release kinetic studies revealed that the drug release was mainly diffusion-controlled and followed a non-Fickian transport mechanism. Besides, Fe3O4@PEG-CUR-NPs showed good anti-inflammatory effect with IC50 value of 25.10 μg/mL, which was significantly better than diclofenac (IC50 = 82.20 μg/mL). In vitro cytotoxicity assays showed potent and dose dependent anticancer activity against A549, MDA-MB-231 and MCF-7 cell lines with IC50 values of 50.2, 10.5 and 6.7 μg/mL respectively, indicating an increased susceptibility of breast cancer cells. The synergistic combination of green synthesis, magnetic targeting capability, pH-triggered drug release, and superior anticancer efficacy highlights Fe3O4@PEG-CUR-NPs as a promising nanotherapeutic platform for precision cancer treatment and advanced biomedical applications.