Magnetic nanomaterials-mediated neuromodulation

Researchers have leveraged magnetic nanomaterials (MNMs) to explore neural circuits and treat neurological diseases via an approach known as MNMs-mediated neuromodulation. Here, the magneto-responsive effects of MNMs to an external magnetic field are manipulated to activate or inhibit neuronal cell activity. In this way, MNMs can serve as a nano-mediator, by converting electromagnetic energy into heat, mechanical force/torque, and an electrical field at nanoscale. These physicochemical effects can stimulate ion channels and activate precise signaling pathways involved in neuromodulation. In this review, we outline the various ion channels and MNMs that have been applied to MNMs-mediated neuromodulation. We highlight the recent advances made in this technique and its potential applications, and then discuss the current challenges and future directions of MNMs-mediated neuromodulation. Our aim is to reveal the potential of MNMs to treat neurological diseases in the clinical setting. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease.

Design of Magnetic Nanoplatforms for Cancer Theranostics

Cancer is the top cause of death globally. Developing smart nanomedicines that are capable of diagnosis and therapy (theranostics) in one-nanoparticle systems are highly desirable for improving cancer treatment outcomes. The magnetic nanoplatforms are the ideal system for cancer theranostics, because of their diverse physiochemical properties and biological effects. In particular, a biocompatible iron oxide nanoparticle based magnetic nanoplatform can exhibit multiple magnetic-responsive behaviors under an external magnetic field and realize the integration of diagnosis (magnetic resonance imaging, ultrasonic imaging, photoacoustic imaging, etc.) and therapy (magnetic hyperthermia, photothermal therapy, controlled drug delivery and release, etc.) in vivo. Furthermore, due to considerable variation among tumors and individual patients, it is a requirement to design iron oxide nanoplatforms by the coordination of diverse functionalities for efficient and individualized theranostics. In this article, we will present an up-to-date overview on iron oxide nanoplatforms, including both iron oxide nanomaterials and those that can respond to an externally applied magnetic field, with an emphasis on their applications in cancer theranostics.

Electromagnetic Field-Programmed Magnetic Vortex Nanodelivery System for Efficacious Cancer Therapy

Effective delivery of anticancer drugs into the nucleus for pharmacological action is impeded by a series of intratumoral transport barriers. Despite the significant potential of magnetic nanovehicles in electromagnetic field (EF)-activated drug delivery, modularizing a tandem magnetoresponsive activity in a one-nanoparticle system to meet different requirements at both tissue and cellular levels remain highly challenging. Herein, a strategy is described by employing sequential EF frequencies in inducing a succession of magnetoresponses in the magnetic nanovehicles that aims to realize cascaded tissue penetration and nuclear accumulation. This nanovehicle features ferrimagnetic vortex-domain iron oxide nanorings coated with a thermo-responsive polyethylenimine copolymer (PI/FVIOs). It is shown that the programmed cascading of low frequency (Lf)-EF-induced magnetophoresis and medium frequency (Mf)-EF-stimulated magneto-thermia can steer the Doxorubicin (DOX)-PI/FVIOs to the deep tissue and subsequently trigger intracellular burst release of DOX for successful nuclear entry. By programming the order of different EF frequencies, it is demonstrated that first-stage Lf-EF and subsequent Mf-EF operation enables DOX-PI/FVIOs to effectively deliver 86.2% drug into the nucleus in vivo. This nanodelivery system empowers potent antitumoral activity in various models of intractable tumors, including DOX-resistant MCF-7 breast cancer cells, triple-negative MDA-MB-231 breast cancer cells, and BxPC-3 pancreatic cancer cells with poor permeability.