Study On The Delivery Of PDT Agents With Triphenylphosphine-modified Magnetic Composite Nanoparticles

With the constantly escalating number of cancer patients worldwide and high mortality from cancer in recent years,cancer has been one of the most serious diseases jeopardizing human health.Photodynamic therapy?PDT?is a new method for cancer diagnosis and treatment through the interaction of light,photosensitizers and oxygen molecules.Due to its unique advantages such as superiority and security compared with the traditional therapy of surgery,radiotherapy and chemotherapy,PDT has been a focus of attention among medical workers and researchers around the world.To further improve the tumor-targeting and biocompatibility of photosensitizer,new drug carrier systems have been synthesized by complex magnetic nanoparticles using R6G as the fluorescent marker in this article,attempting to reach the goal of applying the targeted therapy and fluorescent tracer technique in cancer treatment.Specific work of this thesis reads as follows:1.The magnetic nanocomposites such as Fe₃O₄@SiO₂-APTES-TPP and?Fe₃O₄/R6G?@SiO₂-APTES-TPP were prepared,and then they were characterized by IR spectra,DLS,fluorescence spectrum,XRD,UV-visible spectra,XPS and other methods.2.To get drug-loaded nanocomposites,the complex Pt?DABA-Na??OPDA? was loaded on the surface of the two kinds of magnetic nanocomposites by physical adsorption,respectively.The drug loading capacity was determined by UV spectrophotometry.As a result,the drug loading capacities for Fe₃O₄@SiO₂-APTES-TPP and?Fe₃O₄/R6G?@SiO₂-APTES-TPP were 7.8%and 8.1%,respectively.3.The paper is to investigate the damage effects of the two kinds of magnetic nanocomposites or the corresponding drug-loaded nanocomposites on pBR322 DNA under the dark condition or red light condition by agarose gel electrophoresis.The conclusion was that the magnetic nanocomposites could hardly induce DNA damage no matter with red light or not.The drug-loaded nanocomposites have no obvious damage effect on DNA without light,whereas they could remarkably damage DNA with red light,and the damage effects showed to increase with the increase of their concentration.4.Effects of the various drug-loaded nanocomposites on proliferation of HepG-2 cells were detected by MTT assay.The research indicated that there was no significant effect of the drug-loaded nanocomposites on proliferation without light.However,they could inhibit the growth of HepG-2 cells with red light to some extent,the restraint was increased while increasing the concentration.The study also found that Fe₃O₄@SiO₂-APTES,whose particle sizes were optimized by TMAH,have more significant effect of the proliferation inhibition on tumor cells after drug loading than the unoptimized particles.Furthermore,the triphenylphosphine-modified magnetic nanocomposites have a greater inhibitive effect on cell proliferation than the aminosilane-modified magnetic nanocomposites.