CONSPECTUS
There are a growing range of innovations in the field of nanobiotechnology and nanomedicine. However, the increased number of engineered nanomaterials (ENMs) and their novel physicochemical properties pose a new challenge of understanding the full spectrum of their interactions at the nano/bio interface, including the potential to engage in hazardous interactions. A comprehensive understanding of these interactions is required, including the physicochemical properties that control bioavailability and how this knowledge could be used for safer nanomaterial design. To this end, considerable knowledge generation and exploration is required to understand how material properties influence ENM uptake, transport and fate, as well as the biological consequences of these interactions at cellular level. The toxicity mechanisms of different ENMs differ with nanosize/nanosurface which directly correlates to the physicochemical activities of ENMs in vivo. So, to explore their underlying physicochemical processes of ENMs in cells will be essentially helpful for definitely understanding the toxicity of ENMs. In addition, the in vitro results are indispensable for modeling the biokinetics of ENMs. Nevertheless, we need to proceed such extrapolation with due caution, because the dosage relevance between the in vitro and in vivo exposure largely influences outcomes of the toxic response.
In this Account, we delineate our view of the impact of ENM physicochemical properties on cellular bioprocessing based on the research performed in our laboratories. Because organic, inorganic, and hybrid ENMs can be produced in various sizes, shapes, surface modifications and compositions, and their widely tunable compositions and structures that can be dynamically modified under different biological and environmental use conditions. Therefore, a description of how ENM chemical properties such as (1) hydrophobicity and hydropholicity, (2) material composition, (3) surface functionalization and charge, (4) dispersal state, and (5) adsorption of proteins on the surface determine ENM cellular uptake, intracellular biotransformation, and bioelimination or bioaccumulation, were included. We will also review how physical properties such as size, aspect ratio and surface area influence these interactions and their potential risks. We discuss this conceptual framework from the perspective of actual experimental findings and show how tuning of these properties can be used to control the uptake, biotransformation, fate and hazard of ENMs. The current review on ENM biological behavior and safety issues will provide specific and concentrated information with the principles of both nano-bio interactions and dominating natural biological rules. This knowledge gathering also assists us in developing safer nanotherapeutics and guiding the design of new materials that can execute novel functions at the nano-bio interface.