A bio-inspired magnetic natural hydrogel containing gelatin and alginate as a drug delivery system for cancer chemotherapy.

This study aimed to design and development of a magnetic natural hydrogel based on alginate (Alg), gelatin (Gel), and Fe3O4 magnetic nanoparticles (MNPs) as an efficient and "smart" drug delivery system (DDS) for cancer therapy. First, Alg was partially oxidized (OAlg), and then the Alg-Gel chemical hydrogel was synthesized through "Shift-Base" condensation reaction. Afterward, Fe3O4 NPs were incorporated into the hydrogel through in situ chemical co-precipitation approach. The scanning electron microscopy (SEM) image exhibited that the fabricated Alg-Gel hydrogel has porous microstructure without microphase separation. Transmission electron microscopy (TEM) revealed the well-defined formation of Fe3O4 NPs throughout the Alg-Gel hydrogel with spherical shapes in the size range of 25 ± 10 nm. Saturation magnetization (δs) value of the Alg-Gel/Fe3O4 was obtained to be 31 emu g-1 that represent proper magnetic property for "smart" drug delivery purposes. The obtained Alg-Gel/Fe3O4 was loaded with doxorubicin hydrochloride (Dox), and its drug loading and encapsulation efficiencies as well as its anticancer activity was investigated against Hela cells. The formulated Alg-Gel/Fe3O4-Dox exhibited pH-dependent drug release behavior due to presence of carboxylic acid groups in the DDS. According to the results, the Alg-Gel/Fe3O4 magnetic hydrogel can be considered as an efficient and "smart" DDS for cancer therapy and diagnosis.