Detoxification of Gold Nanorods by Treatment with Polystyrenesulfonate

作者：Leonov Alexei P; Zheng Jiwen; Clogston Jeffrey D; Stern Stephan T; Patri Anil K; Wei Alexander^*

来源：ACS Nano, 2008, 2(12): 2481-2488.

DOI：10.1021/nn800466c

• nanorods
• nanomedicine
• nanobiotechnology
• toxicity
• dispersion stability

We address an outstanding issue associated with the biocompatibility of gold nanorods (GNRs), a promising agent for biomedical imaging and theragnostics. GNRs are typically prepared in the presence of cetyltrimethylammoniurn bromide (CTAB), a cationic surfactant whose rigorous removal is necessary due to its cytotoxicity and membrane-compromising properties. CTAB-stabilized GNRs can be partially purified by treatment with polystyrenesulfonate (PSS), an anionic polyelectrolyte often used as a surrogate peptizing agent, followed by chloroform extraction and ultrafiltration with minimal loss of dispersion stability. However, in vitro cytotoxicity assays of PSS-coated GNRs revealed IC(50) values in the low to submicromolar range, with subsequent studies indicating the source of toxicity to be associated with a persistent PSS-CTAB complex. Further exchange of CTAB-laden PSS with fresh polyelectrolyte greatly improves biocompatibility, to the extent that 85 mu g/mL of "CTAB-free" GNRs (the highest level evaluated) has comparable toxicity to a standard phosphate buffer solution. Ironically, PSS is not effective by itself at stabilizing GNRs in CTAB-depleted suspensions: while useful as a detergent for GNR detoxification, it should be replaced by more robust coatings for long-term stability under physiological conditions.

• 出版日期2008-12