Speaker
Description
Magnetic mesoporous silica nanoparticles (MSNs) represent a sophisticated category of nanomaterials combining magnetic responsiveness with the versatile drug delivery capabilities of mesoporous silica. Their distinctive structure, characterized by a mesoporous silica shell encapsulating superparamagnetic iron oxide cores, enables efficient drug loading, controlled therapeutic release, and precise targeting through external magnetic fields [1]. This research specifically explores the synthesis and application of magnetic MSNs for targeted delivery of antithrombotic drugs, providing an innovative approach for treating thrombotic conditions by delivering medications directly to blood clots with improved precision. Particularly, their magnetic guidance could significantly enhance rapid and precise localization of blood clots, allowing reduced drug dosages and minimizing systemic side effects.
The nanoparticles were synthesized by a coprecipitation method, followed by hydrolysis of tetraethyl orthosilicate (TEOS) in a basic environment to form a SiO$_2$ layer surrounding the iron oxide (Fe$_3$O$_4$) magnetic core. Subsequently, an additional porous silica layer was introduced using cetyltrimethylammonium bromide (CTAB) and polyethylene glycol (PEG) surfactants as pore-generating agents. Nanoparticle characterization involved nitrogen adsorption/desorption measurements, thermal analysis, infrared spectroscopy, X-ray diffraction, transmission and scanning electron microscopy (TEM and SEM). Results indicated that nanoparticles synthesized with CTAB and PEG demonstrated optimal properties for drug delivery applications due to their pore size distributions ($3.2–4$ nm and $2–4$ nm, respectively) and high specific surface areas ($480$ m$^2$/g and $320$ m$^2$/g, respectively), significantly enhancing drug encapsulation capacity.
A detailed analysis of the magnetic properties was performed using SQUID magnetometry, including measurements of magnetic hysteresis loops (magnetization curves, $M$(H)) and temperature-dependent magnetization curves in the zero-field-cooled and field-cooled (ZFC/FC) regimes. These studies confirmed the superparamagnetic behaviour and responsiveness to external magnetic fields, highlighting their suitability for precise magnetic targeting applications. The magnetic properties are crucial to achieving selective nanoparticle accumulation at thrombotic sites through external magnetic guidance, as well as optimizing nanoparticle penetration and diffusion into clot tissue by adjusting magnetic field intensity.
Acknowledgements
Funded by the EU NextGenerationEU through the Recovery and Resilience Plan for Slovakia under the project No. 09I03-03-V04-00722.
References
[1] C. Comanescu, “Magnetic Nanoparticles: Current Advances in Nanomedicine, Drug Delivery and MRI,” Chemistry, vol. 4, no. 3. MDPI AG, pp. 872–930, Aug. 27, 2022. https://doi.org/10.3390/chemistry4030063
