IR780 And SiRNA Encapsulated In Biodegradable Nanoparticles For Photothermal And Photodynamic Therapy

Objective To enhance the inhibitory effect of IR780 PTT and PDT on carcinoma MB49 cells in vitro by PLGA NPs carring IR780 and surviving-siRNA.(1)To prepare and characterize IR780-SiRNA-PLGA NPs;(2)To observe the microdeter of IR780-SiRNA-PLGA NPs PTT and PDT for carcinoma MB49 cells in vitro.Methods(1)IR780-siRNA-PLGA NPs were prepared and characterized:IR780-siRNA-PLGA NPs were synthesized using a ultrasound-double emulsion solvent evaporation technique.The preparation parameter were ultrasonic power:360w,ultrasonic time:120s/180s,A Internal water phase:survivin-siRNA 0.5ml dissolved in buffer solution;oil phase:PLGA1mg/ml and IR780 0.2mg dissolved in dichloromethane;external water phase:0.5%PVA buffer solution.The particle size of the nanoparticles was determined by laser particle size analyzer.The morphology of IR780-SiRNA-PLGA NPs was observed by electron microscopy.(2)To observe the microdeter of IR780-SiRNA-PLGA NPs PTT and PDT for carcinoma MB49 cells in vitro:Groups were divided according to the addition of different nano-materials and IR780 dose.MTT assay was used to detect the in vitro killing of MB49 cells by the constructed nanoparticles.Results(1)The optimum preparation process was PLGA concentration of 1mg/ml,ultrasonic power was 360w,and the milk recovery time was 180s.The drug loading rate of IR780 was 1.8%and the diameter was 131nm.The optimal design results showed that the IR780 loading rate was 1.8%and the diameter was 131 nm.The nanoparticles are typical of spherical shape under the electron microscope,and the shape is round and the dispersity is good.(2)The OD value of NPs wrapped with IR780 + siRNA(IR780 dose 5μg/ml)was lower than that of the control group after laser irradiation(P<0.05),the OD value of NPs wrapped IR780 + siRNA(IR780 dose 10μg/ml)was lower than that of the control group(P<0.05),but the decrease of OD value after laser irradiation was more obvious(P<0.01).Conclusion(1)We have successfully constructed IR780-SiRNA-PLGA NPs.The optimized size of the nanoparticles prepared by ultrasonic multi-emulsion method is ideal,and the drug loading can be good and the dispersibility is good.(2)IR780-siRNA-PLGA NPs can reduce the toxicity of IR780 and enhance the photodynamic effect of photodynamic therapy and potothermal therapy on MB49 cells.