title: Adsorption of surfactant protein D from human respiratory secretions by carbon nanotubes and polystyrene nanoparticles depends on nanomaterial surface modification and size.
abstract: The alveolar respiratory unit constitutes one of the main targets of inhaled nanoparticles; the effect of engineered nanomaterials (NMs) on human health is largely unknown. Surfactant protein D (SP-D) is synthesized by alveolar type II epithelial cells and released into respiratory secretions; its main function is in immune defence, notably against inhaled microbes. SP-D also plays an important role in modulating an appropriate inflammatory response in the lung, and reduced SP-D is associated with a number of inflammatory lung diseases. Adsorption of SP-D to inhaled NMs may facilitate their removal via macrophage phagocytosis. This study addresses the hypothesis that the chemistry, size and surface modification of engineered NMs will impact on their interaction with, and adsorption of, SP-D. To this purpose, we have examined the interactions between SP-D in human lung lavage and two NMs, carbon nanotubes and polystyrene nanoparticles, with different surface functionalization. We have demonstrated that particle size, functionalization and concentration affect the adsorption of SP-D from human lung lavage. Functionalization with negatively charged groups enhanced the amount of SP-D binding. While SP-D binding would be expected to enhance macrophage phagocytosis, these results suggest that the degree of binding is markedly affected by the physicochemistry of the NM and that deposition of high levels of some nanoparticles within the alveolar unit might deplete SP-D levels and affect alveolar immune defence mechanisms.
authors.affiliation: National Heart and Lung Institute, Imperial College London, Dovehouse St., London SW3 6LY, UK Department of Technology and Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy magda.marchetti@iss.it.
authors.forename: Magda
authors.initials: M
authors.lastname: Marchetti
authors.affiliation: Department of Chemistry and London Centre for Nanotechnology, Imperial College London, Exhibition Road, London SW7 2AZ, UK.
authors.forename: Milo S P
authors.initials: MS
authors.lastname: Shaffer
authors.affiliation: National Heart and Lung Institute, Imperial College London, Dovehouse St., London SW3 6LY, UK.
authors.forename: Martina
authors.initials: M
authors.lastname: Zambianchi
authors.affiliation: Department of Materials and London Centre for Nanotechnology, Imperial College London, Exhibition Road, London SW7 2AZ, UK.
authors.forename: Shu
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Technology and Health, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
authors.forename: Fabiana
authors.initials: F
authors.lastname: Superti
authors.affiliation: Department of Environmental and Occupational Health, Rutgers School of Public Health, Piscataway, NJ 08854, USA.
authors.forename: Stephan
authors.initials: S
authors.lastname: Schwander
authors.affiliation: Department of Pharmacology and Toxicology, Rutgers University, Piscataway, NJ 08854, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Gow
authors.affiliation: Nicholas School of the Environment, Duke University, Durham, NC 27708, USA.
authors.forename: Junfeng Jim
authors.initials: JJ
authors.lastname: Zhang
authors.affiliation: National Heart and Lung Institute, Imperial College London, Dovehouse St., London SW3 6LY, UK.
authors.forename: Kian Fan
authors.initials: KF
authors.lastname: Chung
authors.affiliation: Department of Materials and London Centre for Nanotechnology, Imperial College London, Exhibition Road, London SW7 2AZ, UK.
authors.forename: Mary P
authors.initials: MP
authors.lastname: Ryan
authors.affiliation: Department of Materials and London Centre for Nanotechnology, Imperial College London, Exhibition Road, London SW7 2AZ, UK.
authors.forename: Alexandra E
authors.initials: AE
authors.lastname: Porter
authors.affiliation: National Heart and Lung Institute, Imperial College London, Dovehouse St., London SW3 6LY, UK t.tetley@imperial.ac.uk.
authors.forename: Teresa D
authors.initials: TD
authors.lastname: Tetley
mesh_terms: D000327:Adsorption; D001992:Bronchoalveolar Lavage Fluid; D006801:Humans; D053758:Nanoparticles / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010316:Particle Size; D011137:Polystyrenes / Q000737:chemistry*; D011485:Protein Binding; D037663:Pulmonary Surfactant-Associated Protein D / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D037742:Nanotubes, Carbon; D011137:Polystyrenes; D037663:Pulmonary Surfactant-Associated Protein D
keywords: carbon nanotubes; lung; polystyrene nanoparticles; surfactant protein D adsorption