Toward a deeper and simpler understanding of serum protein-mediated transformations of magnetic nanoparticles by ICP-MS

Fe3O4SPIONs in cancer theranostics-structure versus interactions with proteins and methods of their investigation

As the second leading cause of death worldwide, neoplastic diseases are one of the biggest challenges for public health care. Contemporary medicine seeks potential tools for fighting cancer within nanomedicine, as various nanomaterials can be used for both diagnostics and therapies. Among those of particular interest are superparamagnetic iron oxide nanoparticles (SPIONs), due to their unique magnetic properties,. However, while the number of new SPIONs, suitably modified and functionalized, designed for medical purposes, has been gradually increasing, it has not yet been translated into the number of approved clinical solutions. The presented review covers various issues related to SPIONs of potential theranostic applications. It refers to structural considerations (the nanoparticle core, most often used modifications and functionalizations) and the ways of characterizing newly designed nanoparticles. The discussion about the phenomenon of protein corona formation leads to the conclusion that the scarcity of proper tools to investigate the interactions between SPIONs and human serum proteins is the reason for difficulties in introducing them into clinical applications. The review emphasizes the importance of understanding the mechanism behind the protein corona formation, as it has a crucial impact on the effectiveness of designed SPIONs in the physiological environment.

The Potential of ICP-MS as a Complementary Tool in Nanoparticle-Protein Corona Analysis

The prolific applicability of nanomaterials has made them a common citizen in biological systems, where they interact with proteins forming a biological corona complex. These complexes drive the interaction of nanomaterials with and within the cells, bringing forward numerous potential applications in nanobiomedicine, but also arising toxicological issues and concerns. Proper characterization of the protein corona complex is a great challenge typically handled with the combination of several techniques. Surprisingly, despite inductively coupled plasma mass spectrometry (ICP-MS) being a powerful quantitative technique whose application in nanomaterials characterization and quantification has been consolidated in the last decade, its application to nanoparticle-protein corona studies is scarce. Furthermore, in the last decades, ICP-MS has experienced a turning point in its capabilities for protein quantification through sulfur detection, hence becoming a generic quantitative detector. In this regard, we would like to introduce the potential of ICP-MS in the nanoparticle protein corona complex characterization and quantification complementary to current methods and protocols.

Red Flags and Adversities on the Way to the Robust CE-ICP-MS/MS Quantitative Monitoring of Self-Synthesized Magnetic Iron Oxide(II, III)-Based Nanoparticle Interactions with Human Serum Proteins

The growing interest in superparamagnetic iron oxide nanoparticles (SPIONs) as potential theranostic agents is related to their unique properties and the broad range of possibilities for their surface functionalization. However, despite the rapidly expanding list of novel SPIONs with potential biomedical applications, there is still a lack of methodologies that would allow in-depth investigation of the interactions of those nanoparticles with biological compounds in human serum. Herein, we present attempts to employ capillary electrophoresis-inductively coupled plasma tandem mass spectrometry (CE-ICP-MS/MS) for this purpose and various obstacles and limitations noticed during the research. The CE and ICP-MS/MS parameters were optimized, and the developed method was used to study the interactions of two different proteins (albumin and transferrin) with various synthesized SPIONs. While the satisfactory resolution between proteins was obtained and the method was applied to examine individual reagents, it was revealed that the conjugates formed during the incubation of the proteins with SPIONs were not stable under the conditions of electrophoretic separation.

Protein-Mediated Transformations of Superparamagnetic Nanoparticles Evidenced by Single-Particle Inductively Coupled Plasma Tandem Mass Spectrometry: A Disaggregation Phenomenon

Progress toward translating superparamagnetic iron oxide nanoparticles (SPIONs) with specific diagnostic and therapeutic properties for clinical applications depends on developing and implementing appropriate methodologies that would allow in-depth characterizations of their behavior in a real biological environment. Herein, we report a versatile approach for studying interactions between SPIONs and proteins using single-particle inductively coupled plasma tandem mass spectrometry. By monitoring the changes in the size distribution upon exposure to human serum, the formation of stable protein corona is revealed, accompanied by particle disaggregation.

Magnetic nanoparticles for highly robust, facile and efficient loading of metal-based drugs

Direct interaction between iron oxide nanoparticles (IONs), modified with polyethylene glycol and an ionic liquid, and activated cisplatin drug resulted in a fast and high drug loading (up to 0.17 mol of platinum per gram of iron), and the payload does not strongly affect the magnetic properties of IONs and resists protein adsorption in human serum environment. For another, developmental metal-based drug, tris(8-quinolinolato)gallium(III), binding to the IONs allowed for overcoming the disadvantages of low solubility and incompatibility with intravenous administration. The potential of IONs as a magnetic nanoformulation for smart drug delivery has been confirmed by the release of both metallodrugs under conditions relevant to cancer cytosol.