Synthesis Of Carbon Nitrides Nanoparticles And Application In Improving The Treatment Of Hypoxia Photodynamics In Tumors

Recently,Photodynamic therapy(PDT)is recognized as an alternative technology for cancer treatment due to its non-invasiveness,low toxicity and controllability.However,the hypoxic tumor microenvironment limits the effectiveness of photodynamic therapy.To overcome this problem,we do the following work to improve the photodynamic therapy of hypoxic tumors.Specifically includes the following three aspects:(1)In the molten salt system,CN nanoparticles(CN NPs)are formed by low-temperature copolymerization.At the same time,the CN NPs have good water solubility and the particle size are less than 100 nm.The experimental results show that the aqueous solution of CN NPs can produce high oxidation activity hydroxyl free radicals(·OH)under white light irradiate.in vivo and in vitro experimental results prove that it can be used for type-? photodynamic therapy and has a better therapeutic effect under hypoxic conditions.(2)Pyromellitic anhydride(PDI)is polymerized onto carbon nitride by low-temperature copolymerization to obtain composite material CN-PDI.Ultrasonic crushing is used to obtain CN-PDI NPs with a particle size of less than 180 nm.Experimental results show that they can produce ·OH under the action of white light and two photons,which can be used as type ? photosensitizers,effectively solving the defects of photodynamic therapy for hypoxic tumors.Meanwhile,two-photon near-infrared light can also increase the penetration depth of the biological tissue.(3)Carbon doped nitride composited(C/CN)by two step copolymerizing,after ultrasonic,the nanoparticles(C/CN NPs)with a particle size of less than200 nm were obtained.Because the absorption is significantly increased,which can be used to realize photoacoustic imaging(I)and near-infrared photodynamic/photothermal treatment under the irradiate of 1064 nm laser to enhance the effect of photodynamic therapy.Besides,photothermal can change blood flow,the increase in speed leads to an increase in the oxygen concentration inside the tumor.Thereby improving the low-oxygen microenvironment of the tumor,and at the same time increasing the tissue penetration ability.