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Cellular Uptake and Cytotoxicity of Gold Nanorods: Molecular Origin of Cytotoxicity and Surface Effects
Author(s) -
Alkilany Alaaldin M.,
Nagaria Pratik K.,
Hexel Cole R.,
Shaw Timothy J.,
Murphy Catherine J.,
Wyatt Michael D.
Publication year - 2009
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.200801546
Subject(s) - nanorod , nanomaterials , cytotoxicity , pulmonary surfactant , surface charge , bovine serum albumin , bromide , nanoparticle , chemistry , nanotechnology , adsorption , materials science , chemical engineering , biophysics , in vitro , chromatography , inorganic chemistry , organic chemistry , biochemistry , engineering , biology
Gold nanorods of different aspect ratios are prepared using the growth‐directing surfactant, cetyltrimethylammonium bromide (CTAB), which forms a bilayer on the gold nanorod surface. Toxicological assays of CTAB‐capped nanorod solutions with human colon carcinoma cells (HT‐29) reveal that the apparent cytotoxicity is caused by free CTAB in solution. Overcoating the nanorods with polymers substantially reduces cytotoxicity. The number of nanorods taken up per cell, for the different surface coatings, is quantitated by inductively coupled plasma mass spectrometry on washed cells; the number of nanorods per cell varies from 50 to 2300, depending on the surface chemistry. Serum proteins from the biological media, most likely bovine serum albumin, adsorb to gold nanorods, leading to all nanorod samples bearing the same effective charge, regardless of the initial nanorod surface charge. The results suggest that physiochemical surface properties of nanomaterials change substantially after coming into contact with biological media. Such changes should be taken into consideration when examining the biological properties or environmental impact of nanoparticles.