Open Access
Fe3O4-SiO2 mesoporous core/shell nanoparticles for magnetic field-induced ibuprofen-controlled release
(American Chemical Society, 2022-12-23) García Rodríguez, Lucía; Garayo Urabayen, Eneko; López Ortega, Alberto; Galarreta Rodríguez, Itziar; Cervera Gabalda, Laura María; Cruz Quesada, Guillermo; Cornejo Ibergallartu, Alfonso; Garrido Segovia, Julián José; Gómez Polo, Cristina; Pérez de Landazábal Berganzo, José Ignacio; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PJUPNA2020; Gobierno de Navarra / Nafarroako Gobernua
Hybrid magnetic nanoparticles made up of an iron oxide, Fe3O4, core and a mesoporous SiO2 shell with high magnetization and a large surface area were proposed as an efficient drug delivery platform. The core/shell structure was synthesized by two seed-mediated growth steps combining solvothermal and sol—gel approaches and using organic molecules as a porous scaffolding template. The system presents a mean particle diameter of 30(5) nm (9 nm magnetic core diameter and 10 nm silica shell thickness) with superparamagnetic behavior, saturation magnetization of 32 emu/g, and a significant AC magnetic-field-induced heating response (SAR = 63 W/gFe3O4, measured at an amplitude of 400 Oe and a frequency of 307 kHz). Using ibuprofen as a model drug, the specific surface area (231 m2/g) of the porous structure exhibits a high molecule loading capacity (10 wt %), and controlled drug release efficiency (67%) can be achieved using the external AC magnetic field for short time periods (5 min), showing faster and higher drug desorption compared to that of similar stimulus-responsive iron oxide-based nanocarriers. In addition, it is demonstrated that the magnetic field-induced drug release shows higher efficiency compared to that of the sustained release at fixed temperatures (47 and 53% for 37 and 42 °C, respectively), considering that the maximum temperature reached during the exposure to the magnetic field is well below (31 °C). Therefore, it can be hypothesized that short periods of exposure to the oscillating field induce much greater heating within the nanoparticles than in the external solution.
Open Access
Nanoscale engineering of cobalt-gallium co-doped ferrites: a strategy to enhance high-frequency theranostic magnetic materials
(American Chemical Society, 2025-07-01) Galarreta Rodríguez, Itziar; Liguori, Deborah; Garayo Urabayen, Eneko; Muzzi, Beatrice; Cervera Gabalda, Laura María; Rubio Zuazo, Juan; Gomide, Guilherme; Depeyrot, Jérõm; López Ortega, Alberto; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Universidad Publica de Navarra / Nafarroako Unibertsitate Publikoa
The nanoscale engineering of doped iron oxide magnetic nanoparticles has attracted significant interest in recent years for high-frequency theragnostic applications, where simultaneous diagnosis and therapy are required. In particular, their ability to generate localized heating under alternating magnetic fields makes them ideal candidates for magnetic hyperthermia, a noninvasive cancer treatment technique. However, understanding the complex interplay between multiple dopant cations and their impact on dynamic magnetic behavior remains a significant challenge. In this work, we present a comprehensive study on how two differently marked cations (Co2+ and Ga3+) can modify both the magnetic properties of these nanoparticles and their efficiency in heat generation under alternating magnetic fields. To this end, a series of nanoparticles with the formula CoxGa0.15Fe2.85-xO4 (0 < x < 0.3) was prepared via thermal decomposition, enabling the production of monodisperse nanocrystals with high crystallinity and precise stoichiometric control. Their exhaustive structural and magnetic characterization confirmed site-selective incorporation of Ga3+ into tetrahedral sites and Co2+ into octahedral sites. Increasing the cobalt content within the gallium-doped framework leads to enhanced magnetocrystalline anisotropy and higher saturation magnetization, both crucial parameters for efficient heat dissipation in magnetic hyperthermia. The study further demonstrates that the dynamic magnetic response of these nanostructures is strongly influenced by the interplay between doping composition, anisotropy, and the amplitude of the applied magnetic field. These findings highlight the effectiveness of nanoscale codoping strategies in fine-tuning magnetic behavior and optimizing the performance of spinel ferrite nanoparticles for advanced biomedical and technological applications, particularly high-frequency magnetic hyperthermia.
Open Access
Magnetic binary encoding system based on 3D printing and GMI detection prototype
(Elsevier, 2022) Beato López, Juan Jesús; Algueta-Miguel, Jose M.; Galarreta Rodríguez, Itziar; López Ortega, Alberto; Garayo Urabayen, Eneko; Gómez Polo, Cristina; Aresti Bartolomé, Maite; Soria Picón, Eneko; Pérez de Landazábal Berganzo, José Ignacio; Ciencias; Zientziak; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako Gobernua; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In this work, the feasibility of a magnetic binary encoding system using 3D printing technology is analyzed. The study has a double interest, that is, the possibility of printing a 3D piece that contains the codified information and the development of a system for its decoding. For this purpose, magnetic nanoparticles (magnetite Fe3O4) were embedded in a polymeric matrix of Polylactic Acid (PLA) and Poly-ε-caprolactone (PCL). Similar to a conventional barcode, a rectangular piece with an alternating pattern of strips with absence (only polymer) and a 5 wt% of embedded magnetic nanoparticles was 3D printed employing the Fused Deposition Modelling tech- nique (FDM). The information was decoded by means of a Giant Magnetoimpedance (GMI) sensor-based pro- totype, by scanning the surface of the piece and measuring the changes in the magnetic field. As sensor nucleus, an amorphous soft magnetic wire of nominal composition (Co0.94 Fe0.06)72.5 Si12.5 B15 was employed. The decoding prototype incorporates a homemade electronic sensor interface that permits, at the time, the GMI sensor excitation and the subsequent signal conditioning to optimize its response. The output signal enables the detection of the magnetite nanoparticles and the magnetic decoding of the encoded information (“1” and “0”, presence or absence of the magnetic nanoparticles, respectively).
Open Access
Magnetically activated 3D printable polylactic acid/polycaprolactone/magnetite composites for magnetic induction heating generation
(Springer, 2023) Galarreta Rodríguez, Itziar; López Ortega, Alberto; Garayo Urabayen, Eneko; Beato López, Juan Jesús; La Roca, Paulo Matías; Sánchez-Alarcos Gómez, Vicente; Recarte Callado, Vicente; Gómez Polo, Cristina; Pérez de Landazábal Berganzo, José Ignacio; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Additive manufacturing technology has attracted the attention of industrial and technological sectors due to the versatility of the design and the easy manufacture of structural and functional elements based on composite materials. The embedding of magnetic nanoparticles in the polymeric matrix enables the development of an easy manufacturing process of low-cost magnetically active novel polymeric composites. In this work, we report a series of magnetic composites prepared by solution casting method combining 5 to 60 wt.% of 140 ± 50 nm commercial Fe3O4 nanoparticles, with a semi-crystalline, biocompatible, and biodegradable polymeric blend made of polylactic acid (PLA) and polycaprolactone (PCL). The composites were extruded, obtaining 1.5 ± 0.2 mm diameter continuous and flexible filaments for fused deposition modelling 3D printing. The chemical, magnetic, and calorimetric properties of the obtained filaments were investigated by differential scanning calorimetry, thermogravimetric analysis, magnetometry, and scanning electron microscopy. Furthermore, taking advantage of the magnetic character of the filaments, their capability to generate heat under the application of low-frequency alternating magnetic fields (magnetic induction heating) was analyzed. The obtained results expose the versatility of these easy manufacturing and low-cost filaments, where selecting a desired composition, the heating capacity can be properly adjusted for those applications where magnetic induction plays a key role (i.e., magnetic hyperthermia, drug release, heterogeneous catalysis, water electrolysis, gas capture, or materials synthesis).
Open Access
Non-linear GMI decoding in 3D printed magnetic encoded systems
(Elsevier, 2023) Beato López, Juan Jesús; Algueta-Miguel, Jose M.; Galarreta Rodríguez, Itziar; Garayo Urabayen, Eneko; López Ortega, Alberto; Gómez Polo, Cristina; Pérez de Landazábal Berganzo, José Ignacio; Ciencias; Ingeniería Eléctrica, Electrónica y de Comunicación; Institute for Advanced Materials and Mathematics - INAMAT2; Institute of Smart Cities - ISC; Zientziak; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The nonlinear giant magnetoimpedance (GMI) effect was explored as a highly sensitive sensing technology in 3D-printed magnetic encoded systems. Magnetic nanoparticles with low (magnetite, Fe3O4) and high (Co ferrite, Co0.7Fe2.3O4) magnetic remanence were embedded (10 wt%) in a polymeric matrix of Polylactic Acid (PLA) and Poly-ε-caprolactone (PCL) and extruded in magnetic filaments to be 3D printed by the Fused Deposition Modelling technique (FDM). Two different geometries were constructed namely, individual magnetic strips and fixed barcoded pieces. The stray magnetic fields generated by the magnetic nanoparticles were detected through the non-linear (second harmonic) GMI voltage using a soft magnetic CoFeSiB wire as the nucleus sensor. The decoding response was analyzed as a function of the magnetization remanence of the nanoparticles, the distance between the individual magnetic strips, and the position (height) of the GMI decoding sensor. It has been shown that modification of the net magnetization direction of each individual fixed strip within the barcode geometry is possible through the application of local external magnetic fields. This possibility improves the versatility of the 3D binary encoding system by adding an additional state (0 without nanoparticles, 1 or −1 depending on the relative orientation of the net magnetization along the strips) during the codifying procedure.