| Objective: To investigate the preparation of a new photosensitizer(PpIX-IR-820@Lipo NPs)by liposome loaded protoporphyrin(PpIX)and new indocyanine green(IR-820).Then to study its fluorescence labeling and promoting apoptosis in He La cells.Methods: PpIX and IR-820 were loaded into liposomes by the hydration film method to obtain PpIX-IR-820@Lipo NPs.The morphology,size and dispersion were observed by transmission electron microscope(TEM),scanning electron microscope(SEM)and Malvern particle size/potential meter.The drug encapsulation efficiency,drug loading efficiency,stability,generation of reactive oxygen species(ROS)and photothermal heating of PpIX-IR-820@Lipo NPs were studied by UV-Vis,fluorescence spectrophotometer and thermal imager temperature measurements.The toxicity and fluorescence labeling cells and photodynamic-photothermal synergism of PpIX-IR-820@Lipo NPs on He La cells were determined by Cell Counting Kit-8 method,laser scanning confocal fluorescence imaging,ROS fluorescence imaging experiment,cell apoptosis fluorescence imaging experiment and flow cytometry assay.Results: The SEM and TEM shows that PpIX-IR-820@Lipo NPs are spherical particle about 380 nm.It has good solution stability(89.93%)and fluorescence stability(93.92%),and fluorescence peaks(659 and 843 nm)in the near-infrared spectrum.The entrapment efficiency of PpIX and IR-820 is 92% and 27.11%,the drug loading rate is13.14% and 3.8%,and the photothermal conversion efficiency is 25.23%.Under laser irradiation,PpIX-IR-820@Lipo NPs provided higher ROS generation rate(78.9% vs.30.7%);exhibited higher temperature elevation of photoconversion(32.6℃ vs.26.3℃).The low biological toxicity of PpIX-IR-820@Lipo NPs on He La and H8 cells(93.1% and96.3%).The phototoxicity was significantly enhanced when double laser irradiation was added(92.6% vs.38.3%),50μg/m L is the optimal safe concentration of PpIX-IR-820@Lipo NPs for He La cell intervention.In addition,PpIX-IR-820@Lipo NPs showed effective uptake in both He La and A549 cells.Under 450 nm and 793 nm laser irradiation,ROS fluorescence and apoptotic cell fluorescence were observed by DCFH-DA and Annexin VFITC.The results of flow cytometry concluded that laser irradiation caused less damage to cells(11.68% vs.11.10%);The dual laser irradiation ingested He La cells were more apoptotic with PpIX-IR-820@Lipo NPs(70.5% vs.11.68%).Conclusion: The PpIX-IR-820@Lipo NPs designed and prepared has nanometer size,labeled He La cells under laser irradiation and effectively inhibited cell proliferation,which may serve as a new choice for photodynamic-photothermal(PDT-PTT)synergistic therapy for cervical cancer. |
