Biological effects of carbon black nanoparticles are changed by surface coating with polycyclic aromatic hydrocarbons.
Carbon black nanoparticles (CBNP) are mainly composed of carbon, with a small amount of other elements (including hydrogen and oxygen). The toxicity of CBNP has been attributed to their large surface area, and through adsorbing intrinsically toxic substances, such as polycyclic aromatic hydrocarbons (PAH). It is not clear whether a PAH surface coating changes the toxicological properties of CBNP by influencing their physicochemical properties, through the specific toxicity of the surface-bound PAH, or by a combination of both.



Printex®90 (P90) was used as CBNP; the comparators were P90 coated with either benzo[a]pyrene (BaP) or 9-nitroanthracene (9NA), and soot from acetylene combustion that bears various PAHs on the surface (AS-PAH). Oxidative stress and IL-8/KC mRNA expression were determined in A549 and bronchial epithelial cells (16HBE14o-, Calu-3), mouse intrapulmonary airways and tracheal epithelial cells. Overall toxicity was tested in a rat inhalation study according to Organization for Economic Co-operation and Development (OECD) criteria. Effects on cytochrome monooxygenase (Cyp) mRNA expression, cell viability and mucociliary clearance were determined in acute exposure models using explanted murine trachea.



All particles had similar primary particle size, shape, hydrodynamic diameter and ζ-potential. All PAH-containing particles had a comparable specific surface area that was approximately one third that of P90. AS-PAH contained a mixture of PAH with expected higher toxicity than BaP or 9NA. PAH-coating reduced some effects of P90 such as IL-8 mRNA expression and oxidative stress in A549 cells, granulocyte influx in the in vivo OECD experiment, and agglomeration of P90 and mucus release in the murine trachea ex vivo. Furthermore, P90-BaP decreased particle transport speed compared to P90 at 10 μg/ml. In contrast, PAH-coating induced IL-8 mRNA expression in bronchial epithelial cell lines, and Cyp mRNA expression and apoptosis in tracheal epithelial cells. In line with the higher toxicity compared to P90-BaP and P90-9NA, AS-PAH had the strongest biological effects both ex vivo and in vivo.



Our results demonstrate that the biological effect of CBNP is determined by a combination of specific surface area and surface-bound PAH, and varies in different target cells.
Institut für Anatomie, Zentrum für medizinische Struktur- und Zellbiologie, Universität zu Lübeck (UzL), Airway Research Center North (ARCN), German Center for Lung Research (DZL), Ratzeburger Allee 160, 23562, Lübeck, Germany.
Karina
K
Lindner
Karlsruher Institut für Technologie, Engler-Bunte-Institut, Bereich Verbrennungstechnik, Karlsruhe, Germany.
Michael
M
Ströbele
Forschungszentrum Borstel, Leibniz-Zentrum für Medizin und Biowissenschaften, Experimentelle Pneumologie, Borstel, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Borstel, Germany.
Sandra
S
Schlick
Forschungszentrum Borstel, Leibniz-Zentrum für Medizin und Biowissenschaften, Experimentelle Pneumologie, Borstel, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Borstel, Germany.
Sina
S
Webering
Forschungszentrum Borstel, Leibniz-Zentrum für Medizin und Biowissenschaften, Angeborene Immunität, Borstel, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Borstel, Germany.
André
A
Jenckel
Fraunhofer Institut für Toxikologie und Experimentelle Medizin ITEM, Hannover, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.
Johannes
J
Kopf
Fraunhofer Institut für Toxikologie und Experimentelle Medizin ITEM, Hannover, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.
Olga
O
Danov
Fraunhofer Institut für Toxikologie und Experimentelle Medizin ITEM, Hannover, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.
Katherina
K
Sewald
Institut für Biomedizinische Optik, Universität zu Lübeck (UzL), Lübeck, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Lübeck, Germany.
Christian
C
Buj
Fraunhofer Institut für Toxikologie und Experimentelle Medizin ITEM, Hannover, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.
Otto
O
Creutzenberg
Fraunhofer Institut für Toxikologie und Experimentelle Medizin ITEM, Hannover, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.
Thomas
T
Tillmann
Fraunhofer Institut für Toxikologie und Experimentelle Medizin ITEM, Hannover, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.
Gerhard
G
Pohlmann
Fraunhofer Institut für Toxikologie und Experimentelle Medizin ITEM, Hannover, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.
Heinrich
H
Ernst
Fraunhofer Institut für Toxikologie und Experimentelle Medizin ITEM, Hannover, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.
Christina
C
Ziemann
Institut für Biomedizinische Optik, Universität zu Lübeck (UzL), Lübeck, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Lübeck, Germany.
Gereon
G
Hüttmann
Forschungszentrum Borstel, Leibniz-Zentrum für Medizin und Biowissenschaften, Angeborene Immunität, Borstel, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Borstel, Germany.
Holger
H
Heine
Karlsruher Institut für Technologie, Engler-Bunte-Institut, Bereich Verbrennungstechnik, Karlsruhe, Germany.
Henning
H
Bockhorn
Fraunhofer Institut für Toxikologie und Experimentelle Medizin ITEM, Hannover, Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.
Tanja
T
Hansen
Institut für Anatomie, Zentrum für medizinische Struktur- und Zellbiologie, Universität zu Lübeck (UzL), Airway Research Center North (ARCN), German Center for Lung Research (DZL), Ratzeburger Allee 160, 23562, Lübeck, Germany. Koenig@anat.uni-luebeck.de.
Peter
0000-0002-8155-7948
P
König
Forschungszentrum Borstel, Leibniz-Zentrum für Medizin und Biowissenschaften, Experimentelle Pneumologie, Borstel, Airway Research Center North (ARCN), German Center for Lung Research (DZL), Borstel, Germany.
Heinz
H
Fehrenbach
D000072283:A549 Cells; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D005260:Female; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects; D019570:Inhalation Exposure; D016209:Interleukin-8 / Q000378:metabolism; D008168:Lung / Q000187:drug effects / Q000276:immunology; D008297:Male; D008807:Mice, Inbred BALB C; D053758:Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D010316:Particle Size; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry / Q000633:toxicity*; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D053260:Soot / Q000737:chemistry / Q000633:toxicity*; D013499:Surface Properties; D014132:Trachea / Q000187:drug effects / Q000473:pathology
D016209:Interleukin-8; D011084:Polycyclic Aromatic Hydrocarbons; D017382:Reactive Oxygen Species; D053260:Soot
Airway epithelial cells; Carbon black nanoparticles; Cytotoxicity; Mucociliary clearance; Physicochemical characteristics; Polycyclic aromatic hydrocarbons