Ever-Evolving Identity of Magnetic Nanoparticles within Human Cells: The Interplay of Endosomal Confinement, Degradation, Storage, and Neocrystallization

Abstract

Considerable knowledge has been acquired in inorganic nanoparticles synthesis and nanoparticles potential use in biomedical applications. Among different materials, iron oxide nanoparticles remain unrivaled for several reasons. Not only they respond to multiple physical stimuli (e.g. magnetism, light) and they exert multifunctional therapeutic and diagnostic actions, but also they are biocompatible, and they integrate endogenous iron-related metabolic pathways. With the aim to optimize the use of (magnetic) iron oxide nanoparticles in biomedicine, different bio-physical phenomena have been recently identified and studied. Among them, the concept of "nanoparticle's identity" is of particular importance. Nanoparticles identities evolve in distinct biological environments and over different periods of time. In this account, we focus on the remodeling of magnetic nanoparticles identity following nanoparticles journey inside the cells. For instance, nanoparticles functions, such as heat generation or magnetic resonance imaging, can be highly impacted by endosomal confinement. Structural degradation of nanoparticles was also evidenced and quantified in cellulo and correlates with the loss of nanoparticles magnetic properties. Remarkably, in human stem cells, the nonmagnetic products of nanoparticles degradation could be subsequently reassembled into neosynthetized, endogenous magnetic nanoparticles. This stunning occurrence might account for magnetic particles naturally found in human organs, especially the brain. However, mechanistic details and the implication of such phenomena in homeostasis and disease have yet to be completely unraveled. This Account aims to assess the short and the long-term transformations of magnetic iron oxide nanoparticles in living cells, particularly focusing on human stem cells. Precisely, we herein overview the multiple and ever-evolving chemical, physical and biological magnetic nanoparticles identities and emphasize the remarkable intracellular fate of these nanoparticles.

Selective Magnetic Nanoheating: Combining Iron Oxide Nanoparticles for Multi-Hot-Spot Induction and Sequential Regulation

“…These materials present unique advantages in terms of contactless manipulation, reusability, and biocompatibility, since iron oxide can be easily digested and integrated by bioorganisms. 5 One of their most interesting features is the possibility of inducing local heat by irradiating them with alternating magnetic fields (AMFs). Besides, the MNPs can be prepared as magnetic colloids thanks to their lack of remanence (superparamagnetic regime) and being easily coated with biological components such as proteins or enzymes.…”

Principles and Applications of Single Particle Tracking in Cell Research

“…[37] The surface of these probes may be destroyed after endocytosed by cells, leading to a decreased stability and loss of targeting ability. [38] The degradation of CdTe QDs released toxic components such as Cd 2+ , resulting in further cell dysfunction and even apoptosis, [39] as well as the interruption of trajectories. To address the degradation of probes, several strategies have been proposed to improve their biostability in intracellular environment.…”

The Potential Application of Magnetic Nanoparticles for Liver Fibrosis Theranostics

“…Although iron oxide displays a moderate toxicity, its biodistribution, biotransformation, and circulation period in blood needs to be monitored (Van de Walle et al, 2020). The hybridization of iron oxide MNPs with different agents such as polymers, noble metals, silica dioxide, and non-magnetic oxides could pave the way to lessen their cytotoxicity (Lavorato et al, 2018;Efremova et al, 2018;Nguyen et al, 2018).…”