Construction And Application Of A New Optical Nano-diagnosis And Treatment System

The single treatment of cancer cannot completely eliminate tumors and inhibit the metastasis of cancer cells,and long-term use of anti-cancer drugs will cause drug resistance,which leads to the gradual failure of chemotherapy in later treatment.In order to overcome this obstacle,multimodal imaging-guided combined diagnosis and treatment has become an effective treatment.At present,photodynamic therapy(PDT)is a clinically recognized minimally invasive phototherapy,which has been used in the treatment of cancer.Under the excitation of light of a specific wavelength,the photosensitizer can activate the generation of reactive oxygen species that can kill cancer cells,thereby achieving specific treatment at the tumor,and with little side effects.At the same time,photothermal therapy(PTT),as an innovative non-invasive tumor treatment method,can also overcome some of the limitations of photodynamic therapy,through the heat of the photothermal conversion agent at the tumor to reach the heat of the tumor cells Ablation,thereby effectively improving the effectiveness of cancer treatment.The current biological imaging technology can provide detailed visual information of various biological entities with unprecedented clarity,and monitor various physiological and pathological processes in real time.Near infrared second zone(NIR-II,1000-1700 nm)Due to its imaging quality and sensitivity and high imaging depth,it is increasingly widely used.Compared with traditional imaging methods NIR-II fluorescence imaging has many advantages such as low imaging cost,simple operation,wide range and high selectivity.As an emerging imaging technology,photoacoustic imaging(PAI)has high ultrasound resolution and powerful light absorption contrast,which can overcome the depth limitations of resolution and conventional fluorescence imaging technology.PAI can further provide 3D images of tumor tissue with high selectivity and deep penetration to obtain high-resolution images in pre-clinical and clinical applications.Therefore,it has considerable application potential in the accurate positioning and treatment of tumors.Based on pyrrolopyrrole dione(DPP),this paper constructs two new types of photo-nano diagnosis and treatment systems,combined with the guidance of near-infrared two-region NIR-II fluorescence imaging and photoacoustic imaging,and can carry out the combined research of photothermal and photodynamic therapy.(1)In this paper,a nano-diagnosis and treatment system(DPP-BDT NPs)with photothermal and photodynamic properties is constructed with a new type of small organic molecules based on DPP.DPP-BDT NPs are prepared by simple nanoprecipitation method.The resulting nanoparticles have good water solubility,good absorption in the near infrared region,and fluorescence emission at 1000 nm.DPP-BDT NPs also have good photothermal and photodynamic properties,and can be combined with photodynamic and photothermal therapy under the guidance of near infrared two-region NIR-II fluorescence imaging and photoacoustic imaging.(2)In this paper,a nano-diagnostic and therapeutic system(DPP-BN NPs)with photothermal and photodynamic properties is constructed with a new polymer based on DPP.DPP-BN NPs are prepared by a simple nano-precipitation method.The obtained nanoparticles have good absorption in the near infrared region,and NIR-II fluorescence emission at 1000 nm,as well as good biocompatibility and excellent optical stability.Under 660 nm laser irradiation,it has a good cancer cell killing effect,can achieve the effect of efficient photothermal / photodynamic therapy,and has a good tumor diagnosis and treatment prospect.