Rational Design of IR820‐ and Ce6‐Based Versatile Micelle for Single NIR Laser–Induced Imaging and Dual‐Modal Phototherapy

Abstract

triggered by near-infrared (NIR) lightexcited photothermal agents [10] while PDT causes the cell death by photosensitizers generating highly cytotoxic reactive oxygen species (ROS) upon light excitation. [11][12][13] With distinct mechanisms of action, the integration of PTT and PDT into one nanoplatform holds great potential to achieve highly efficient cancer therapy. [14][15][16] However, in such combined therapy, two different excitation wavelengths are usually required for the activation of PTT and PDT, [17][18][19] leading to complicated treatment process and prolonged therapeutic time. Thus, it is highly desirable to design a nanoplatform with single NIR light-induced phototherapy.Although strategies of single-wavelength NIR light-mediated PTT/PDT combination therapy have been reported, photothermal agents commonly used in combined systems are inorganic nanomaterials, like gold nanostructures, [20][21][22] MoS 2 nanosheets, [23] black phosphorus nanosheets, [24] and black titania, [25] which show tedious preparation process, poor degradation, difficult excretion, and potential long-term toxicity. NIR organic dyes, which possess unique advantages of outstanding biodegradability and biocompatibility in contrast with inorganic photothermal agents, will be ideal alternatives. Especially, for new indocyanine green (IR820), a structural analog of indocyanine green (ICG), which has been approved by the Food and Drug Administration (FDA) in clinical use, [26][27][28] holds the suitable fluorescence, strong absorption in NIR region, and efficient light-thermal conversion. [29,30] Additionally, it is more stable and easily modified due to the meso-halogen in its chemical structure. Unfortunately, it differs from organic photodynamic agents in intrinsic excitation wavelength, bringing a great challenge to achieve single NIR laser-induced combinational phototherapy. Moreover, it suffers from short half-life in blood, rapid clearance from the body, and lack of specificity to target tumor area. [31,32] Chlorin e6 (Ce6), an FDA-approved second-generation photosensitizer, [33] is extensively used in PDT on account of its high singlet oxygen generation efficiency, [34] near-infrared light excitation allowing deep tissue penetration, and fluorescence imaging capability. [35,36] Despite these upsides, Ce6 has shortcomings including poor water solubility and nonspecific accumulation in tumor sites, [37] which largely compromise Phototherapy as a promising cancer diagnostic and therapeutic strategy has aroused extensive attention. However, single-wavelength near-infrared (NIR) light-triggered combinational treatment of photothermal therapy (PTT) and photodynamic therapy (PDT) is still a great challenge. Herein, a multifunctional micelle activated by a single-wavelength laser for simultaneous PTT and PDT as well as fluorescence imaging is developed. Briefly, new indocyanine green (IR820) is conjugated to d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) via the linker 6-aminocaproic acid, and then, chlorin e6 (Ce6) is enc...

An IR820 Dye–Protein Complex for Second Near‐Infrared Window and Photoacoustic Imaging

“…IR820 has been used to label polyethylenimine on delivered DNA so that the labeled construct can be monitored in vivo with noninvasive NIR‐I imaging . Studies on IR820 and IR820‐labeled bioconjugates have clearly confirmed its value and prospects in NIR‐I imaging and image‐guided drug or photothermal therapy . An IR820‐based agent was recently designed for naked‐eye and NIR I fluorescence dual‐mode imaging…”

Prototypic Heptamethine Cyanine Incorporating Nanomaterials for Cancer Phototheragnostic

“…The application of nanoparticles incorporating IR820 in cancer PTT/PDT and NIR imaging and PAI has also been extensively investigated ( Tables 6 and ) . For instance, Huang et al incorporated IR820 in ferritin nanocages, demonstrating the ability of these nanostructures to accumulate at the tumor and image it through PAI .…”

A review on herbal drug loaded into pharmaceutical carrier techniques and its evaluation process

“…11. Micelle carrier, the stable micelles, may exhibit improved photothermal efficiency toward cancer cells for both in vitro and in vivo studies [15].…”