Synthesis Of Metalloporphyrin-polymer Dot And Its Chemiluminesecent Dynamic Therapy

Photodynamic therapy is a cancer treatment with low side effects,which has been widely used in the treatment on esophageal cancer,non-small cell lung cancer,skin cancer and so on.Three elements in the process of photodynamic therapy are required:light at a specific wavelength,oxygen,and photosensitizer.However,the poor tissue penetration of visible light has limited its application in cancer and cancer treatment.In addition,the absorption wavelength of many photosensitizers now with better performance is in the visible light range,which has certain phototoxicity.Chemiluminescent dynamic therapy is a kind of chemiluminescence reaction by catalyzing a light source,activating photosensitizer to produce some reactive oxygen species,so as to achieve the inhibition and killing effect on tumor cells.Compared with photodynamic therapy,chemiluminescent dynamic therapy does not require an outer light source and is expected to be used in the treatment on deep tissue.At present,chemiluminescent dynamic therapy is still in its infancy.Metalloporphyrins usually have strong catalytic activity on chemiluminescence.However,most metalloporphyrins,such as heme,are hydrophobic compounds,and their catalytic properties tend to be dramatically reduced by intense aggregation in biological systems.We have greatly improved the catalytic performance of polymer dots coated with hemin in aqueous solution.This paper is aimed to design and systhesize a water-soluble and non-toxic polymer nanoprobe that is able to catalyze chemiluminescence（CL）with high catalytic efficiency via the selection of various metalloporphyrin catalyst.The probe will be used for catalyzing the chemiluminescence reaction of hydrogen peroxide and luminol as well as its analogues and applied in chemiluminescence dynamic treatment of cancer cells and cancer mice.The main research work includes the following two aspects:（1）The synthesis of 12 metalloporphyrin polymer dots（Pdots）based on nano-coprecipitation to catalyze CL reaction,and selected FeDP-Pdots as a highly efficient catalyst.These Pdots were consist of polystyrene（PS）,amphiphilic compound polystyrene-polyethylene glycol（PS-PEG-COOH）,and different metalloporphyrin.The selective process was divided into two steps.The first step was to synthesize（M-）PPIX-Pdots centered on Co,Fe,Mn,Cu,and then compare the ability five（M-）PPIX-Pdots catalyzing L012-H₂O₂ CL reaction.It was worth noting that Hemin（Fe PPIX）with its obvious advantage was applied into selection in next step.The second step was to select the highest-efficient Fe（Ⅲ）-porphyrin-Pdots as a catalyst functioned in the L012-H₂O₂ CL reaction by changing the external functional groups.As a result,FeDP-Pdots was the one we most wanted among 8 Fe-porphyrin(FeDP,Fe MPPIX,Fe CPPI,Hemin,Fe F₂₀TPP,Fe PPIXDME,Fe TPP,Fe OEC),and it was for further optimization.The particle size,surface charge,catalytic properties and stability of the synthesized polymer dots were characterized respectively.Here,in terms of catalyzing L012-H₂O₂ CL reaction,the CL signal from FeDP-Pdots we synthesized was 175 times higher than Hemin-Pdots in previous work.（2）We found that reactive oxygen species such as singlet oxygen produced by the L012-H₂O₂ effectively inhibit and kill tumor cells.The chemiluminescence system can be used in dynamic therapy.After optimizing the concentration of L012,H₂O₂ and other experimental conditions,we investigated the chemiluminescent dynamic therapy（CLDT）of four types of cancer cells（He La,Mc F-7,U87 MG,H1299）and one normal cell（RAW 264.7）by MTT assay.In addition,FeDP-Pdots were conjugated with c RGD by EDC mediated method,and the formed c RGD-FeDP-Pdots as a nanoprobe was able to target the cancer cells by combined with integrinα_vβ₃ high-expressing tumor cells and normal cell,which will be applied into chemiluminescent dynamic therapy on cells.This CLDT system presented the most effectively killing impact on He La.Also,we made an comparison on CLDT on before and after targeting He La and RAW264.7 cells using FeDP-Pdots and c RGD-FeDP-Pdots.According to the assay result,both these two systems have a strong inhibiting and killing effect on cancer cells.As last,we have successfully performed CLDT experiment on mice model with cervical cancer,with a tumor growth inhibition rate of 80%.Our chemiluminescent dynamic therapy is characterized by the absence of external light source and photosensitizer,which we consider may be used in the treatment of deep cancer tissues in the future.