Magneto-Mechanical Approach in Biomedicine: Benefits, Challenges, and Future Perspectives

Abstract

The magneto-mechanical approach is a powerful technique used in many different applications in biomedicine, including remote control enzyme activity, cell receptors, cancer-selective treatments, mechanically-activated drug releases, etc. This approach is based on the use of a combination of magnetic nanoparticles and external magnetic fields that have led to the movement of such nanoparticles with torques and forces (enough to change the conformation of biomolecules or even break weak chemical bonds). However, despite many theoretical and experimental works on this topic, it is difficult to predict the magneto-mechanical effects in each particular case, while the important results are scattered and often cannot be translated to other experiments. The main reason is that the magneto-mechanical effect is extremely sensitive to changes in any parameter of magnetic nanoparticles and the environment and changes in the parameters of the applied magnetic field. Thus, in this review, we (1) summarize and propose a simplified theoretical explanation of the main factors affecting the efficiency of the magneto-mechanical approach; (2) discuss the nature of the MNP-mediated mechanical forces and their order of magnitude; (3) show some of the main applications of the magneto-mechanical approach in the control over the properties of biological systems.

Multifunctional Anisotropic Rod-Shaped CoFe2O4 Nanoparticles for Magnetic Resonance Imaging and Magnetomechanical Therapy

“…Interestingly, our data show that the magnetomechanical effect from the rod-shaped NPs was already achieved at a concentration of 6 μg•mL −1 after 1 h of LF-AMF exposure (f = 31 Hz, B = 100 mT), while no cytotoxic effects at the same concentration of NPs were observed for untreated cells. This value of NP concentration, resulting in decreasing cell viability in magnetomechanical experiments, is the order of magnitude less than the similar concentration of spherical NPs, previously mentioned in other works, 53 while the enhanced magnetomechanical effect may be the result of high shape anisotropy of rod-shaped CF@NaOH/ ann NPs. With an increase in the concentration of NPs, they themselves begin to show a weak toxic effect.…”

“…The rod-shaped morphology and high value of the anisotropy energy barrier K eff V NP of CF@NaOH/ann NPs also favor their application as transductors of the energy of the low-frequency alternating magnetic fields into mechanical energy, which is applied in remote magnetomechanical actuation of biomolecules and cancer cell destruction . Noninvasive nature and deep tissue penetration of magnetic fields make magnetomechanical actuation stand out among other stimulation techniques.…”

“…52 The rod-shaped morphology and high value of the anisotropy energy barrier K eff V NP of CF@NaOH/ann NPs also favor their application as transductors of the energy of the low-frequency alternating magnetic fields into mechanical energy, which is applied in remote magnetomechanical actuation of biomolecules and cancer cell destruction. 53 Noninvasive nature and deep tissue penetration of magnetic fields make magnetomechanical actuation stand out among other stimulation techniques. Before assessing 4T1 cell viability in vitro after LF-AMF exposure with NPs, we estimated the magnitude of the magnetic torque and stretching force that can be generated by the CF@NaOH/ann NPs as a result of their rotational−vibrational movements and affect the integrity and structural changes of the cell membrane.…”

“…54,55 However, the calculated value is quite sufficient to cause cytoskeletal disruption, compromise the integrity of the cellular membrane, trigger programmed cell death, and also cause a sharp increase in the level of intracellular Ca 2+ . 18,53 Analysis of TEM micrographs of 4T1 cells incubated with NPs without following LF-AMF exposure revealed NP conglomerates of various sizes inside the cells. These conglomerates were localized directly in the cell cytoplasm (Figure 4d(1,2)) or inside endolysosomes (Figure 4d (3,4)).…”

Novel candidate theranostic radiopharmaceutical based on strontium hexaferrite nanoparticles conjugated with azacrown ligand

“…[39][40][41][42] This effect is called magnetomechanical therapy. [43][44][45] Several studies have already demonstrated that nano-and micrometre-sized particles with different shapes induce the death of cancer cells upon low-frequency alternating or rotating magnetic fields. [46][47][48][49][50][51] However, the study 52 reports an insignificant effect of the magnetomechanical effect on cell viability with the application of micrometre particles, while nanoparticles increase the destroyed cell rate to 30% among cells with internalized particles.…”