Now showing 1 - 2 of 2
  • Publication
    Superparamagnetic Nanoparticles for the Assessment of Intracellular Nanoparticle-Cell Interactions
    (University College Dublin. School of Chemistry, 2022) ;
    Since their discovery, nanomaterials have been employed in an increasing number of products and applications. Thanks to their unique properties they enabled the advancement of many technologies and improved our lives under several aspects. Because of their nanometric dimensions, nanomaterials interact with the biological matter in a completely different way compared to their smaller (molecular scale) or larger (macro scale) counterparts. Despite the efforts of the scientific community in unravelling the network of machineries involved in the interaction of nanomaterials with the cells and human body, our understanding of the bio-nano interactions is still limited. The lack of knowledge around the dynamics that regulate the nanoparticles’ (NPs) trafficking in the human body is limiting the development of nanomedicine and, at the same time, is rising concerns in the regulatory bodies for the safe commercialisation of nanomaterial-based products. One of the main issues related to this critical gap in the knowledge is the lack of methodologies and tools that prevents unravelling the complexity of the bio-nano interactions. Techniques commonly used for the study of the intracellular dynamics result limiting for the study of the NPs intracellular trafficking for which the combination of different analysis and methodologies is required to obtain reliable and robust results. However, the correlation of data from different techniques is difficult when different NPs systems are used for the experiments. In this thesis, we develop new tools and methodologies for the study of the bio-nano interactions, exploiting one of the unique properties of iron oxide NPs, the superparamagnetism. In this context, superparamagnetic NPs are extremely useful tools because allow to label the machineries involved in the intracellular trafficking of NPs and enable their isolation from the biological matrix, which in order allows a more in-depth downstream analysis. To label the machineries involved in the intracellular trafficking with superparamagnetic NPs, two strategies are possible: exploiting the natural uptaking mechanisms of the cells or targeting specific compartments with NPs designed ad hoc. To exploit the first strategy, we designed multifunctional core-shell NPs with iron oxide multicores that provided the superparamagnetic properties and a silica shell doped with an organic fluorophore. Combining the magnetic and fluorescent properties in one nanoconstruct enabled to resolve the NPs intracellular trafficking by optical microscopy and to isolate the vesicles loaded with the NPs by magnetic separation, at different stages of their voyage inside the cell. The vesicles were then analysed with a set of technique to evaluate their integrity and functionality. To exploit the second strategy, we designed antibody grafted iron oxide NPs for the targeting of specific biological species. For this purpose, we adopted a thoughtful strategy of NPs surface modification that enabled the grafting of the antibody through bio-orthogonal chemistries, stabilise the particles in biological conditions, and limit the adsorption of undesired biomolecules typically responsible for NPs off-targeting. Although this second nanoconstruct is still under development, the preliminary results showed excellent targeting ability and specificity. Overall, the work presented in this thesis provides a solid base for the isolation, by magnetic separation, of biological species involved in the NPs intracellular trafficking and for the development of methodologies for the investigation of the machineries involved in the process.
  • Publication
    Understanding intracellular nanoparticle trafficking fates through spatiotemporally resolved magnetic nanoparticle recovery
    The field of nanomedicine has the potential to be a game-changer in global health, with possible applications in prevention, diagnostics, and therapeutics. However, despite extensive research focus and funding, the forecasted explosion of novel nanomedicines is yet to materialize. We believe that clinical translation is ultimately hampered by a lack of understanding of how nanoparticles really interact with biological systems. When placed in a biological environment, nanoparticles adsorb a biomolecular layer that defines their biological identity. The challenge for bionanoscience is therefore to understand the evolution of the interactions of the nanoparticle–biomolecules complex as the nanoparticle is trafficked through the intracellular environment. However, to progress on this route, scientists face major challenges associated with isolation of specific intracellular compartments for analysis, complicated by the diversity of trafficking events happening simultaneously and the lack of synchronization between individual events. In this perspective article, we reflect on how magnetic nanoparticles can help to tackle some of these challenges as part of an overall workflow and act as a useful platform to investigate the bionano interactions within the cell that contribute to this nanoscale decision making. We discuss both established and emerging techniques for the magnetic extraction of nanoparticles and how they can potentially be used as tools to study the intracellular journey of nanomaterials inside the cell, and their potential to probe nanoscale decision-making events. We outline the inherent limitations of these techniques when investigating particular bio-nano interactions along with proposed strategies to improve both specificity and resolution. We conclude by describing how the integration of magnetic nanoparticle recovery with sophisticated analysis at the single-particle level could be applied to resolve key questions for this field in the future.
      104Scopus© Citations 3