Now showing 1 - 6 of 6
  • Publication
    Regimes of Biomolecular Ultrasmall Nanoparticle Interactions
    Ultrasmall nanoparticles (USNPs), usually defined as NPs with core in the size range 1–3 nm, are a class of nanomaterials which show unique physicochemical properties, often different from larger NPs of the same material. Moreover, there are also indications that USNPs might have distinct properties in their biological interactions. For example, recent in vivo experiments suggest that some USNPs escape the liver, spleen, and kidney, in contrast to larger NPs that are strongly accumulated in the liver. Here, we present a simple approach to study the biomolecular interactions at the USNPs bio-nanointerface, opening up the possibility to systematically link these observations to microscopic molecular principles.
    Scopus© Citations 80  479
  • Publication
    Classification and biological identity of complex nano shapes
    Everywhere in our surroundings we increasingly come in contact with nanostructures that have distinctive complex shape features on a scale comparable to the particle itself. Such shape ensembles can be made by modern nano-synthetic methods and many industrial processes. With the ever growing universe of nanoscale shapes, names such as “nanoflowers” and “nanostars” no longer precisely describe or characterise the distinct nature of the particles. Here we capture and digitise particle shape information on the relevant size scale and create a condensed representation in which the essential shape features can be captured, recognized and correlated. We find the natural emergence of intrinsic shape groups as well-defined ensemble distributions and show how these may be analyzed and interpreted to reveal novel aspects of our nanoscale shape environment. We show how these ideas may be applied to the interaction between the nanoscale-shape and the living universe and provide a conceptual framework for the study of nanoscale shape biological recognition and identity.
      275Scopus© Citations 34
  • Publication
    Biological recognition of graphene nanoflakes
    The systematic study of nanoparticle-biological interactions requires particles to be reproducibly dispersed in relevant fluids along with further development in the identification of biologically relevant structural details at the materials-biology interface. Here, we develop a biocompatible long-term colloidally stable water dispersion of few-layered graphene nanoflakes in the biological exposure medium in which it will be studied. We also report the study of the orientation and functionality of key proteins of interest in the biolayer (corona) that are believed to mediate most of the early biological interactions. The evidence accumulated shows that graphene nanoflakes are rich in effective apolipoprotein A-I presentation, and we are able to map specific functional epitopes located in the C-terminal portion that are known to mediate the binding of high-density lipoprotein to binding sites in receptors that are abundant in the liver. This could suggest a way of connecting the materials' properties to the biological outcomes.
      357Scopus© Citations 70
  • Publication
    Synthesis, characterization and programmable toxicity of iron oxide nanoparticles conjugated with D-amino acid oxidase
    D-amino acid oxidase (DAAO) is an enzyme which generates reactive oxygen species (ROS) and it is believed to have potential uses as a novel therapeutic molecule if internalized by cancer cells or if they are localized close to their plasma membrane. When conjugated onto iron oxide nanoparticles (NPs), the enzyme can be magnetically directed to targeted locations with an increased efficacy. A subsequent injection of DAAO substrate D-alanine can initiate ROS production and induce apoptosis of cells surrounding the NP-DAAO complex. Here, we describe a platform for optimal bioconjugation using monodisperse γ-Fe2O3 NPs (∼10 nm) resulting in high DAAO loading, stable NP-DAAO dispersions and more than 90% enzymatic activity recovery, which is retained using the particles in human serum. Lastly, since the NP-DAAO system is designed for cancer therapy, we proved its efficacy in killing SKOV-3, U87 and HCT-116 cancer cells.
    Scopus© Citations 14  236
  • Publication
    Graphene Nanoflake Uptake Mediated by Scavenger Receptors
    The biological interactions of graphene have been extensively investigated over the last 10 years. However, very little is known about graphene interactions with the cell surface and how the graphene internalization process is driven and mediated by specific recognition sites at the interface with the cell. In this work, we propose a methodology to investigate direct molecular correlations between the biomolecular corona of graphene and specific cell receptors, showing that key protein recognition motifs, presented on the nanomaterial surface, can engage selectively with specific cell receptors. We consider the case of apolipoprotein A-I, found to be very abundant in the graphene protein corona, and observe that the uptake of graphene nanoflakes is somewhat increased in cells with greatly elevated expression of scavenger receptors B1, suggesting a possible mechanism of endogenous interaction. The uptake results, obtained by flow cytometry, have been confirmed using Raman microspectroscopic mapping, exploiting the strong Raman signature of graphene.
    Scopus© Citations 44  611
  • Publication
    Towards a classification strategy for complex nanostructures
    The range of possible nanostructures is so large and continuously growing, that collating and unifying the knowledge connected to them, including their biological activity, is a major challenge. Here we discuss a concept that is based on the connection of microscopic features of the nanomaterials to their biological impacts. We also consider what would be necessary to identify the features that control their biological interactions, and make them resemble each other in a biological context.
    Scopus© Citations 40  293