Xanthan-Fe3O4 Nanoparticle Composite Hydrogels for Non-Invasive Magnetic Resonance Imaging and Magnetically Assisted Drug Delivery

Implantable long-acting delivery systems able to minimize off-target side effects and locally provide non-invasive imaging reporting are of utmost importance to offer a precise treatment of internal diseases and accurate assessment of disease progression, such as in local infections and tumor relapse following surgery, among other diseases. Here, a biocompatible xanthan gum/Fe3O4-based drug-loaded magnetic nanoparticle composite hydrogel with suitable rheological properties and theranostic performance was designed. The ultra-high efficacy of the chemically modified polysaccharide matrix to simultaneously encapsulate hydrophilic drugs and magnetic iron oxide nanoparticles rendered the final hydrogel magnetically responsive to enable thermally induced controlled drug delivery by magnetic hyperthermia as well as non-invasive monitoring by magnetic resonance imaging (MRI). In addition to an enhanced activity of the drug-loaded hydrogel compared to the free drug, results showed that the application of an alternating magnetic field efficiently stimulated a 3-fold faster release of the encapsulated drug compared to passive conditions, whereas a concentration-dependent shortening of the water protons' relaxation time at a clinical field of 3 T confirmed this magnetic hydrogel as a T-2-MRI contrast enhancer. Altogether, these properties open a novel dimension for the application of these versatile magnetic nanoparticle composite hydrogels, from traditional topical uses to more internal surgery interventions in dentistry, oncology, or wound healing of critical skin damage and infections.

Automated summary

This study introduces a biocompatible hydrogel with magnetic nanoparticles, allowing controlled drug release and non-invasive monitoring, which is crucial for precise treatment of internal diseases.