Study of Galfenol direct cytotoxicity and remote microactuation in cells

Nanomedicine, 2012

In this review, we discuss the prospective medical application of magnetic carriers microfabricated by top-down techniques. Physical methods allow the fabrication of a variety of magnetic structures with tightly controlled magnetic properties and geometry, which makes them very attractive for a cost-efficient mass-production in the fast growing field of nanomedicine. Stand-alone fabricated particles along with integrated devices combining lithographically defined magnetic structures and synthesized magnetic tags will be considered. Applications of microfabricated multifunctional magnetic structures for future medicinal purposes range from ultrasensitive in vitro diagnostic bioassays, DNA sequencing and microfluidic cell sorting to magnetomechanical actuation, cargo delivery, contrast enhancement and heating therapy.

Advanced Materials, 2013

Carolina Digital Repository (University of North Carolina at Chapel Hill), 2015

The paper describes the concept of magneto-mechanical actuation of single-domain magnetic nanoparticles (MNPs) in super-low and low frequency alternating magnetic fields (AMFs) and its possible use for remote control of nanomedicines and drug delivery systems. The applications of this approach for remote actuation of drug release as well as effects on biomacromolecules, biomembranes, subcellular structures and cells are discussed in comparison to conventional strategies employing magnetic hyperthermia in a radio frequency (RF) AMF. Several quantitative models describing interaction of functionalized MNPs with single macromolecules, lipid membranes, and proteins (e.g. cell membrane receptors, ion channels) are presented. The optimal characteristics of the MNPs and an AMF for effective magneto-mechanical actuation of single molecule responses in biological and bio-inspired systems are discussed. Altogether, the described studies and phenomena offer opportunities for the development of novel therapeutics both alone and in combination with magnetic hyperthermia.

Applied Sciences

This review focuses on novel applications based on multifunctional materials to actuate biological processes. The first section of the work revisits the current knowledge on mechanically dependent biological processes across several scales from subcellular and cellular level to the cell-collective scale (continuum approaches). This analysis presents a wide variety of mechanically dependent biological processes on nervous system behaviour; bone development and healing; collective cell migration. In the second section, this review presents recent advances in smart materials suitable for use as cell substrates or scaffolds, with a special focus on magneto-active polymers (MAPs). Throughout the manuscript, both experimental and computational methodologies applied to the different treated topics are reviewed. Finally, the use of smart polymeric materials in bioengineering applications is discussed.

Advanced materials & technologies, 2018

Magnetic/superparamagnetic nanoparticles (MNPs) controlled by an external magnetic field (MF) have a great potential for various biomedical applications. The MNPs make it possible to provide selective nanomechanical impact at the level of individual molecules of the intended type by means of their magnetomechanical actuation in the low-frequency MF. However, the MNPs introduced into the bloodstream can accumulate in many organs, creating the hazard of unexpected side effects that may occur when activating alternating MF is turned on. In this paper, we propose a new physical method and technology of localization of the MNP impact on the biochemical system, by creating a static gradient localizing MF with a field free point near the center of the magnetic system. Under these conditions, the activating alternating MF stimulates only those MNPs that are in the vicinity of the field free point. Far from it, where the localizing MF is higher than the stimulating alternating MF, the MNPs are "frozen" in static field and are not affected by the weaker activating alternating MF. The shape and size of the impact localization region are studied depending on the characteristics of the localizing and activating MF.

Journal of Physics D: Applied Physics, 2016

In recent years there have been tremendous advances in the versatility of magnetic shuttle technology using nano/micro-scale magnets for digital magnetophoresis. While the technology has been used for a wide variety of single-cell manipulation tasks such as selection, capture, transport, encapsulation, transfection, or lysing of magnetically labeled and unlabeled cells, it has also expanded to include parallel actuation and study of multiple bio-entities. The use of nano/micro-patterned magnetic structures that enable remote control of the applied forces has greatly facilitated integration of the technology with micro uidics, thereby fostering applications in the biomedical arena. The basic design and fabrication of various scaled magnets for remote manipulation of individual and multiple beads/cells, and their associated energies and forces that underlie the broad functionalities of this approach, are presented. One of the most useful features enabled by such advanced integrated engineering is the capacity to remotely tune the magnetic eld gradient and energy landscape, permitting such multipurpose shuttles to be implemented within lab-on-chip platforms for a wide range of applications at the intersection of cellular biology and biotechnology.

Biotechnology Advances, 2020

Surface active magnetic nanoparticles especially superparamagnetic iron oxides are already occupying a major domain in medical therapeutics. Arresting of these magnetic nanoparticles into polymer hydrogel is a spatial assembly of nanoparticles that serves the precise delivery of drug molecules. Magnetic hydrogels are very less cultured area still in the biomedical field. This review embraces how the external magnetic field (either static or oscillating) affects the payload release from the hydrogel matrix and their magneto-regulative deformation. Besides these, we also discussed how the ferrosponge and biphasic ferrogel based scaffold type systems impact over the release kinetics and tunability of drug release behaviours.

Nanomaterials

The review discusses the theoretical, experimental and toxicological aspects of the prospective biomedical application of functionalized magnetic nanoparticles (MNPs) activated by a low frequency non-heating alternating magnetic field (AMF). In this approach, known as nano-magnetomechanical activation (NMMA), the MNPs are used as mediators that localize and apply force to such target biomolecular structures as enzyme molecules, transport vesicles, cell organelles, etc., without significant heating. It is shown that NMMA can become a biophysical platform for a family of therapy methods including the addressed delivery and controlled release of therapeutic agents from transport nanomodules, as well as selective molecular nanoscale localized drugless nanomechanical impacts. It is characterized by low system biochemical and electromagnetic toxicity. A technique of 3D scanning of the NMMA region with the size of several mm to several cm over object internals has been described.

InTech eBooks, 2016

The use of wireless magnetic control to transport and deliver chemotherapeutic agents selectively to tumor cells has become a promising strategy to mitigate the negative side effects associated with conventional treatment. It is necessary to manipulate and penetrate biological cells using magnetic agent to achieve this targeted drug delivery. Contact and non-contact micromanipulation of cell mockups and biological cells (human astrocytoma cell line U-373 MG and human breast adenocarcinoma cell line MCF-7) is achieved using magnetic agents (paramagnetic microparticles and iron oxide nanoparticles). The contact manipulation is accomplished under the influence of the controlled magnetic field gradients exerted on the magnetic agent, whereas the non-contact manipulation is done under the influence of the magnetic field and pressure gradients exerted on the agent and biological cells, respectively. We develop a magnetic-based teleoperation system that allows us to control the motion of the magnetic agents using microscopic feedback. This teleoperation is used to manipulate cell mockups toward reference positions in the presence and absence of contact between the cells and the magnetic agents. In addition, we demonstrate that iron oxide nanoparticles selectively move toward an MCF-7 cell and penetrate its walls without permanently damaging the membrane. This penetration is achieved in 28 seconds using controlled external magnetic fields and under microscopic vision guidance. The precise non-contact manipulation of biological cells using microparticles provides broad possibilities in targeted therapy and biomedical applications that require successful releases and selective penetration of cells without causing a permanent damage to the membrane.

Cancers

Lysosome-activated apoptosis represents an alternative method of overcoming tumor resistance compared to traditional forms of treatment. Pulsed magnetic fields open a new avenue for controlled and targeted initiation of lysosomal permeabilization in cancer cells via mechanical actuation of magnetic nanomaterials. In this study we used a noninvasive tool; namely, a benchtop pulsed magnetic system, which enabled remote activation of apoptosis in liver cancer cells. The magnetic system we designed represents a platform that can be used in a wide range of biomedical applications. We show that liver cancer cells can be loaded with superparamagnetic iron oxide nanoparticles (SPIONs). SPIONs retained in lysosomal compartments can be effectively actuated with a high intensity (up to 8 T), short pulse width (~15 µs), pulsed magnetic field (PMF), resulting in lysosomal membrane permeabilization (LMP) in cancer cells. We revealed that SPION-loaded lysosomes undergo LMP by assessing an increase...