Multifunctional Targeting Of TiO 2 And 2 Nanoparticles In MRI Imaging And Tumor Therapy

Currently, cancer has become the first threat to human health. At present, the main traditional treatment for cancer including surgery, radiotherapy and chemotherapy, these treatments have had some success, but there are also many problems, such as high recurrent, side effects and long recovery time and other limitations. In order to further improve the efficiency of cancer treatment, new treatment techniques including photothermal therapy photodynamic therapy and magnetic heat treatment have been discovered in recent years. Due to the noninvasive or minimally invasive, photothermal therapy in conjunction with high permeability near infrared light, was more and more concerned. Photothermal therapy can make the near-infrared light converting to heat, and the high temperatures can kill the diseased tissue cells. If we combine photothermal therapy with biological targeting small molecules, it can locate diseased cells or tissues accurately rather than normal ones, and it can greatly improve the efficiency of the treatment of tumors. At the same time, the latest designated new drugs carrying chemotherapy drugs transport to the diseased tissue, and then control their release drug slowly. The dosage of chemotherapy drugs can be reduced, and thus can greatly reduce the toxicity for human body. After several years of research and development, multi-modal therapy has become a hot concern. For example, we can combine photothermal therapy with chemotherapy, photothermal therapy combined with photodyssnamic therapy photodynamic therapy and chemotherapy, magnetic heat treatment and photothermal therapy and so on. Comparing to the monotherapy, multi-mode treatment includes advantages of every single-mode, or even have a synergistic effect. It can also improve the effectiveness of cancer treatment. For example photothermal therapy combined with chemotherapy, chemotherapy to reduce the thermal resistance to cancer cells, and then near-infrared light was applied to system.it can effectively kill cancer cells and greatly improve cancer treatment efficiency.In this paper, we have prepared two kinds of nano-particles, one is RGD targeting TiO₂ with near-infrared absorption and the other one is magnetic Fe₅C₂ carrying DOX, and we have also made research on Synergy treatment between DOX release and photothermal therapy and MRI imaging applications of those two kinds of nanoparticles. We have acquired blue oil-soluble TiO₂ nanoparticles with uniform particle size about 10 nm and identical morphology by the method of high-temperature pyrolysis. Then we can get water-soluble TiO₂ nanoparticles with good biocompatibility and stability by DA-N3 ligands exchange get swap and PEG and RGD targeting molecules modified and. In the next study, we will continue to introduce 125 I radio labeled of TiO₂ nanoparticles material and applies it in tumor targeting SPECT imaging, which will greatly enhance tumor diagnosis and treatment efficiency with the integration of diagnosis and cancer treatment.Then we also prepared core-shell structure oil-soluble Fe₅C₂ magnetic nanoparticles with uniform particle size of about 10 nm by the same method of hightemperature pyrolysis. Then we can obtain water-soluble Fe₅C₂ with good stability and biocompatibility by phospholipid modifying. And when those nanoparticles were loaded with DOX, they can achieve synergistic between photothermal therapy and drug delivery. Fe₅C₂-DSPE-mPEG-DOX magnetic nanoparticles material we ultimately obtained, which not only can be used as MRI contrast agents T2 and also be effective synergistic therapeutic drugs and in vitro and in vivo therapeutic due to those high photothermal conversion efficiency and high load capacity of DOX drugs.