| Cancer is one of the major diseases affecting human health. Since the mechanism of the tumor formation is very complex, early diagnosis of cancer is difficult. Furthermore, limited clinical treatments including chemotherapy, radiotherapy, and surgical treatment lead to many problems in cancer therapy. Emerging nano-materials demonstrate a new application area, including the ultra-sensitive molecular imaging in vivo, hyperthermia, targeted drug delivery, drug release and efficacy of rapid evaluation .because of their small size and unique physical and chemical properties for the diagnosis and treatment of tumors. They are expected to overcome the limitations of existing cancer treatments. Currently, nano-materials for cancer hyperthermia are usually magnetic nanoparticles, gold, silver and other heavy metal nano-devices (such as the gold ball, gold rod, gold and gold ball cage shell particles, etc.). In use, the nano-particles bind to the appropriate ligand by chemical coupling or physical adsorption to achieve the purpose of molecular targeted cells through strong binding capacity between these ligands and cell surface receptors. At the same time, physical and chemistry features of these nanoparticles make them ideal for hyperthermia.For heavy metal nano-particles, whether it can be used in the biomedical field was determined by peak position, number of metal plasmon resonance (surface plasmon resonance, SPR) and surface-enhanced Raman scattering characteristics of the effective spectral range. On the other hand, these features can be regulated by controlling the size and shape of metal nanostructures. Size and shape controlled synthesis has become an important aspect of the study of metal nanoparticles. SPR absorption peak of gold nano ball is below 650 nm which is in the range of biological tissue. Therefore, gold nano ball can not be distinguished from biological tissues when it is used in the body. Therefore, the gold nano ball does not apply for the body in vivo. SPR peak position is relative wide. All of nanoshells, nanorods and nano-cage resonance of these nanoparticles are adjustable. It can be obtained nanoparticles with narrow spectrum by adjusting the proportion of core and shell, nano-rod diameter ratio, or the synthesis of nano-cage geometrical parameters. Three extinction spectra of nanoparticles are between 700-900 nm, near-infrared region. Light absorption and scattering of biological tissues and fluids of this band is the least and light penetration is the best, which are suitable for in vivo use for a specific size of the nano-shell nano-rods and nano-cages. However, harsh reaction conditions are often difficult to obtain the appropriate gold shell, gold cage, which greatly limits its use in practice.Gold nanorod has light and heat effect. And photon of specific laser irradiated on nano-particles can be converted into heat to induce lattice temperature. The thermal energy emitted from these particles can cause damage to target cells to achieve the goal of therapy.The unique chemical and physical properties of gold nanorod and its application in the medical field prospects are interested to our group. The controlled synthesis of gold nanorod is explored early. Synthesis of gold nanorods based on "Seed modulated growth method" that EI-Sayed and so on was improved. Problems of poor reproducibility in the existing response and low reagent utilization were overcomed. High rate of successful synthesis of gold nanorod was obtained and its good appearance was maintained. The requirements that the surface plasmon resonance of gold nanorod was changed with its length diameter ratio were met.Gold Nanorods synthesized using "seed modulation growth" were stabilized in CTAB solution. Because CTAB has a biological toxicity, it is necessary to remove a large number of CTAB in the synthesis process for use in vivo, and to make certain modification to solve the problem of poor biocompatibility. In this study, we made some initial modifications on the synthesized gold nanorods using m-SH-PEG. In order to achieve the function of gold nanorods, it is necessary to connect cell-specific bridging molecules. (Nucleic acid ligands was selected in this study). On this basis,hyperthermia of gold bars on breast cancer and colon cancer cell organelles devices at the cellular level and zoic level was carried out.On this basis, hyperthermia of gold bars on breast cancer and colon cancer cell organelles devices at the cellular level was carried out. Toxicity study of gold nanorods at the cellular level was carried out . the as- modified gold nanorods by m-SH-PEG is evident toxicity. MCF-7 and HT-29 are different sensitivity for laser intensity .The cell damage itself in non-specific adsorption of gold bars on the cells, and cell survival and death threshold in specific binding conditions under different laser intensity were determined by trypan blue staining. The study confirmed feasibility of the theory which provides a realistic basis for hyperthermia in vivo.First of all, a immunodeficient mice transplantation tumor model was established, which formed the basis for the in vivo hyperthermia . Reporter luciferase expression levels was used as a indicator of level of a tumor transplanted in nude mice, hyperthermia effects of intravenous administration, of in situ administration in a nude mouse transplanted with three tumors. Effects of hyperthermia in situ administration were also confirmed by the sizes of three tumors per nude mouse. Hyperthermia results in vivo confirmed the feasibility of theory and provided a realistic basis for further basic research and clinical studies in the future. |
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