Key factors influencing magnetic nanoparticle-based photothermal therapy: physicochemical properties, irradiation power, and particle concentration .

A collection of magnetic nanoparticles with average particle sizes in the range between 9 and 78 nm were prepared using several synthetic approaches that also provided different particle morphologies (spherical, octahedral and flowers). Some of these particles were also subsequently coated with different molecules in order to generate a set of materials that allowed us to evaluate the impact that the particle size, shape and coating had on the heating capacity of the nanoparticles when exposed to near infrared (NIR) laser light. Moreover, one of the prepared materials (octahedral particles of ∼32 nm coated with dextran) was used to perform an assay to study the possible use of this material in the frame of photothermal treatments to trigger cell death.

Correction: Beyond Newton's law of cooling in evaluating magnetic hyperthermia performance: a device-independent procedure.

[This corrects the article DOI: 10.1039/D4NA00383G.].

Optimization of iron oxide nanoparticles for MRI-guided magnetic hyperthermia tumor therapy: reassessing the role of shape in their magnetocaloric effect.

Superparamagnetic iron oxide nanoparticles have hogged the limelight in different fields of nanotechnology. Surprisingly, notwithstanding the prominent role played as agents in magnetic hyperthermia treatments, the effects of nanoparticle size and shape on the magnetic hyperthermia performance have not been entirely elucidated yet. Here, spherical or cubical magnetic nanoparticles synthesized by a thermal decomposition method with the same magnetic and hyperthermia properties are evaluated.

Remote Activation of Enzyme Nanohybrids for Cancer Prodrug Therapy Controlled by Magnetic Heating.

Herein, we have developed nanohybrids (nHs) to remotely activate a therapeutic enzyme for its use in Directed Enzyme Prodrug Therapy (DEPT). The coencapsulation of magnetic nanoparticles (MNPs) with horseradish peroxidase (HRP) using biomimetic silica as an entrapment matrix was optimized to obtain nanosized hybrids (∼150 nm) for remote activation of the therapeutic enzyme. HRP converts indole-3-acetic acid (3IAA) into peroxylated radicals, whereas MNPs respond to alternating magnetic fields (AMFs) becoming local hotspots.

Engineered Protein-Driven Synthesis of Tunable Iron Oxide Nanoparticles as T1 and T2 Magnetic Resonance Imaging Contrast Agents.

Iron oxide nanoparticles (IONPs) have become one of the most promising nanomaterials for biomedical applications because of their biocompatibility and physicochemical properties. This study demonstrates the use of protein engineering as a novel approach to design scaffolds for the tunable synthesis of ultrasmall IONPs. Rationally designed proteins, containing different number of metal-coordination sites, were evaluated to control the size and the physicochemical and magnetic properties of a set of protein-stabilized IONPs (Prot-IONPs).

Different coatings on magnetic nanoparticles dictate their degradation kinetics in vivo for 15 months after intravenous administration in mice.

Background: The surface coating of iron oxide magnetic nanoparticle (MNPs) drives their intracellular trafficking and degradation in endolysosomes, as well as dictating other cellular outcomes. As such, we assessed whether MNP coatings might influence their biodistribution, their accumulation in certain organs and their turnover therein, processes that must be understood in vivo to optimize the design of nanoformulations for specific therapeutic/diagnostic needs.

Results: In this study, three different MNP coatings were analyzed, each conferring the identical 12 nm iron oxide cores with different physicochemical characteristics: 3-aminopropyl-triethoxysilane (APS), dextran (DEX), and dimercaptosuccinic acid (DMSA).

Magneto-optical hyperthermia agents based on probiotic bacteria loaded with magnetic and gold nanoparticles.

Probiotic bacteria were used as carriers of metallic nanoparticles to develop innovative oral agents for hyperthermia cancer therapy. Two synthetic strategies were used to produce the different therapeutic agents. First, the probiotic bacterium was simultaneously loaded with magnetic (MNPs) and gold nanoparticles (AuNPs) of different morphologies to produce AuNP + MNP-bacteria systems with both types of nanoparticles arranged in the same layer of bacterial exopolysaccharides (EPS).

Iron-Gold Nanoflowers: A Promising Tool for Multimodal Imaging and Hyperthermia Therapy.

The development of nanoplatforms prepared to perform both multimodal imaging and combined therapies in a single entity is a fast-growing field. These systems are able to improve diagnostic accuracy and therapy success. Multicomponent Nanoparticles (MCNPs), composed of iron oxide and gold, offer new opportunities for Magnetic Resonance Imaging (MRI) and Computed Tomography (CT) diagnosis, as well as combined therapies based on Magnetic Hyperthermia (MH) and Photothermal Therapy (PT).

Ultrasmall Manganese Ferrites for In Vivo Catalase Mimicking Activity and Multimodal Bioimaging.

Manganese ferrite nanoparticles display interesting features in bioimaging and catalytic therapies. They have been recently used in theranostics as contrast agents in magnetic resonance imaging (MRI), and as catalase-mimicking nanozymes for hypoxia alleviation. These promising applications encourage the development of novel synthetic procedures to enhance the bioimaging and catalytic properties of these nanomaterials simultaneously.

Iron Speciation in Animal Tissues Using AC Magnetic Susceptibility Measurements: Quantification of Magnetic Nanoparticles, Ferritin, and Other Iron-Containing Species.

The simultaneous detection and quantification of several iron-containing species in biological matrices is a challenging issue. Especially in the frame of studies using magnetic nanoparticles for biomedical applications, no gold-standard technique has been described yet and combinations of different techniques are generally used. In this work, AC magnetic susceptibility measurements are used to analyze different organs from an animal model that received a single intratumor administration of magnetic nanoparticles.

Characterization of two Cuban colonies of Rhipicephalus microplus ticks.

Rhipicephalus microplus (Canestrini, 1888) is one of the species with medical and economic relevance that has been reported in the list of Cuban tick species. Some morphological characterizations about the R. microplus species in Cuba have been published; however, molecular studies are lacking.

FeO-Au Core-Shell Nanoparticles as a Multimodal Platform for In Vivo Imaging and Focused Photothermal Therapy.

In this study, we report the synthesis of gold-coated iron oxide nanoparticles capped with polyvinylpyrrolidone (Fe@Au NPs). The as-synthesized nanoparticles (NPs) exhibited good stability in aqueous media and excellent features as contrast agents (CA) for both magnetic resonance imaging (MRI) and X-ray computed tomography (CT). Additionally, due to the presence of the local surface plasmon resonances of gold, the NPs showed exploitable "light-to-heat" conversion ability in the near-infrared (NIR) region, a key attribute for effective photothermal therapies (PTT).

Dysprosium and Holmium Vanadate Nanoprobes as High-Performance Contrast Agents for High-Field Magnetic Resonance and Computed Tomography Imaging.

We describe a wet chemical method for the synthesis of uniform and well-dispersed dysprosium vanadate (DyVO) and holmium vanadate (HoVO) nanoparticles with an almost spherical shape and a mean size of ∼60 nm and their functionalization with poly(acrylic acid). The transverse magnetic relaxivity of both systems at 9.4 T is analyzed on the basis of magnetic susceptibility and magnetization measurements in order to evaluate their potential for application as high-field MRI contrast agents.

The Intracellular Number of Magnetic Nanoparticles Modulates the Apoptotic Death Pathway after Magnetic Hyperthermia Treatment.

Magnetic hyperthermia is a cancer treatment based on the exposure of magnetic nanoparticles to an alternating magnetic field in order to generate local heat. In this work, 3D cell culture models were prepared to observe the effect that a different number of internalized particles had on the mechanisms of cell death triggered upon the magnetic hyperthermia treatment. Macrophages were selected by their high capacity to uptake nanoparticles.