A kind of multifunctional perfluoropentane (PFP) and ultrasmall Cu2−xS nanodots (u-Cu2−xS NDs) co-incorporated liposome (PFP@ u-Cu2 −xS NDs@liposome) nanocomposite has been facilely and successfully synthesized for enhanced ultrasound/infrared thermal/ photoacoustic multimodal imaging and photothermal therapy upon near infrared (NIR) laser irradiation. Such a liposome-based nanocomposite possesses a number of advantages, such as high dispersity and stability, excellent biocompatibility, small particle size (<100 nm), well-defined core/shell structure, strong NIR absorption and photo-triggered vaporization of PFP, etc. The detailed in vitro investigations demonstrate that the as-synthesized PFP@ u-Cu2−xS NDs@ liposome nanocomposite is capable of enhancing the contrasts of ultrasound/infrared thermal/photoacoustic multimodal imaging, and substantially improving the photothermal therapeutic efficacy. This novel liposome-based theranostic nanoplatform shows great potentials in the future cancer diagnosis and therapy.
INTRODUCTIDNOver the past decades, billions of people have suffered from various cancers worldwide [1]. Fortunately, diverse diagnostic imaging technologies [2-4] and powerful therapeutic methodologies [5][6][7][8][9] have emerged for cancer theranostics. As a minimally invasive and potentially effective therapeutic technique compared with conventional approaches, photothermal therapy (PTT) [10][11][12][13], which utilizes photothermal agents to convert near-infrared (NIR) energy into hyperthermia to kill cancer cells, has receiv ed extensive interest in recent years. Especially, imaging-guided PTT [14][15][16][17] shows great promise in improved efficiency and bio-safety.Currently, ultrasound imaging [18][19][20] is believed to be one of the most widely used imaging tools in the clinic, owing to its considerably high resolution, deep tissue penetration, easy soft tissue recognition and low cost. However, the ultrasound waves are easily disrupted by air or gas and unable to penetrate bones [21]. Infrared thermal imaging [22][23][24] its high imaging speed, sensitivity and convenience, but it suffers from relatively low imaging resolution. Recently, the newly developed photoacoustic imaging [25-28] is emerging as a complementary imaging modality, which combines the high contrast of optical imaging and the high spatial resolution of ultrasound imaging. Therefore, the combination of ultrasound/infrared theramal/photoacoustic imaging techniques will bring unexpected potentials in offering more comprehensive and accurate information with the complementary features of these techniques. In addition, the ingenious strategy of the multimodal imaging-guided PTT will be more powerful and efficient in PTT pre-guidance, intra-monitoring and post-evaluation. Therefore, the exploration of such multifunctional theranostic na noplatforms, which combine both diagnostic and therapeutic functions to allow simultaneous multimodal imaging and therapy as well as the monitoring of tissue/organ's responses to the treatments, h...