Protein Corona Formation on Magnetite Nanoparticles: Effects of Culture Medium Composition, and Its Consequences on Superparamagnetic Nanoparticle Cytotoxicity

Modulating the toxicity of engineered nanoparticles by controlling protein corona formation: Recent advances and future prospects

With the rapid development and widespread application of engineered nanoparticles (ENPs), understanding the fundamental interactions between ENPs and biological systems is essential to assess and predict the fate of ENPs in vivo. When ENPs are exposed to complex physiological environments, biomolecules quickly and inevitably adsorb to ENPs to form a biomolecule corona, such as a protein corona (PC). The formed PC has a significant effect on the physicochemical properties of ENPs and gives them a brand new identity in the biological environment, which determines the subsequent ENP-cell/tissue/organ interactions. Controlling the formation of PCs is therefore of utmost importance to accurately predict and optimize the behavior of ENPs within living organisms, as well as ensure the safety of their applications. In this review, we provide an overview of the fundamental aspects of the PC, including the formation mechanism, composition, and frequently used characterization techniques. We comprehensively discuss the potential impact of the PC on ENP toxicity, including cytotoxicity, immune response, and so on. Additionally, we summarize recent advancements in manipulating PC formation on ENPs to achieve the desired biological outcomes. We further discuss the challenges and prospects, aiming to provide valuable insights for a better understanding and prediction of ENP behaviors in vivo, as well as the development of low-toxicity ENPs.

Synthesis and Characterization of a Biocompatible Nanoplatform Based on Silica-Embedded SPIONs Functionalized with Polydopamine

Superparamagnetic iron oxide nanoparticles (SPIONs) have gained increasing interest in nanomedicine, but most of those that have entered the clinical trials have been withdrawn due to toxicity concerns. Therefore, there is an urgent need to design low-risk and biocompatible SPION formulations. In this work, we present an original safe-by-design nanoplatform made of silica nanoparticles loaded with SPIONs and decorated with polydopamine (SPIONs@SiO2-PDA) and the study of its biocompatibility performance by an ad hoc thorough in vitro to in vivo nanotoxicological methodology. The results indicate that the SPIONs@SiO₂-PDA have excellent colloidal stability in serum-supplemented culture media, even after long-term (24 h) exposure, showing no cytotoxic or genotoxic effects in vitro and ex vivo. Physiological responses, evaluated in vivo using Caenorhabditis elegans as the animal model, showed no impact on fertility and embryonic viability, induction of an oxidative stress response, and a mild impact on animal locomotion. These tests indicate that the synergistic combination of the silica matrix and PDA coating we developed effectively protects the SPIONs, providing enhanced colloidal stability and excellent biocompatibility.

Direct capture and selective elution of a secreted polyglutamate-tagged nanobody using bare magnetic nanoparticles

BACKGROUND

The secretion and direct capture of proteins from the extracellular medium is a promising approach for purification, thus enabling integrated bioprocesses.

MAJOR RESULTS

We demonstrate the secretion of a nanobody (VHH) to the extracellular medium (EM) and its direct capture by bare, non-functionalized magnetic nanoparticles (MNPs). An ompA signal peptide for periplasmic localization, a polyglutamate-tag (E₈ ) for selective MNP binding, and a factor Xa protease cleavage site were fused N-terminally to the nanobody. The extracellular production of the E₈ -VHH (36 mg L^-1 ) was enabled using a growth-decoupled Escherichia coli-based expression system. The direct binding of E₈ -VHH to the bare magnetic nanoparticles was possible and could be drastically improved up to a yield of 88% by adding polyethylene glycol (PEG). The selectivity of the polyglutamate-tag enabled a selective elution of the E₈ -VHH from the bare MNPs while raising the concentration factor (5x) and purification factor (4x) significantly.

CONCLUSION

Our studies clearly show that the unique combination of a growth-decoupled E. coli secretion system, the polyglutamate affinity tag, non-functionalized magnetic nanoparticles, and affinity magnetic precipitation is an innovative and novel way to capture and concentrate nanobodies. This article is protected by copyright. All rights reserved.

Nanoparticle-protein corona complex: understanding multiple interactions between environmental factors, corona formation, and biological activity

The surfaces of pristine nanoparticles become rapidly coated by proteins in biological fluids, forming the so-called protein corona. The corona modifies key physicochemical characteristics of nanoparticle surfaces that modulate its biological and pharmacokinetic activity, biodistribution, and safety. In the two decades since the protein corona was identified, the importance of nanoparticles surface properties in regulating biological responses have been recognized. However, there is still a lack of clarity about the relationships between physiological conditions and corona composition over time, and how this controls biological activities/interactions. Here we review recent progress in characterizing the structure and composition of protein corona as a function of biological fluid and time. We summarize the influence of nanoparticle characteristics on protein corona composition and discuss the relevance of protein corona to the biological activity and fate of nanoparticles. The aim is to provide a critical summary of the key factors that affect protein corona formation (e.g. characteristics of nanoparticles and biological environment) and how the corona modulates biological activity, cellular uptake, biodistribution, and drug delivery. In addition to a discussion on the importance of the characterization of protein corona adsorbed on nanoparticle surfaces under conditions that mimic relevant physiological environment, we discuss the unresolved technical issues related to the characterization of nanoparticle-protein corona complexes during their journey in the body. Lastly, the paper offers a perspective on how the existing nanomaterial toxicity data obtained from in vitro studies should be reconsidered in the light of the presence of a protein corona, and how recent advances in fields, such as proteomics and machine learning can be integrated into the quantitative analysis of protein corona components.

The Fate of Nanoparticles In Vivo and the Strategy of Designing Stealth Nanoparticle for Drug Delivery

Nano-drug delivery systems (Nano-DDS) offer powerful advantages in drug delivery and targeted therapy for diseases. Compared to the traditional drug formulations, Nano-DDS can increase solubility, biocompatibility, and reduce off-targeted side effects of free drugs. However, they still have some disadvantages that pose a limitation in reaching their full potential in clinical use. Protein adsorption in blood, activation of the complement system, and subsequent sequestration by the mononuclear phagocyte system (MPS) consequently result in nanoparticles (NPs) to be rapidly cleared from circulation. Therefore, NPs have low drug delivery efficiency. So, it is important to develop stealth NPs for reducing bio-nano interaction. In this review, we first conclude the interaction between NPs and biological environments, such as blood proteins and MPS, and factors influencing each other. Next, we will summarize the new strategies to reduce NPs protein adsorption and uptake by the MPS based on current knowledge of the bio-nano interaction. Further directions will also be highlighted for the development of biomimetic stealth nano-delivery systems by combining targeted strategies for a better therapeutic effect.

Protein nanoparticles in drug delivery: animal protein, plant proteins and protein cages, albumin nanoparticles

In this article, we will describe the properties of albumin and its biological functions, types of sources that can be used to produce albumin nanoparticles, methods of producing albumin nanoparticles, its therapeutic applications and the importance of albumin nanoparticles in the production of pharmaceutical formulations. In view of the increasing use of Abraxane and its approval for use in the treatment of several types of cancer and during the final stages of clinical trials for other cancers, to evaluate it and compare its effectiveness with conventional non formulations of chemotherapy Paclitaxel is paid. In this article, we will examine the role and importance of animal proteins in Nano medicine and the various benefits of these biomolecules for the preparation of drug delivery carriers and the characteristics of plant protein Nano carriers and protein Nano cages and their potentials in diagnosis and treatment. Finally, the advantages and disadvantages of protein nanoparticles are mentioned, as well as the methods of production of albumin nanoparticles, its therapeutic applications and the importance of albumin nanoparticles in the production of pharmaceutical formulations.

Biological effects of formation of protein corona onto nanoparticles

Administration of nanomaterials based medicinal and drug carrier systems into systemic circulation brings about interaction of blood components e.g. albumin and globulin proteins with these nanosystems. These blood or serum proteins either get loosely attached over these nanocarriers and form soft protein corona or are tightly adsorbed over nanoparticles and hard protein corona formation occurs. Formation of protein corona has significant implications over a wide array of physicochemical and medicinal attributes. Almost all pharmacological, toxicological and carrier characteristics of nanoparticles get prominently touched by the protein corona formation. It is this interaction of nanoparticle protein corona that decides and influences fate of nanomaterials-based systems. In this article, authors reviewed several diverse aspects of protein corona formation and its implications on various possible outcomes in vivo and in vitro. A brief description regarding formation and types of protein corona has been included along with mechanisms and pharmacokinetic, pharmacological behavior and toxicological profiles of nanoparticles has been described. Finally, significance of protein corona in context of its in vivo and in vitro behavior, involvement of biomolecules at nanoparticle plasma interface and other interfaces and effects of protein corona on biocompatibility characteristics have also been touched upon.

Insights into Characterization Methods and Biomedical Applications of Nanoparticle-Protein Corona

Nanoparticles (NPs) exposed to a biological milieu will strongly interact with proteins, forming "coronas" on the surfaces of the NPs. The protein coronas (PCs) affect the properties of the NPs and provide a new biological identity to the particles in the biological environment. The characterization of NP-PC complexes has attracted enormous research attention, owing to the crucial effects of the properties of an NP-PC on its interactions with living systems, as well as the diverse applications of NP-PC complexes. The analysis of NP-PC complexes without a well-considered approach will inevitably lead to misunderstandings and inappropriate applications of NPs. This review introduces methods for the characterization of NP-PC complexes and investigates their recent applications in biomedicine. Furthermore, the review evaluates these characterization methods based on comprehensive critical views and provides future perspectives regarding the applications of NP-PC complexes.

Recent advances in the analysis of nanoparticle-protein coronas

In spite of radical advances in nanobiotechnology, the clinical translation of nanoparticle (NP)-based agents is still a major challenge due to various physiological factors that influence their interactions with biological systems. Recent decade witnessed meticulous investigation on protein corona (PC) that is the first surrounds NPs once administered into the body. Formation of PC around NP surface exhibits resilient effects on their circulation, distribution, therapeutic activity, toxicity and other factors. Although enormous literature is available on the role of PC in altering pharmacokinetics and pharmacodynamics of NPs, understanding on its analytical characterization methods still remains shallow. Therefore, the current review summarizes the impact of PC on biological fate of NPs and stressing on analytical methods employed for studying the NP-PC.

Mapping the heterogeneity of protein corona by ex vivo magnetic levitation

In the past decade, we witnessed limited success in the clinical translation of therapeutic nanoparticles (NPs). One of the main reasons for this limited success is our poor understanding of the biological identity of NPs. Herein, we report magnetic levitation (MagLev) as a complementary analytical tool to investigate the homogeneity of the created protein corona (PC) coated NPs through an ex vivo model. Our results demonstrate that the MagLev system not only has the capacity to separate corona coated NPs, but also enables us to study the homogeneity/heterogeneity of the PC. Our findings suggest that current ex vivo isolation methods cause a heterogeneous coverage of PC profiles at the surface of NPs. The MagLev technique, therefore, would be instrumental in identifying and separating fully PC coated NPs which, in turn, enables us to achieve more accurate information on protein corona composition. Ultimately, we believe that the MagLev technique can be used for the fast screening of the homogeneity of corona coated NPs before quantitative analysis of the corona profile/composition, hence definitely improving our fundamental understanding of nano-bio interfaces.

Effects of starch-coating of magnetite nanoparticles on cellular uptake, toxicity and gene expression profiles in adult zebrafish

Engineered magnetite nanoparticles (Fe₃O₄ NPs) have been used in many fields. To prevent particle agglomeration, stabilizers or coatings are often required. While such coatings have been shown to enhance performances, the environmental impact or toxicity of stabilized or coated Fe₃O₄ NPs remain poorly understood. In an effort to understand the impacts of such coatings on the toxicity of Fe₃O₄ NPs, we used the transcriptome sequencing (RNA-seq) technique to characterize the gill and liver transcriptomes from adult zebrafish when exposed to bare and starch-stabilized Fe₃O₄ NPs for 7days, demonstrating remarkable differences in gene expression profiles, also known as differentially expressed genes (DEGs) profiles, in both tissues. Bare Fe₃O₄ NPs exerted greater toxicity than starch-coated Fe₃O₄ NPs in gill; in contrast, starch-Fe₃O₄ NPs triggered more severe damage on liver, though both bare and stabilized NPs appeared to share similar regulatory mechanisms. Quantitative real-time polymerase chain reactions using six genes each for the two tissues verified the RNA-seq results. The surface coatings play an important role in determining the nanoparticle toxicity, which in turn modulate cell uptake and biological responses, consequently impacting the potential safety and efficacy of nanomaterials.

Techniques for the experimental investigation of the protein corona

Due to its enormous relevance the corona formation of adsorbed proteins around nanoparticles is widely investigated. A comparison of different experimental techniques is given. Direct measurements of proteins, such as typically performed with mass spectrometry, will be compared with indirect analysis, in which instead information about the protein corona is gathered from changes in the properties of the nanoparticles. The type of measurement determines also whether before analysis purification from unbound excess proteins is necessary, which may change the equilibrium, or if measurements can be performed in situ without required purification. Pros and contras of the different methods will be discussed.

Environmental implications and applications of engineered nanoscale magnetite and its hybrid nanocomposites: A review of recent literature

This review focuses on environmental implications and applications of engineered magnetite (Fe3O4) nanoparticles (MNPs) as a single phase or a component of a hybrid nanocomposite that exhibits superparamagnetism and high surface area. MNPs are synthesized via co-precipitation, thermal decomposition and combustion, hydrothermal process, emulsion, microbial process, and green approaches. Aggregation/sedimentation and transport of MNPs depend on surface charge of MNPs and geochemical parameters such as pH, ionic strength, and organic matter. MNPs generally have low toxicity to humans and ecosystem. MNPs are used for constructing chemical/biosensors and for catalyzing a variety of chemical reactions. MNPs are used for air cleanup and carbon sequestration. MNP nanocomposites are designed as antimicrobial agents for water disinfection and flocculants for water treatment. Conjugated MNPs are widely used for adsorptive/separative removal of organics, dyes, oil, arsenic, phosphate, molybdate, fluoride, selenium, Cr(VI), heavy metal cations, radionuclides, and rare earth elements. MNPs can degrade organic/inorganic contaminants via chemical reduction or catalyze chemical oxidation in water, sediment, and soil. Future studies should further explore mechanisms of MNP interactions with other nanomaterials and contaminants, economic and green approaches of MNP synthesis, and field scale demonstration of MNP utilization.

Biomolecular environment, quantification, and intracellular interaction of multifunctional magnetic SERS nanoprobes

Multifunctional composite nanoprobes consisting of iron oxide nanoparticles linked to silver and gold nanoparticles, Ag-Magnetite and Au-Magnetite, respectively, were introduced by endocytic uptake into cultured fibroblast cells. The cells containing the non-toxic nanoprobes were shown to be displaceable in an external magnetic field and can be manipulated in microfluidic channels. The distribution of the composite nanostructures that are contained in the endosomal system is discussed on the basis of surface-enhanced Raman scattering (SERS) mapping, quantitative laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) micromapping, and cryo soft X-ray tomography (cryo soft-XRT). Cryo soft-XRT of intact, vitrified cells reveals that the composite nanoprobes form intra-endosomal aggregates. The nanoprobes provide SERS signals from the biomolecular composition of their surface in the endosomal environment. The SERS data indicate the high stability of the nanoprobes and of their plasmonic properties in the harsh environment of endosomes and lysosomes. The spectra point at the molecular composition at the surface of the Ag-Magnetite and Au-Magnetite nanostructures that is very similar to that of other composite structures, but different from the composition of pure silver and gold SERS nanoprobes used for intracellular investigations. As shown by the LA-ICP-MS data, the uptake efficiency of the magnetite composites is approximately two to three times higher than that of the pure gold and silver nanoparticles.

Human alveolar epithelial cell responses to core-shell superparamagnetic iron oxide nanoparticles (SPIONs)

Superparamagnetic iron oxide nanoparticles (SPIONs) have been prepared and coated with positively (-NH3(+)) and negatively (-COO(-)) charged shells. These NPs, as well as their "bare" precursor, which actually contain surface hydroxyl groups, have been characterized in vitro, and their influence on a human epithelial cell line has been assessed in terms of cell metabolic activity, cellular membrane lysis, mitochondrial activity, and reactive oxygen species production. Their physicochemical characterizations and protein-nanoparticle interactions have been determined using dynamic light scattering, high-resolution transmission electron microscopy, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) spectrometry, and Coomassie Blue fast staining. Cell-SPION interactions have been determined by PrestoBlue resazurin-based, Trypan Blue dye exclusion-based, and MTS cell proliferation assays as well as by reactive oxygen species determination. The results show that different surface characteristics cause different protein corona and cell responses. Some proteins (e.g., albumin) are adsorbed only on positively charged coatings and others (e.g., fibrinogen) only on negatively charged coating. No cell deaths occur, but cell proliferation is influenced by surface chemistry. Proliferation reduction is dose dependent and highest for bare SPIONs. Negatively charged SPIONs were the most biocompatible.