Speaker
Description
Thrombotic disorders remain a major cause of morbidity and mortality worldwide, while conventional antithrombotic therapy is limited by systemic drug exposure and associated bleeding risks. Magnetic drug delivery systems offer a strategy for increasing the local concentration of therapeutic agents at a thrombotic site through external magnetic guidance. In this work, Fe3O4@SiO2-based nanocarriers were investigated as a platform for localized delivery of the anticoagulant apixaban and for their interaction with the fibrin network of blood clots.
Magnetic silica nanoparticles were prepared using Fe3O4 cores coated with silica and characterized with respect to morphology, porous structure and magnetic properties. Electron microscopy confirmed the core–shell architecture, while nitrogen adsorption measurements demonstrated a porous silica structure suitable for drug incorporation. Magnetic measurements showed superparamagnetic behaviour at room temperature, enabling manipulation of the particles by an external magnetic field.
The interaction of the nanocarriers with blood clots was subsequently investigated under dynamic conditions using an experimental circulation model. Apixaban-loaded Fe3O4@SiO2 nanoparticles were circulated in the presence of a blood clot and an external magnetic field. Macroscopic observations demonstrated magnetic accumulation of the nanoparticles in the vicinity of the clot. SEM examination revealed nanoparticle aggregates associated with the clot surface and partially entrapped within the fibrin network.
These results demonstrate the feasibility of magnetic localization of silica-based nanocarriers under dynamic conditions but also reveal an important unresolved question: whether magnetic targeting primarily promotes surface retention or enables penetration of the nanocarriers into the three-dimensional fibrin network. Conventional surface imaging cannot fully resolve their spatial distribution within the clot. Advanced X-ray scattering and imaging approaches could therefore provide complementary information on nanocarrier localization, penetration depth and nanoparticle-induced structural changes in the fibrin network. Such insight may contribute to the rational development of magnetically targeted systems for localized antithrombotic drug delivery.
