Design, fabrication and characterization of a magnetite-chitosan coated iron-based metal–organic framework (Fe₃O₄@chitosan/MIL-100(Fe)) for efficient curcumin delivery as a magnetic nanocarrier

Curcumin, a natural polyphenol with potent anticancer and anti-inflammatory properties, has significant limitations in biomedical applications due to its poor water solubility, rapid metabolism, and low bioavailability. To overcome these challenges, drug delivery systems such as metal-organic frameworks (MOFs) have been explored. This study developed a magnetic nanocomposite, Fe₃O₄@chitosan/MIL-100(Fe), designed to enhance curcumin delivery. The nanocomposite consists of a magnetic Fe₃O₄ core coated with biocompatible chitosan, which facilitates MOF (MIL-100(Fe)) growth, improving drug-loading capacity and targeted delivery potential. Different ratios of magnetite-coated chitosan to MOF were evaluated, with the optimal 1 : 1 ratio achieving an exceptional drug loading efficiency (DLE) of 95.36% within 24 hours and a drug loading content (DLC) of 48.81%. Brunauer-Emmett-Teller (BET) and EDX-mapping analyses confirmed that curcumin was effectively encapsulated within the nanocomposite's porous structure and uniformly adsorbed on its surface. Adsorption studies indicated that curcumin adsorption followed the Freundlich isotherm model, while kinetic analysis showed strong agreement with the intraparticle diffusion and Korsmeyer-Peppas models. Notably, the curcumin-loaded Fe₃O₄@CS/MIL-100(Fe) demonstrated greater cytotoxicity against breast cancer cells (MCF-7) than free curcumin and the unloaded nanocarrier while exhibiting lower toxicity toward normal human dermal fibroblast (HDF) cells, as confirmed by MTT assays. These findings suggest that Fe₃O₄@CS/MIL-100(Fe) offers a promising strategy to overcome curcumin's inherent limitations, paving the way for more effective targeted drug delivery systems.