Cell viability studies of PEG-thiol treated gold nanorods as optoacoustic contrast agents

Abstract

Rod shaped gold nanoparticles are synthesized using cetyltriammonium bromide (CTAB) as a major component of growth solutions. This surfactant is toxic to cells, but is at the moment unavoidable when monodisperse and high yield nanorods are to be synthesized. CTAB is found coating side walls of the nanoparticles and plays a role in maintaining colloidal stability. It may be displaced using thiolated PEG which is non-toxic to cells. Here we report on systematic studies of cell viability of such PEGylated nanorods on an SKBR3 cell-line using the MTS assay. These PEGylated particles are characterized using electron microscopy, optical spectroscopy and zeta potential measurements. It is expected that such treatment will be crucial in making nanorods compatible for in vivo biomedical applications.

Effect of Gold Nanorod Surface Chemistry on Cellular Response

“…6 Previous studies of various types of nanoparticles have indicated that their surface chemistry strongly influences cell toxicity and uptake. [8][9][10][11][12][13][14][15] GNR synthesis requires the surfactant cetyltrimethylammonium bromide (CTAB), 16 and GNR-CTAB not only have poor stability in biological solutions, but also exhibit significant cytotoxicity. 13,15,17,18 Several surface coatings have been proposed in order to reduce the apparent toxic effect of the GNRs, such as by "cloaking" the CTAB-GNRs with polyelectrolytes, 13 phospholipids, 5 or exchanging the CTAB with another molecule such as thiolated PEG.…”

A Comparative Study of Two Folate-Conjugated Gold Nanoparticles for Cancer Nanotechnology Applications

“…Methods may include increasing the nanoparticle size to take advantage of the Enhanced Permeability and Retention (EPR) effect of tumors and limiting free diffusion into healthy tissues. Also, PEGylation of the nanoconjugate may prevent recognition by the reticuloendothelial system and increase circulation time [ 21 ]. Third, methods of delivering the intense pulsed light to the tumors must be established.…”

“…For the in vivo stage of our proposed work we may use different shaped and sized AuNPs including the advanced Au nanorods [21] and Au nanoshells [22]. AuNPs heat up as a result of absorption of visible light, which makes them suitable for use in cancer photothermal treatment.…”

“…Due to its possibility of conjugation, non-immunogenic properties, and requirement for cancer cell growth, folate is a novel targeting agent for malignant tumors. For the in vivo stage of our proposed work we may use different shaped and sized AuNPs including the advanced Au nanorods [ 21 ] and Au nanoshells [ 22 ]. AuNPs heat up as a result of absorption of visible light, which makes them suitable for use in cancer photothermal treatment.…”

“…As a result of our research we have completed six research projects [ 25 , 26 , 27 , 28 , 29 , 30 ]. Meanwhile, two related papers by other groups [ 20 , 21 ] have reported on other folate-AuNP nanoconjugates. Here we report and compare two different folate-AuNP nanoconjugates that we have produced and tested.…”