Photo-induced Effects Of Carbon Nanotubes And Gold Nanoparticles, And The Fundamental Research Of Their Applications In Cancer Targeted Therapy

Carbon nanotubes and gold nanoparticles are typical nanomaterials that were actively pursured forapplication in a series of fields, especially in biomedical application. Based on their uniquephysicalchemical properties, carbon nanotubesa and gold nanoparticle have been considered todevelop new cancer diagnosis and therapy mechamisms, new targeting drug delivery systems and newbiomedical imaging techniques. This thesis focuses on the fundamental applications of carbonnanotubes and gold nanopartices in cancer targeted therapy. We mainly studied the photo-inducedeffects of carbon nanotubes and gold nanoparticls, and the potential applications in cancer treatments.More over, we also investigated the basic interaction of these materials with live cells, including thecellular uptake pathway, the intracellular distribution, and the effects on cell functions. The typicalresults and conclusions were summarized as follows:(1) We studied the large photoacoustic effect of carbon nanotubes in water solution, and discussedthe generation of photoacoustic shock wave. This result predicts that the carbon nanotubes might beused as photoacoustic agents in both biomedical photoacoustic imaging and treatment.(2) Based on the photoacoustic effect of carbon nanotubes we found above, we demonstratedcancer photoacoustic therapy by using carbon nanotubes as photoacoustic agents. Comparing withprevious photothermal technique, our photoacoustic technique reduced the laser energy about 1500times, which is critical to prevent normal cell from damaging.(3) We systemically studied the cellular uptake of carbon nanotubes, and investigated the cellulartocicity of carbon nanotubes from subcelluar level. We found the toxicity of carbon nanotubes to cellsand the mechamism of toxicity depend on the concentration of carbon nanotube.(4) We established the cellular uptake mechanisms of carbon naontubes with different diameter,length and surface modification. We also studied how these physical parameters of nanotubes affecttheir distribution and fate inside cells. These results provide important experimental evidence forunderstanding the basic interaction of carbon nanotubes and live cells.(5) By using Raman spectroscopy and fluorescence microscopy, we studied the circulation,accumlation and elimination behavior of carbon nanotubes inside mice. We further investigated thepossible damage to tissures caused by carbon nanotube accumlation.(6) We developed long-term live-cell imaging technique by using the surface plasmon scattering ofgold nanoparticles. This imaging method is useful to study the long-term behavior of live cells,including cell cycle and cell division. (7) We revealed the effect on cell functions with gold nanopaticle inside cell nucleus. We selectlytransport gold nanoparticles in to the nucleus of cancer cell, and further found that, the nuclear targinggold nanoparticle induce the cytokinesis arrest of cancer cells and thereby cause cell apoptosis.(8) We studied the laser energy theroshold in cancer photothermal therapy, by using different kindof laser and gold nanoparticles inside different location of cancer cells. We found the energy thresholdof signle-pulse nanosecond laser is 5×105 times lower than that of CW laser.