Study Of Multimodal Imaging And Cell Damage Effects Of Rheumatoid Arthritis Synovitis In Vitro With Phase-change Nanoparticles Loaded With Methotrexate And IR820

Rheumatoid arthritis(Rheumatoid arthritis,RA)is a common autoimmune disease with unknown etiology.The initial pathological changes are manifested by the continuous proliferation of fibroid synovial cells and macrophages,increased secretion of diseased arthritic factors,and a large number of new blood vessels.The principle of photodynamic therapy is that a certain photosensitizer produces reactive oxygen species after being irradiated by a laser of a specific wavelength,which can kill and promote the apoptosis of FLSs.The purpose of this experiment is to compare the pharmacological characteristics and ultrasonic/photoacoustic dual-mode imaging characteristics of two phase-change nano-drug delivery systems in vitro,Secondly,to explore the photodynamic effect of phase-change multifunctional molecular imaging probe containing IR820 and perfluoropentane(PFP)on rheumatoid arthritis fibroblast-like synovial cells.Two phase-change nanoparticles of MTX/ICG/PFP/NPs and IR820/PFP/NPs were prepared by double emulsification method,and their basic characterization,thermally induced phase change and photothermal effect were detected.Observe the dual-mode ultrasound/photoacoustic imaging capabilities of two kinds of nanoparticles in vitro;To evaluate the in vitro reactive oxygen generation of phase-change multifunctional molecular imaging probe(IR820/PFP@PLGA),CCK-8 method and flow cytometry were used to observe the photodynamic therapy effect of the nanoparticles on fibroblast-like synovial cells.The experimental study found:(1)In this experiment,MTX/ICG/PFP/NPs and IR820/PFP/NPs were successfully prepared,the particle sizes were respectively(261.8±3.2)nm、(229.1±5.17)nm,The potentials are(-27.4±0.7)m V、(-19.56±0.87)m VIt,can be seen from the microscope that the nanoparticles are spherical with relatively uniform size and morphology,and their dispersion is good.Transmission electron microscopy showed that the nanoparticles were formed into round black spheres.(2)By irradiating nanoparticles with different concentrations with 808 nm laser,it can be seen that the temperature of IR820/PFP/PLGA nanoparticles after laser irradiation increases the highest with the increase of their concentration.It can reach above 50℃,among which MTX/ICG/PFP/NPs group and IR820/PFP/NPs group showed similar temperature increase.(3)By comparing the stability and ultrasound and photoacoustic imaging effects of PLGA nanoparticles containing IR820 and ICG,it is found that PLGA nanoparticles containing IR820 have better photoacoustic imaging effects and are more stable and multifunctional nanoparticles.(4)The singlet fluorescence(SOSG)method detects that the nanoparticles produce a large amount of active oxygen after laser irradiation and are irradiated time-dependent.In vitro cell experiments found that nanoparticles have good biological safety,and the cytotoxicity increases with the concentration of nanoparticles after laser irradiation.At the same time,the apoptosis rate of nanoparticles after laser irradiation is also significantly higher(40.66%).In summary,the multifunctional nanoparticle IR820/PFP/NPs can promote the phase transition of PFP based on the photothermal conversion performance of IR820,endow the nano-platform with ultrasound imaging capabilities,and realize visual monitoring in diagnosis and treatment.In addition,IR820 has photoacoustic imaging performance and photodynamic therapy performance.Therefore,this multi-functional multi-modal nano-platform has dual-modality imaging and photodynamic therapy(PDT)functions for rheumatoid arthritis,and is expected to realize the integration of diagnosis and treatment in the clinic.