Iron oxide nanoparticles (IONPs) are being actively researched in various biomedical applications, particularly as magnetic resonance imaging (MRI) contrast agents for diagnosing various liver pathologies like nonalcoholic fatty liver diseases, nonalcoholic steatohepatitis, and cirrhosis. Emerging evidence suggests that IONPs may exacerbate hepatic steatosis and liver injury in susceptible livers such as those with nonalcoholic fatty liver disease. However, our understanding of how IONPs may affect steatotic cells at the sub-cellular level is still fragmented. Generally, there is a lack of studies identifying the molecular mechanisms of potential toxic and/or adverse effects of IONPs on "non-heathy" in vitro models. In this study, we demonstrate that IONPs, at a dose that does not cause general toxicity in hepatic cells (Alexander and HepG2), induce significant toxicity in steatotic cells (cells loaded with non-toxic doses of palmitic acid). Mechanistically, co-treatment with PA and IONPs resulted in endoplasmic reticulum (ER) stress, accompanied by the release of cathepsin B from lysosomes to the cytosol. The release of cathepsin B, along with ER stress, led to the activation of apoptotic cell death. Our results suggest that it is necessary to consider the interaction between IONPs and the liver, especially in susceptible livers. This study provides important basic knowledge for the future optimization of IONPs as MRI contrast agents for various biomedical applications.

• Publication type
• Journal Article MeSH

DNA nanotechnology has yielded remarkable advances in composite materials with diverse applications in biomedicine. The specificity and predictability of building 3D structures at the nanometer scale make DNA nanotechnology a promising tool for uses in biosensing, drug delivery, cell modulation, and bioimaging. However, for successful translation of DNA nanostructures to real-world applications, it is crucial to understand how they interact with living cells, and the consequences of such interactions. In this review, we summarize the current state of knowledge on the interactions of DNA nanostructures with cells. We identify key challenges, from a cell biology perspective, that influence progress towards the clinical translation of DNA nanostructures. We close by providing an outlook on what questions must be addressed to accelerate the clinical translation of DNA nanostructures. STATEMENT OF SIGNIFICANCE: Self-assembled DNA nanostructures (DNs) offers unique opportunities to overcome persistent challenges in the nanobiotechnology field. However, the interactions between engineered DNs and living cells are still not well defined. Critical systematization of current cellular models and biological responses triggered by DNs is a crucial foundation for the successful clinical translation of DNA nanostructures. Moreover, such an analysis will identify the pitfalls and challenges that are present in the field, and provide a basis for overcoming those challenges.

• Keywords
• Bionano interactions, Cellular uptake, Cytotoxicity, DNA nanotechnology, Nanotechnology, Protein corona,
• MeSH
• DNA chemistry   MeSH
• Drug Delivery Systems methods   MeSH
• Nanostructures * chemistry   MeSH
• Nanotechnology methods   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Review MeSH
• Names of Substances
• DNA MeSH

DNA nanostructures (DNs) can be designed in a controlled and programmable manner, and these structures are increasingly used in a variety of biomedical applications, such as the delivery of therapeutic agents. When exposed to biological liquids, most nanomaterials become covered by a protein corona, which in turn modulates their cellular uptake and the biological response they elicit. However, the interplay between living cells and designed DNs are still not well established. Namely, there are very limited studies that assess protein corona impact on DN biological activity. Here, we analyzed the uptake of functionalized DNs in three distinct hepatic cell lines. Our analysis indicates that cellular uptake is linearly dependent on the cell size. Further, we show that the protein corona determines the endolysosomal vesicle escape efficiency of DNs coated with an endosome escape peptide. Our study offers an important basis for future optimization of DNs as delivery systems for various biomedical applications.

• Keywords
• DNA nanotechnology, bionano interactions, cellular uptake, endolysosomal escape, nanotechnology, protein corona,
• MeSH
• Adsorption MeSH
• DNA chemistry   metabolism   MeSH
• Endosomes metabolism   MeSH
• Antimicrobial Cationic Peptides chemistry   metabolism   MeSH
• Nucleic Acid Conformation MeSH
• Humans MeSH
• Lysosomes metabolism   MeSH
• Cell Line, Tumor MeSH
• Nanostructures chemistry   MeSH
• Protein Corona chemistry   metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• aurein 1.2 peptide MeSH Browser
• DNA MeSH
• Antimicrobial Cationic Peptides MeSH
• Protein Corona MeSH

Iron oxide nanoparticles (IONs) are frequently used in various biomedical applications, in particular as magnetic resonance imaging contrast agents in liver imaging. Indeed, number of IONs have been withdrawn due to their poor clinical performance. Yet comprehensive understanding of their interactions with hepatocytes remains relatively limited. Here we investigated how iron oxide nanocubes (IO-cubes) and clusters of nanocubes (IO-clusters) affect distinct human hepatic cell lines. The viability of HepG2, Huh7 and Alexander cells was concentration-dependently decreased after exposure to either IO-cubes or IO-clusters. We found similar cytotoxicity levels in three cell lines triggered by both nanoparticle formulations. Our data indicate that different expression levels of Bcl-2 predispose cell death signaling mediated by nanoparticles. Both nanoparticles induced rather apoptosis than autophagy in HepG2. Contrary, IO-cubes and IO-clusters trigger distinct cell death signaling events in Alexander and Huh7 cells. Our data clarifies the mechanism by which cubic nanoparticles induce autophagic flux and the mechanism of subsequent toxicity. These findings imply that the cytotoxicity of ION-based contrast agents should be carefully considered, particularly in patients with liver diseases.

• Keywords
• Apoptosis, Autophagy, Cytotoxicity, Iron oxide nanoparticles, Magnetic resonance imaging,
• Publication type
• Journal Article MeSH

Iron oxide-based nanoparticles have been repeatedly shown to affect lysosomal-mediated signaling. Recently, nanoparticles have demonstrated an ability to modulate autophagic flux via lysosome-dependent signaling. However, the precise underlying mechanisms of such modulation as well as the impact of cellular genetic background remain enigmatic. In this study, we investigated how lysosomal-mediated signaling is affected by iron oxide nanoparticle uptake in three distinct hepatic cell lines. We found that nanoparticle-induced lysosomal dysfunction alters sub-cellular localization of pmTOR and p53 proteins. Our data indicate that alterations in the sub-cellular localization of p53 protein induced by nanoparticle greatly affect the autophagic flux. We found that cells with high levels of Bcl-2 are insensitive to autophagy initiated by nanoparticles. Altogether, our data identify lysosomes as a central hub that control nanoparticle-mediated responses in hepatic cells. Our results provide an important fundamental background for the future development of targeted nanoparticle-based therapies.

• Keywords
• autophagy, iron oxide nanoparticles, lysosomes, magnetic resonance imaging, nano-bio interactions, p53,
• MeSH
• Autophagy genetics   MeSH
• Cell Line MeSH
• Hepatocytes metabolism   MeSH
• Humans MeSH
• Lysosomes metabolism   MeSH
• Magnetic Iron Oxide Nanoparticles * MeSH
• Tumor Suppressor Protein p53 metabolism   MeSH
• Proto-Oncogene Proteins c-bcl-2 metabolism   MeSH
• TOR Serine-Threonine Kinases metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• BCL2 protein, human MeSH Browser
• MTOR protein, human MeSH Browser
• Tumor Suppressor Protein p53 MeSH
• Proto-Oncogene Proteins c-bcl-2 MeSH
• TOR Serine-Threonine Kinases MeSH