| Malignant tumor is serious harm to human health cancer, people called it a "plague of the 20th century." Cancer has become the number one killer of urban residents in China, second only to heart disease, cerebrovascular disease mortality caused. A recent UK study shows that in the next 40 years, the chances of human cancer, especially malignant tumor to double in the treatment of advanced cancer, the current through surgery, radiotherapy, chemotherapy, three means there has been a significant limitation , surgery, radiation therapy can not solve the problem of tumor cells in systemic metastasis, chemotherapy, although the effect rapidly, but can easily result in systemic toxicity.Hyperthermia has been following the surgery, radiotherapy and chemotherapy treatment of cancer after a new method, the basic principle is to use physical energy heating the tumor tissue temperature to rise to the effective treatment temperature (41-47℃), and to maintain a certain time, the use of normal tissue and tumor cell tolerance to temperature differences, in order to achieve both the tumor cells, without damage to normal tissue for therapeutic purposes. Hyperthermia on tumor cells not only have a direct cytotoxic effect, but also can enhance chemotherapy, radiation therapy, improve immunity, suppression and prevention of cancer recurrence and metastasis.However, in recent years with the development of nanotechnology, cancer treatment toward a more rational and more effective direction comprehensive treatment, including application of nanotechnology development with the overall treatment time plays an increasingly important position. The results show that gold nanoparticles have a strong in the near infrared region of light absorption, near infrared (800-1200 nm) is the transmission window of normal tissue, near infrared laser on the human body damage is minimal. Gold nanoparticles by near-infrared laser irradiation, metal nano-materials will absorb the light energy into heat, prompting local temperature within the range to kill tumor cells for therapeutic purposes. This technique can not be completely avoided surgery to remove the tumor and chemotherapy resistance aroused by such shortcomings, these advantages in the biomedical field it has a wide application prospect.In this study, gold nanoparticles were synthesized rod material, and gold nanoparticles inhibits tumor hyperthermia infrared determination of cell growth and targeting infrared hyperthermia were studied.1 Seed growth method using the PEG modification of the successful synthesis of two kinds of nano materials, gold nanorods, and further modified gold nanoparticles targeting rods. nanorods are about to 40nm, a width of 12nm. The above two materials are strong infrared absorption and good stability.2 MTT colorimetric assay on PEG modified gold nanorods HepG2, BC-37, A-549, Hela cell toxicity, the results shown in HepG2 cells on gold nanorods in 21.25μM, on the BC-37 and A-549 cells were In 28.3μM, on Hela cells in 42.5μM concentrations compared with the control group no significant difference in the cell is non-toxic, is the appropriate role of concentration. The targeting peptide modified gold nanoparticles on the rods on HepG2 cells in 5.31μM this is non-toxic concentrations, is the appropriate role of concentration.3 PEG modification of the gold nanorod infrared hyperthermia effect on HepG2, BC-37, A-549, Hela cells, by cell viability test results show that gold nanoparticles infrared hyperthermia inhibited tumor cell proliferation, cell death rate was over 90%.Under an inverted microscope and cell morphology was observed after staining showed that the appropriate exposure conditions, the infrared hyperthermia the cells became round and the cytoplasm less contact with the surrounding cell disruption and cell adhesion reduce the features of apoptosis may occur.4 Targeting peptide modified gold nanoparticles by infrared hyperthermia rod HepG2 hepatoma cells and normal liver cells HL7702, through MTT test showed that gold nanoparticles could inhibit the above two kinds of infrared hyperthermia cell proliferation, and the inhibition of power and infrared radiation was dependent relationship, with the irradiation power increases, cell viability decreased. The results show that the thermal sensitivity of HepG2 hepatoma cells was significantly higher than normal liver cells HL7702. Then modified gold nanoparticles targeting peptide rods on liver cancer cells HepG2, normal liver cells and Hela cells HL7702 infrared hyperthermia, experimental results show that the power 15W/cm2 on HepG2 cells was significantly inhibited, the inhibition rate of 90 %, while on HL7702 cells, Hela cells did not show significant inhibition, and the targeting peptide is not connected in the power of nano-gold bars under the infrared irradiation inhibition of HepG2 cells less than 5%.5 Through the tail vein injection of different concentrations of PEG-nanorod measured obtaining the LD50 in mice was 0.71mg/kg.This experiment, mice injected with the concentration will not lead to death.WP05 modified nanorods were verified in vivo targeting, the effect was that gold nanoparticles modified infrared targeting tumor hyperthermia in the shows to a good prospect.In summary, we successfully synthesized modified peptides in PEG and targeting materials, nano-gold bars, the two materials are strong infrared absorption and good stability, and its hydrosol also has good stability, their cell toxicity, has good biocompatibility and so on. And its inhibition of cell growth were determined, the results showed that gold nanoparticles infrared hyperthermia inhibited the growth of tumor cells, the maximum inhibition rate of 90% or more. Targeting Infrared hyperthermia and in vitro carried out a preliminary study. Therefore, this study may be cancer and other solid tumors provides a new way to targeted therapy. For later preparation of nano-materials, nano-particle surface modification of materials selection of molecular, nano-materials, the residue after treatment and the impact on normal tissue provides a theoretical basis for the gold nanoparticles infrared hyperthermia treatment of cancer clinical research a new idea.
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