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

Abstract

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.

PLGA-Based Composites for Various Biomedical Applications

“…MNPs have been used in the clinic since the late 1990s as contrast agents (CAs) in magnetic resonance imaging (MRI) [110]. MNPs can also be used to generate heat under alternating magnetic fields (AMFs), useful for the direct ablation of tumors through magnetic hyperthermia and/or for the controlled delivery of drugs [111][112][113][114][115][116]. Additionally, some MNPs showcase a responsive behavior to changes in pH and redox states [117,118].…”

Double network hydrogels for energy/environmental applications: challenges and opportunities

“…[9][10][11] In particular, new functions, such as self-healing, conductivity, anti-freezing, adhesion, and multiple stimuli responses (e.g., pH, temperature, electric, and magnetic elds), have also been achieved. 12,13 Therefore, hydrogels have been gradually applied in exible actuators, 14 wearable sensors, 15 energy storage/ conversion, 16,17 and environmental protection. [18][19][20] However, the traditional hydrogels were generally either too so or too brittle mechanically.…”

Enhanced Mechanical Properties of Composite Hydrogels Containing Fractionated and Purified Lignin

“…4 Various approaches have been applied to alter the network structure, including manipulation of the reaction pathway, 5 crosslinker/ initiator concentration, 6 molecular weight (MW) of the host polymer, 7 and synthesis temperature. 8 For example, poly(vinyl alcohol) (PVA), a hydrogel utilized in biomedical and water purification applications, can be synthesized via thermal crosslinking, 9 chemical crosslinking, 10,11 or a combination of both. 12,13 Another common, less chemically invasive fabrication method of manipulating the network structure of PVA hydrogels is referred to as the "freeze−thaw method," which induces physical crosslinks between PVA chains through sequential cycles between temperatures of <273 and >293 K. 14 For chemically crosslinked PVA films, covalent crosslinks between chains are achieved through the use of crosslinking agents such as glutaraldehyde (GA) 7,10,15 or various acids (e.g., citric acid).…”