Polyethylene Glycol-coated Ultrasmall Superparamagnetic Iron Oxide Nanoparticles-coupled Sialyl Lewis X Nanotheranostic Platform For Nasopharyngeal Carcinoma Imaging And Photothermal Therapy

Objective:In this study,the synthetic polyethylene glycol-coated ultrasmall superparamagnetic iron oxide nanoparticles-coupled sialyl Lewis X(USPIO-PEG-s Le~x)was used as nanothernastic platform for nasopharyngeal carcinoma(NPC).Methods:Five USPIO-PEG-s Le~xnanoparticles with different concentrations of 0mg/ml,0.025mg/ml,0.05mg/ml,0.1mg/ml and 0.2mg/ml were prepared.The different concentrations of USPIO-PEG-s Le~xnanoparticles were irradiated by 808nm wavelengths of near-infrared(NIR)light at different power densities,and their temperature changes were recorded by digital thermometer to detect the photothermal conversion property.Cytotoxicity and Photothermal therapy(PTT)effects in vitro of different concentrations of USPIO-PEG-s Le~xnanoparticles were detected by CCK-8 kit.Nasopharyngeal carcinoma xenograft model was established in nude mice,then USPIO-PEG-s Le~xnanoparticles were injected through the tail vein.Subsequently,Magnetic resonance imaging(MRI)and PTT were performed.The application of USPIO-PEG-s Le~xnanoparticles as nanotheranostic platform in the diagnosis and treatment of nasopharyngeal carcinoma was studied.Results:The USPIO-PEG-s Le~xnanoparticles had excellent photothermal conversion property,and the temperature of USPIO-PEG-s Le~xnanoparticles solution increased with its concentration and power density of NIR on 808nm wavelengths.The biological toxicity results showed that the viability of NPC5-8F cells was related to the concentration of USPIO-PEG-s Le~xnanoparticles and the cultrue time,the difference was statistically significant(P<0.001).The results of PTT in vitro indicated that the viability of 5-8F cells decreased significantly with the concentration of USPIO-PEG-s Le~xnanoparticles increases,the difference was statistically significant(P<0.001),and the viability of NPC5-8F cells were 91.04%±5.20%,77.83%±3.01%,73.48%±5.55%,59.50%±10.98%,17.11%±3.14%,respectively.The T2*values of tumor pre-and post-injection were 30.870±5.604 and 18.335±4.351,respectively,the difference was statistically significant(P<0.001).This implied that the USPIO-PEG-s Le~xnanoparticles could target the tumor area,and reduce the T2*value of tumor tissue.In addition,USPIO-PEG-s Le~xnanoparticles as a photothermal agent for PTT could effectively inhibit tumor progression.The volume change between tail vein injection group,control group and blank group after 5 treatments were 3.04±0.57,5.80±1.06,7.89±2.20,respectively,the difference was statistically significant(P<0.001).Conclusions:Our synthesized USPIO-PEG-s Le~xnanothernastic platform which can be used for MRI and PTT,and it may be become a new strategy for the treatment of NPC.