MoS₂ Quantum Dots Loaded Multifunctional Theragnostic Agent For US/CT Imaging And Photothermal Therapy

Objective To fabricate the high-performance theragnostic nanocapsules,molybdenum disulfide quantum dots（MoS₂ QDs）-shelled perfluorohexanes（PFH）nanocapsules with PLLAylation（PFH@PLLA-MoS₂）was synthesized,which can be served as ultrasound（US）and Computed Tomography（CT）contrast agent and simultaneously applied in photothermal therapy.Furthermore,dual-modal imaging and photothermal capacity were evaluated in vitro and in vivo.Methods PFH@PLLA-MoS₂ nanocapsules were fabricated by the oil-in-water emulsion method.Morphology,diameter and potentials of PFH@PLLA-MoS₂ were evaluated by different methods.Subsequently,capacity of phase transformation,photothermal effect and US/CT imaging were measured in vitro and in vivo.Results The PFH@PLLA-MoS₂ nanocapsules were spherical with the diameter of 205.1±67.3nm,and the average potentials was+0.76mV.The nanocapsules could be absorbed by MDA-MB-231 cells,blue fluorescence was observed within breast cancer cells under a laser scanning confocal microscopy at the excitation wavelength of 405 nm.PFH@PLLA-MoS₂ could transform energy from the light into heat under laser illumination,caused by the temperature of solution rising up to about 58℃in 20 min.The nanocapsules enlarged as temperature went up and fractured at 70℃.MTT assay indicated that PFH@PLLA-MoS₂ has low cytotoxicity,however,it could induce apoptosis under laser irradiation.Furthermore,the MDA-MB-231 Subcutaneous Xenograft Mouse Models were built,in vivo experiments were proceeded when the tumor grew up to 100-200 mm³.PFH@PLLA-MoS₂ exhibited excellent ultrasound imaging capacity in vivo.H&E and TUNEL assay showed PFH@PLLA-MoS₂ had admirable photothermal killing effect under the combination of ultrasound and laser irradiation（apoptotic rate is 68.3%）.Conclusion The PFH@PLLA-MoS₂ theragnostic agent has been successfully synthesized,it is a promising agent for dual-modal US/CT imaging and in situ photothermal treatment.