Biomedical Applications of Chitosan-Coated Gallium Iron Oxide Nanoparticles GaxFe(3−x)O4 with 0 ≤ x ≤ 1 for Magnetic Hyperthermia

Nanoparticles based on gallium ferrite are explored as potential agents for magnetic fluid hyperthermia due to their magnetic performance and biocompatibility. In this study, GaxFe3−xO4 systems (0 ≤ x ≤ 1) were synthesized by co-precipitation of iron chlorides, with part of the series modified by a chitosan shell. Structural analysis confirmed single-phase formation across the studied range, while microscopy revealed irregular morphology, broad size distribution, and aggregation into mass-fractal-like assemblies. Chitosan was observed to coat groups of particles rather than single crystallites. Under an alternating magnetic field, all samples exhibited efficient heating, with specific absorption rate values generally increasing with gallium content. The composition Ga0.73Fe2.27O4 showed the highest SAR—83.4 ± 2.2 W/g at 2.8 mg/mL, 532 kHz, 15.3 kA/m, and SAR values rose with decreasing concentration. Cytotoxicity assays without magnetic activation indicated no harmful effect, while chitosan-coated nanoparticles enhanced fibroblast viability and lowered metabolic activity of HeLa cells. Higher Ga content (x = 0.66) combined with chitosan modification was identified as optimal for hyperthermia. The results demonstrate the biomedical potential of these nanoparticles, while emphasizing the need to reduce shape heterogeneity, aggregation, and sedimentation for improved performance.