The applications of alginate-functionalized magnetite nanoparticles (Fe3O4@Alg NPs) for drug delivery have
been limited reported. In this study, Fe3O4@Alg NPs was successfully formulated using the co-precipitation
method for the adsorption and delivery of curcumin in both oral and injectable routes. The Fe3O4@Alg NPs
were synthesized under optimized conditions with a high saturation magnetization value and negligible remnant
magnetization. Curcumin was efficiently integrated into the system through adsorption, achieving a drug
encapsulation efficiency of 71% over 12 h, an average NPs size of 100–200 nm, a 1.2-time increase in the
curcumin solubility, with insignificant hemolytic effects at concentrations of up to 20 mg mL- 1. The adsorption
isotherms and kinetic studies showed that the drug adsorption process was rapid, with low slope coefficient, high
adsorption capacity of 5.981 mg g- 1, and monolayer of curcumin physically adsorbed onto the NPs surfaces.
Moreover, the Fe3O4@Alg NPs could protect curcumin from the acidic gastric environment and sustainably
release it under simulated physiological (pH 7.4) and intestinal conditions (pH 6.8), with the release percentages
of 93.48% and ~100%, respectively. In summary, this study demonstrated the significant potential of
Fe3O4@Alg NPs in enhancing the bioavailability of curcumin. These nanoparticles can be further explored as a
promising distribution system for both oral and injectable administration.