89. Magnetically propelled chained nanocomposites for biologically relevant media exploration

Miguel A. Ramos-Docampo, Pablo Hurtado, Ana B. Dávila-Ibáñez, Roberto Piñeiro, Mónica L. Fanarraga, Verónica Salgueiriño

Journal of Colloid and Interface Science (2023), 629, 287-296 (DOI: 10.1016/j.jcis.2022.08.154).

Elongated nanosstructures to be remotely and magnetically propelled in biologically relevant media, have gained attention as offering themselves as effective tools or carriers in theragnostics applications. However, the magnetic actuation associated remains challenging due to the lack of mechanical information in the media of interest, taking into account biophysical or biomedical purposes. In this study, we detail the magnetic actuation of magnetically propelled chained nanocomposites considering their dynamics, in which their velocity can be modulated in terms of the viscosity of the medium considered, given a magnetic field gradient. 

 54 JCIS

88. Synergistic Interaction of Clusters of Iron Oxide Nanoparticles and Reduced Graphene Oxide for High Supercapacitor Performance

Amir Elsaidy, Julia N. Majcherkiewicz, Begoña Puértolas, Verónica Salgueiriño, Xosé Ramón Nóvoa, Miguel A. Correa-Duarte

Nanomaterials (2022), 12, 2695 (DOI: 10.3390/nano12152695).

Supercapacitors have been recognized as one of the more promising energy storage devices with great potential use in portable electronics and hybrid vehicles. A composite made of clusters of iron oxide nanoparticles and reduced graphene oxide has been developed through a simple one-step solvothermal synthesis method for a high-performance supercapacitor electrode. Electrochemical assessment via cyclic voltammetry, galvanostatic charge-discharge experiments, and electrochemical impedance spectroscopy revealed that the iron oxide-reduced graphene oxide nanocomposites showed much higher specicfic capacitance than the individual components.

53 Nanomaterials 

87. Tuning the Drug Multimodal Release through a Co-Assembly Strategy based on Magnetic Gels

Sergio R. S. Veloso, Ecem Tiryaki, Carlos Spuch, Loic Hilliou, C. O. Amorim, V. S. Amaral, Paulo J. G. Coutinho, Paula M. T. Ferreira, Verónica Salgueiriño, Miguel A. Correa-Duarte and Elisabete M. S. Castanheira

Nanoscale (2022), in press (DOI: 10.1039/d1nr08158f).

Self-assembled short peptide-based gels as drug delivery systems require the implementation of a stimulus to modulate the release of doxorubicin, through the interplay of (di)phenylalanine-coated magnetic nanoparticles, PEGylated liposomes and the doxorubicin co-assembly.

The integration of the liposomes as doxorubicin storage units and of magnetic nanoparticles within the gel matrix enable the tuneability of both passive and active doxorubicin release through a thermal, low-frequency alternating magnetic field-based trigger.

 52 Nanoscale

86. Tuning the Thermal Properties of Aqueous Nanofluids by Taking Advantage of Size-customized Clusters of Iron Oxide Nanoparticles

Amir Elsaidy, Javier P. Vallejo, Verónica Salgueiriño and Luis Lugo

Journal of Molecular Liquids (2021), 344, 117727 (DOI: 10.1016/j.molliq.2021.117727).

The thermal conductivity of aqueous nanofluids containing clusters of iron oxide (Fe3O4 / γ-Fe2O3) nanoparticles has been investigated experimentally, with the aim of assessing the role of a controlled aggregation of nanoparticles in these final nanofluids. The clusters of nanoparticles were synthesized by a solvothermal method and fully characterized by TEM, XRD and Raman spectroscopy. The rheological behavior of the optimal nanofluids was studied by rotational rheometry, revealing enhancements in the thermal conductivity, temperature and cluster size dependent.

51 JMolLiq 

85. Manganese Ferrite Nanoparticles Encapsulated into Vitamin E/Sphingomyelin Nanoemulsions as Contrast Agents for High-Sensitive Magnetic Resonance Imaging

Sandra Díez-Villares, Miguel A. Ramos-Docampo, Andrés da Silva-Candal, Pablo Hervella, Abi J. Vázquez-Ríos, Ana B. Dávila-Ibáñez, Rafael López-López, Ramón Iglesias-Rey, Verónica Salgueiriño and María de la Fuente

Advanced Healthcare Materials (2021), 2101019 (DOI: 10.1002/adhm.202101019).

Magnetic resonance imaging (MRI) is one of the most powerful non-invasive imaging modalities used in clinics due to its great spatial resolution and excellent soft-tissue contrast, though still less sensitive than other techniques such as the nuclear imaging modalities. This lack of sensitivity can be considerably improved with the use of contrast agents based on nanomaterials. In recent years, researchers have focused on the development of magnetic nanoparticles, given their role as enhancers of the contrast signal based on the magnetic resonance. Manganese ferrite nanoparticles stand out, given their high magnetic susceptibility and magnetic soft nature. Herein, 10 nm MnFe2O4 nanoparticles, functionalized with the natural antioxidant vitamin E (VitE-MFO) are encapsulated into simple, biodegradable and non-toxic nanoemulsions (NEs), by a reproducible one-step method obtaining stable 150 nm-sized magnetic nanoemulsions (VitE-MFO-NEs). After encapsulation, the superparamagnetic properties of VitE-MFO are maintained and MR imaging studies reveal an extremely high transverse relaxivity for VitE-MFO-NEs (652.9 mM−1s−1), 2-fold higher than VitE-MFO value. Moreover, VitE-MFO-NEs show great in vivo biocompatibility and good signal at a low dose by in vivo and ex vivo MRI, which indicates their great potential for biomedical imaging enhancing the negative MR contrast and significantly improving the sensitivity of MRI.

50 2021 AHM