Development and Characterization of Gallic Acid‐Modified Thermoplastic Polyurethane‐Coated Magnetic Nanowires for Biomedical Applications

Abstract

Magnetic nanostructures have attracted considerable attention due to their potential applications in targeted drug delivery, cancer therapy, and biomedical imaging. In this study, multifunctional magnetic nanowire systems were developed by coating Fe3O4 nanowires with a synthesized gallic acid (GA)‐modified thermoplastic polyurethane (TPU) matrix to enhance drug loading capacity, stability, and biocompatibility. FTIR and 1H NMR analyses confirmed the presence of characteristic functional groups corresponding to gallic acid and TPU within the synthesized copolymer structure. TEM analysis of nanoparticle formulations revealed that the TPU‐GA3 formulation, containing the highest GA content, exhibited superior morphological characteristics with an average particle size of 172 ± 5.2 nm. Subsequent DLS measurements demonstrated that the particle size of TPU‐GA3 coated Fe3O4 nanowires increased with increasing Fe3O4 nanowire concentration, reaching 172 ± 1.2, 229 ± 2.3, and 576 ± 4.5 nm for 2.5Fe3O4NPs‐TPU‐GA3, 10Fe3O4NPs‐TPU‐GA3, and 30Fe3O4NPs‐TPU‐GA3, respectively. The characterization results demonstrated that the synthesized pristine Fe3O4 and TPU‐GA3‐MNWs possessed diameters of approximately 5–10 nm and lengths ranging from 50 to 200 nm. Magnetic characterization using vibrating sample magnetometer (VSM) revealed that the magnetic behavior strongly depended on Fe3O4 loading. Among the tested formulations, 10Fe3O4‐TPU‐GA3 nanowires exhibited the most balanced magnetic response with a coercivity of 35.6 Oe and a saturation magnetization of 0.0059 emu g−1. Overall, the developed polymer‐engineered magnetic nanowire platform demonstrates suitable physicochemical and magnetic properties, indicating its potential for magnetically guided drug delivery and other biomedical applications.