Comparative study of photothermolysis of cancer cells with nuclear-targeted or cytoplasm-targeted gold nanospheres: continuous wave or pulsed lasers.
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.
Georgia Institute of Technology, School of Chemistry and Biochemistry, Laser Dynamics Laboratory, 901 Atlantic Drive, Atlanta, Georgia 30332, USA.
Xiaohua
X
Huang
Bin
B
Kang
Wei
W
Qian
Megan A
MA
Mackey
Po C
PC
Chen
Adegboyega K
AK
Oyelere
Ivan H
IH
El-Sayed
Mostafa A
MA
El-Sayed
D002294:Carcinoma, Squamous Cell / Q000628:therapy; D016923:Cell Death / Q000528:radiation effects; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000528:radiation effects; D003593:Cytoplasm / Q000528:radiation effects; D006046:Gold / Q000627:therapeutic use*; D006801:Humans; D006979:Hyperthermia, Induced / Q000379:methods; D066298:In Vitro Techniques; D053685:Laser Therapy / Q000379:methods*; D053768:Metal Nanoparticles / Q000627:therapeutic use*; D009062:Mouth Neoplasms / Q000628:therapy; D055620:Optical Phenomena
D006046:Gold