1. Cellular Toxicity of Carbon - based Nanomaterials Nano Letters, 2006, 6 (6), pp 1121–1125 Electrical Engineering and Computer Sciences University of California, Berkeley Arnaud Magrez, Sandor Kasas, Valérie Salicio, Nathalie Pasquier, Jin Won Seo, Marco Celio, Stefan Catsicas, Beat Schwaller, and László Forró Jaehyun Park EE235 Student Presentation 2 May 4, 2009

2. EE235 Student Presentation 2 2 Discovery of Numerous Nanomaterials CBNs (Carbon-based nanomaterials) such as carbon nanotubes / carbon fibers / carbon nanoparticles One of key elements in nanotechnology Backgrounds CBNs in Biological Applications Recently attracted much attention to DNA / proteins / drug delivery Lack of information concerning the potential hazards to CBN exposure In Vitro Toxicity of CBNs on Lung Cells Lung : directly exposed after inhalation of contaminated air – One of the first target organs of nanomaterials – Nanomaterials distribute in the whole respiratory tract To provide Information about Biocompatibility of Nanomaterials for in vitro research

3. May 4, 2009 EE235 Student Presentation 2 3 + MWCNTs Effect of CBNs on Cell Toxicity Various aspect ratios of CBNs MWCNTs (AR : 80-90) CNFs (AR : 30-40) Carbon black (AR : 1) Diluted in gelatin solution to avoid aggregation with 0.02µg/mL and 0.2 µg/mL Proliferation Curve for 3 Different Lung Tumor Cells + Carbon black + CNFs Shows similar behavior Two controls > Low concentration > High concentration Optical density ~ Number of cells H446 + CNFs showed the highest sensitivity and reproducibility

4. May 4, 2009 EE235 Student Presentation 2 4 Proliferation for H446 Cells with CBNs Toxicity of various CBNs Dose-dependent toxicity Toxicity : Aspect ratio dependent Carbon black > CNFs > MWCNTs : Filaments were less toxic than particles Toxicity appeared within 1 day Differences more pronounced for 5 days Toxicity ~ CBN dose

5. May 4, 2009 EE235 Student Presentation 2 5 Morphological Change Control Close cell-cell contacts Polygonal-shaped Lost mutual attachments Smaller & condensed nuclei Cytoplasm retracted With 0.02µg/mL of MWCNT CBNs caused typical irreversible cell injuries and cell death No specific morphological differences w.r.t. different CBNs

6. May 4, 2009 EE235 Student Presentation 2 6 Another Paper Supports Toxicity Jia el al., Cytotoxicity of carbon nanomaterials: single-wall nanotube, multi-wall nanotube, and fullerene, Environ. Sci. Technol. 39 (2005), pp. 1378–1383. Dose-Dependent Toxicity of CNTs in Alveolar Macrophage (AM) Toxicity : SWNTs > MWNT > Fullerenes (C 60 )

7. May 4, 2009 EE235 Student Presentation 2 7 Summary / Conclusion Nanomaterials MAY affect Toxicity of Cells Depends on aspect ratio : Filaments were less toxic than particles Depends on concentration : Higher concentration more toxic Toxicity : Still Debating Some papers showed no clear correlation between the biological impact of nanomaterials and their properties such as size, surface structure, crystalline phase, chemical composition, presence of metal trace impurities – Soto et al., Acta Biomaterialia, 2007 / Pulskamp et al., Tox. Letters, 2007 etc Every condition leads to a different biological response Different cell type would have different behavior Nanomaterials not always fully characterized before and during the experiment Conclusion More research needed to get more information Cell viability should be investigated carefully when the integration is needed