Recently, SXH and SDH NIR-II SMDPs are synthesized for integrin αVβ3targeted glioma imaging, which not only enable to delineate tumors from surrounding normal tissue but in image-guided surgery [17]. CQS1000 is a multifunctional
NIR-II probe by encapsulating CH1055 into phospholipid vesicles (Fig. 5a–c)
[16]. CQS1000 can visualize and monitor many physiological and pathological
conditions of circulatory systems in noninvasive and dynamical, including drainage
and routing lymphatic, tumor angiogenesis and vascular diseases. In sentinel lymph
node mapping, CQS1000 offers particular promise in guidance surgery. In addition,
by distinguishing the blood supply and lymphatic drainage, this new NIR-II
fluorophore allowed precise resection of tumors, which may lead to better survival
and reduced relapse rates. Using click chemistry, a novel water-soluble NIR-II
SMDC, IR-FGP, is synthesized recently by Zhu et al. [14] IR-FGP not only obtains
a bright NIR-II emission by tuning a D–A–D architecture systematically but also
offers many targeting channels. In addition, this IR-FGP NIR-II SMDC nanoprobe
allows 3D tomographic imaging in deep tissue and reduces the autofluorescence
(Fig. 5d–f). Moreover, this facilitated 3D imaging brain tissue sections demonstrate
multicolor molecular imaging across both the NIR-I and NIR-II windows
(800–1,700 nm).
Nanoprecipitation method has been used to synthesize donor–acceptor
chromophore-based nanoparticle (DAP) by encapsulating the NIR-II chromophore
CH1000 molecules within amphiphilic phospholipids [35]. To enhance tumortargeting efficiency, the EGFR affibody is conjugated with DAP successfully. This
affibody–DAP organic nanoprobe demonstrates capability to selectively target
EGFR-positive tumors in an FTC-133 subcutaneous mouse model with enormous
enhanced PAI and NIR-II fluorescence contrast in both in vitro and in vivo (Fig. 6a–
e). In a novel PET/NIR-II dual-modal imaging platform,
68 Ga-SCH2 is developed
using base-catalyzed, highly efficient, and selective assembly method recently
[13]. This small-molecule-based PET/NIR-II probe can be successfully used for
αVβ3-targeted tumor imaging. The excellent NIR-II and PET dual-modal imaging
properties such as high signal to background ratio and specificity lead to tumor-free
resection in the small animal models. These inspiring results show high potential for
tumor surgery and translational clinical.
Very recently, a small-molecule NIR-II fluorophore FD-1080 with both excitation and emission in the NIR-II region has been successfully synthesized for in vivo
imaging. In this novel structure, a heptamethine structure is designed to shift the
absorption and emission into NIR-II region. Sulphonic and cyclohexene groups are
introduced to enhance its water solubility and stability. The quantum yield of
FD-1080 can be increased from 0.31 to 5.94% after combining with FBS. Significantly, 1,064 nm NIR-II excitation was demonstrated with the high tissue penetration depth and superior imaging resolution compared to previously reported NIR
excitation from 650 to 980 nm. FD-1080 not only is capable of realizing noninvasive
high-resolution deep-tissue hindlimb vasculature and brain vessel bioimaging but
also quantifies the respiratory rate based on the dynamic imaging of respiratory
craniocaudal motion of the liver for the awake and anaesthetized mouse [36] (Fig. 7).
Advancements of Second Near-Infrared Biological Window Fluorophores:. . .
89
NIR-II probe by encapsulating CH1055 into phospholipid vesicles (Fig. 5a–c)
[16]. CQS1000 can visualize and monitor many physiological and pathological
conditions of circulatory systems in noninvasive and dynamical, including drainage
and routing lymphatic, tumor angiogenesis and vascular diseases. In sentinel lymph
node mapping, CQS1000 offers particular promise in guidance surgery. In addition,
by distinguishing the blood supply and lymphatic drainage, this new NIR-II
fluorophore allowed precise resection of tumors, which may lead to better survival
and reduced relapse rates. Using click chemistry, a novel water-soluble NIR-II
SMDC, IR-FGP, is synthesized recently by Zhu et al. [14] IR-FGP not only obtains
a bright NIR-II emission by tuning a D–A–D architecture systematically but also
offers many targeting channels. In addition, this IR-FGP NIR-II SMDC nanoprobe
allows 3D tomographic imaging in deep tissue and reduces the autofluorescence
(Fig. 5d–f). Moreover, this facilitated 3D imaging brain tissue sections demonstrate
multicolor molecular imaging across both the NIR-I and NIR-II windows
(800–1,700 nm).
Nanoprecipitation method has been used to synthesize donor–acceptor
chromophore-based nanoparticle (DAP) by encapsulating the NIR-II chromophore
CH1000 molecules within amphiphilic phospholipids [35]. To enhance tumortargeting efficiency, the EGFR affibody is conjugated with DAP successfully. This
affibody–DAP organic nanoprobe demonstrates capability to selectively target
EGFR-positive tumors in an FTC-133 subcutaneous mouse model with enormous
enhanced PAI and NIR-II fluorescence contrast in both in vitro and in vivo (Fig. 6a–
e). In a novel PET/NIR-II dual-modal imaging platform,
68 Ga-SCH2 is developed
using base-catalyzed, highly efficient, and selective assembly method recently
[13]. This small-molecule-based PET/NIR-II probe can be successfully used for
αVβ3-targeted tumor imaging. The excellent NIR-II and PET dual-modal imaging
properties such as high signal to background ratio and specificity lead to tumor-free
resection in the small animal models. These inspiring results show high potential for
tumor surgery and translational clinical.
Very recently, a small-molecule NIR-II fluorophore FD-1080 with both excitation and emission in the NIR-II region has been successfully synthesized for in vivo
imaging. In this novel structure, a heptamethine structure is designed to shift the
absorption and emission into NIR-II region. Sulphonic and cyclohexene groups are
introduced to enhance its water solubility and stability. The quantum yield of
FD-1080 can be increased from 0.31 to 5.94% after combining with FBS. Significantly, 1,064 nm NIR-II excitation was demonstrated with the high tissue penetration depth and superior imaging resolution compared to previously reported NIR
excitation from 650 to 980 nm. FD-1080 not only is capable of realizing noninvasive
high-resolution deep-tissue hindlimb vasculature and brain vessel bioimaging but
also quantifies the respiratory rate based on the dynamic imaging of respiratory
craniocaudal motion of the liver for the awake and anaesthetized mouse [36] (Fig. 7).
Advancements of Second Near-Infrared Biological Window Fluorophores:. . .
89