Enhanced biomedical performance of magnetic Fe3O4@chitosan nanocomposites: A comparative study of synthesis methods for hyperthermia and chemotherapy applications

This study investigates the synthesis of magnetite/chitosan nanocomposites (Fe 3 O 4 @CS) using in-situ and ex-situ methods. The nanocomposites were characterized by FTIR, XRD, TEM, and VSM analyses. Their potential in nanomedicine was assessed through chemosensitivity tests on Ehrlich ascites carcinoma (EAC) and hyperthermic performance under an alternating magnetic field. The particle size of Fe 3 O 4 nanoparticles was 10-20 nm and 20-40 nm for in-situ and ex-situ prepared samples as revealed by TEM images. FTIR indicated strong interactions between magnetite and chitosan, while XRD revealed a more uniform crystalline structure of Fe 3 O 4 nanoparticles in ex-situ prepared samples. VSM analysis showed higher magnetization saturation for the ex-situ samples, with magnetization decreasing as chitosan content increased. In vitro assays demonstrated that both synthesis routes influenced the cytotoxicity of the nanocomposites against EAC cells, with in-situ samples showing greater early-stage cytotoxicity causing 40% reduction in cell viability at 10 μg/mL. Under an alternating magnetic field, Fe 3 O 4 @CS nanocomposites reached therapeutic hyperthermia temperatures, with in-situ samples achieving 40.1–41.4°C and ex-situ samples reaching 41–43°C. These results highlight the importance of synthesis method and chitosan content in tailoring Fe 3 O 4 @CS nanocomposites for efficient and targeted hyperthermia-based cancer treatment.