Study On The Photodynamic Activity Of Platinum Diimine Complexes Modified With Different Functional Groups

Cancer has become one of the most serious diseases to human life and health.Therefore,it is urgent to seek a safe and effective cancer treatment to solve this problem through a scientific method.Photodynamic therapy?PDT?becomes a new treatment of cancer for its advantages in selectivity collaborative and repeatability and lower side effects.Photodynamic reaction refers to the photosensitive drugs when irradiated with red lightwould produce reactive oxygen species to cause cell damage and necrosis.Photodynamic therapy is the application of photodynamic reaction for the treatment of disease in the field of biology and medicine.Thus,the use of photodynamic therapy as a cancer therapy isparticularly attractive,and photodynamic therapy has become the mainsubject of intens ive investigation in recent years.Platinum diimine complexes can be used as photosensitizer of photodynamic therapy for the flat structure,maximum absorption at near-infrared light,stable phys icochemical properties under the dark condition,and ability to generate singlet oxygen irradiated with red light can be used as photosensitizer of photodynamic therapy.Structural modification of the ligand is expected to further improve the photodynamic activity of the platinum complexes and make its maximum absorption wavelength redshift.The magnetic composite nanoparticles of surface modification as drug carrier can improve targeting property and biocompatibility of photosensitizer.In this thesis,a series of platinum diimine complexes were synthes ized after a large number of literature research,and their capability to generate singlet oxygen were studied.Then these complexes were loaded on two magnetic nanocomposite particles with good biological compatibility.The interaction of drug-loading nanopartic les and DNA were further studied.l.Pt?4-Br-OPDI?₂ and Pt?DIBA-Na??OPDI?were synthes ized and charactrized by UV-vis spectroscopy and elemental analysis.2.Employing chemical capture method with DPBF as a fluorescent probe studied the photodynamic activity of the complexes.The results indicated that Pt?4-Br-OPDI?₂ has better capability to generate singlet oxygen when irradiated with red light.3.Pt?4-Br-OPDI?₂ and Pt?DIBA-Na??OPDI?were loaded on the surface modified magnetic nanopartic les?Fe₃O₄/TA?@Si O₂ and Fe₃O₄@Si O₂-APTES respectively by the method of physical adsorption.the drug-loading capability of drug-loading nanopartic les was determined by ultraviolet-visible spectrometry.Results show that the drug-loading rate of the magnetic nanoparticles?Fe₃O₄/TA?@Si O₂ and Fe₃O₄@Si O₂-APTES loading on Pt?4-Br-OPDI?₂ were 6.8%and 4.5%respectively.And the drug-loading rate of the magnetic nanoparticles?Fe₃O₄/TA?@Si O₂ and Fe₃O₄@Si O₂-APTES loading on Pt?DIBA-Na??OPDI?were 7.6%and 5.3%respectively.4.The interactions of the complexes and drug-loading nanoparticles with DNA were studied by agarose gel electrophoresis.Studies have shown that complexes irradiated with red light show obvious cleavage of DNA,and drug-loading nanoparticles irradiated with red light also damage DNA.The interactions of the complexes and photosensitizer-loaded magnetic composite nanoparticles with p BR322 DNA were weak without red light.5.MTT colorimetric method was used to study the interaction of the photosensitizers and SMMC-7721 cells.Pt?4-Br-OPDI?₂ has certain degree of inhibition to the cancer cell proliferation in the presence of illumination conditions.