@article {1097, title = {Comparative study of photothermolysis of cancer cells with nuclear-targeted or cytoplasm-targeted gold nanospheres: continuous wave or pulsed lasers}, journal = {Journal of Biomedical Optics}, volume = {15}, number = {5}, year = {2010}, note = {Huang, Xiaohua Kang, Bin Qian, Wei Mackey, Megan A. Chen, Po C. Oyelere, Adegboyega K. El-Sayed, Ivan H. El-Sayed, Mostafa A.}, month = {Sep-Oct}, abstract = {We conduct a comparative study on the efficiency and cell death pathways of continuous wave (cw) and nanosecond pulsed laser photothermal cancer therapy using gold nanospheres delivered to either the cytoplasm or nucleus of cancer cells. Cytoplasm localization is achieved using arginine-glycine-aspartate peptide modified gold nanospheres, which target integrin receptors on the cell surface and are subsequently internalized by the cells. Nuclear delivery is achieved by conjugating the gold nanospheres with nuclear localization sequence peptides originating from the simian virus. Photothermal experiments show that cell death can be induced with a single pulse of a nanosecond laser more efficiently than with a cw laser. When the cw laser is applied, gold nanospheres localized in the cytoplasm are more effective in inducing cell destruction than gold nanospheres localized at the nucleus. The opposite effect is observed when the nanosecond pulsed laser is used, suggesting that plasmonic field enhancement of the nonlinear absorption processes occurs at high localization of gold nanospheres at the nucleus. Cell death pathways are further investigated via a standard apoptosis kit to show that the cell death mechanisms depend on the type of laser used. While the cw laser induces cell death via apoptosis, the nanosecond pulsed laser leads to cell necrosis. These studies add mechanistic insight to gold nanoparticle-based photothermal therapy of cancer. (c) 2010 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3486538]}, isbn = {1083-3668}, doi = {10.1117/1.3486538}, author = {Huang, Xiaohua and Kang, Bin and Qian, Wei and Mackey, M. A. and Chen, P. C. and Oyelere, A. K. and El Sayed, I.H. and El-Sayed, Mostafa A} } @article {1135, title = {Peptide-conjugated gold nanorods for nuclear targeting}, journal = {Bioconjugate Chemistry}, volume = {18}, number = {5}, year = {2007}, note = {Oyelere, Adegboyega K. Chen, Po C. Huang, Xiaohua El-Sayed, Ivan H. El-Sayed, Mostafa A.}, month = {Sep-Oct}, pages = {1490-1497}, abstract = {Resonant electron oscillations on the surface of noble metal nanoparticles (Au, Ag, Cu) create the surface plasmon resonance (SPR) that greatly enhances the absorption and Rayleigh (Mie) scattering of light by these particles. By adjusting the size and shape of the particles from spheres to rods, the SPR absorption and scattering can be tuned from the visible to the near-infrared region (NIR) where biologic tissues are relatively transparent. Further, gold nanorods greatly enhance surface Raman scattering of adsorbed molecules. These unique properties make gold nanorods especially attractive as optical sensors for biological and medical applications. In the present work, gold nanorods are covalently conjugated with a nuclear localization signal peptide through a thioalkyl-triazole linker and incubated with an immortalized benign epithelial cell line and an oral cancer cell line. Dark field light SPR scattering images demonstrate that nanorods are located in both the cytoplasm and nucleus of both cell lines. Single cell micro-Raman spectra reveal enhanced Raman bands of the peptide as well as molecules in the cytoplasm and the nucleus. Further, the Raman spectra reveal a difference between benign and cancer cell lines. This work represents an important step toward both imaging and Raman-based intracellular biosensing with covalently linked ligand-nanorod probes.}, isbn = {1043-1802}, doi = {10.1021/bc070132i}, author = {Oyelere, A. K. and Chen, P. C. and Huang, Xiaohua and El Sayed, I.H. and El-Sayed, Mostafa A} }