【Biomaterials】华中科技大学朱锦涛等|4倍亮度提升与11.1超高肿瘤对比度：仿生超分子工程赋能膀胱癌近红外二区精准手术导航#

Scheme 1. Schematic illustration of the assembly and targeting design of NIR-II fluorescent probes for imaging applications. (a) Light-harvesting complex (LHCs) in plant photosynthesis and molecular design of LHCs-mimetic NIR-II nanoprobe. (b) Bio-inspired supramolecular assembly and cooperative supramolecular dual targeting of CMPI. (c) The high-contrast NIR-II imaging and surgical navigation of CMPI for bladder cancer.#

Fig. 1. Characterization of CMPI. (a) Photographs of vials with carriers and probes in aqueous solutions. TEM images of (b) CI and (c) CMPI. (d) Hydrodynamic sizes of β-CMP and CMPI. (e) Zeta potential of β-CMP and CMPI. (f) Hydrodynamic size and polydispersity index (PDI) of CMPI in water, PBS, and 10% serum during 5-day storage at 4 °C. (g) Absorption spectra (ICG = 20 μM). (h) NIR-II quantum yields (NIR-II QYs) of free ICG, CI, and CMPI from 900 to 1500 nm. (i) Fluorescence spectra (ICG = 20 μM, Ex = 740 nm), (j) NIR-II tail emission spectra (ICG = 20 μM, Ex = 808 nm). (k) NIR-II fluorescence images and (l) quantitative analysis at a 1100 nm long-pass filter (ICG = 20 μM). Laser: 808 nm, 75 mW cm−2, exposure time: 50 ms.#

Fig. 2. Supramolecular assembly mechanism of CMPI. (a) Molecular dynamics simulation of CMPI from 0 to 100 ns. Golden and blue, respectively, represent β-CD and the other atoms in β-CMP. Green represents ICG. (b) Snapshots of the host-guest assembly processes between β-CMP and ICG. (c) Spatial confinement of ICG by β-CMP. (d) Effect of Adol, NaCl, and urea on the emission spectra of CMPI. (e) Isothermal titration calorimetry (ITC) data for the interaction between ICG and β-CMP at 298 K. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)#

Fig. 3. pH-induced aggregation and enhanced targeting of CMPI. (a) Schematic illustration of the cooperative supramolecular dual-targeting mechanism of CMPI. (b) Confocal laser scanning microscopy (CLSM) and (c) flow cytometry of M2-like macrophages incubated with free ICG, CI, CMPI, and M2pep + CMPI (excess M2pep pre-added) for 6 h at pH 7.2 or 6.0. Blue represents the nucleus stained with Hoechst. Red represents ICG in the cytoplasm. (d) TEM image of CMPI after incubation at pH 6.0 for 2 h. (e) Hydrodynamic size variation of CMPI after incubation for 8 h at pH 6.0. (f) Zeta potential variation of CMPI after incubation for 8 h at pH 7.2 or 6.0. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)#

在体内生物学行为方面，该纳米探针展现出独特的微环境响应性动态靶向能力。当复合物随血液循环递送至呈微酸性的膀胱肿瘤微环境时，酸敏感基团发生水解，驱动探针表面电荷快速发生由负转正的逆转并在原位组装成更大的超分子聚集体。这种物理形态的转变与M2pep多肽对膀胱癌中大量存在的M2型肿瘤相关巨噬细胞表面CD206受体的特异性识别相结合，建立了高效的协同双靶向机制。在小鼠皮下、原位及肺转移膀胱癌模型中，该探针在给药48小时后实现了高达11.1的肿瘤与正常组织对比度，不仅能清晰勾勒出清晰的手术切除边缘，还成功识别出直径小于1毫米的超微小转移灶。

Fig. 4. Enhanced NIR-II imaging in subcutaneous bladder tumors with CMPI. (a) NIR-II fluorescence images of subcutaneous bladder tumors bearing mice (dorsal view) at a 1100 nm long-pass filter after i.v. injection with free ICG, CI, CMI, and CMPI (ICG = 0.2 mM, 0.1 mL). Laser: 808 nm, 75 mW cm−2, exposure time: 300 ms. The white dashed arrow presents the tumor region. (b) Ex vivo NIR-II imaging and (c) quantitative analysis of major organs (e.g., heart, liver, spleen, lung, kidney) and the tumors of the above mice sacrificed at 48 h post-injection. Laser: 808 nm, 1100 nm long-pass filter, 75 mW cm−2, exposure time: 100 ms. (d) Tumor-to-liver ratio according to panel (b). (e) Tumor-to-kidney ratio according to panel (b). ns, not significant, ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001. The results are represented of n = 3 independent experiments. Data are presented as mean values ± SD.#

Fig. 5. High spatial resolution NIR-II imaging of CMPI in orthotopic bladder tumors. (a) Schematic illustration of orthotopic bladder tumor imaging. (b) Bioluminescence and NIR-II fluorescence images of orthotopic bladder tumors bearing mice (supine view) at a 900 nm long-pass filter after i.v. injection with free ICG and CMPI (ICG = 0.2 mM, 0.1 mL). Laser: 808 nm, 75 mW cm−2, exposure time: 100 ms. (c) The enlargement of NIR-II imaging and surgery of mice from panel (b). (d) A cross-sectional fluorescence intensity plot profile (dots) and Gaussian fit (red line) along the white dashed line 1 in panel (c). (e) Ex vivo NIR-II imaging of the bladder in panel (b). Laser: 808 nm, 900 nm long-pass filter, 75 mW cm−2, exposure time: 20 ms. (f) HE staining of the excised orthotopic bladder tumor. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)#

Fig. 6. High-contrast NIR-II imaging in lung metastatic tumor for CMPI. (a) Schematic diagram of lung metastatic tumor imaging. (b) Bioluminescence image of lung metastatic mice and bright field, and NIR-II image of excised lung metastatic tumors at 48 h after i.v. injection with free ICG and CMPI (ICG = 0.2 mM, 0.1 mL). The white-dashed circles outline the lung. The red-dashed circles present tumors. Laser: 808 nm, 900 nm long-pass filter, 75 mW cm−2, exposure time: 20 ms. (c) NIR-II images and HE staining of the region of interest (ROI) from the ‘right’ lung metastatic tumor in panel (b, CMPI). (d) HE staining of the ‘left’ lung metastatic tumor section. Representative tumors were labeled with black-dashed circles. (e) Tumor-to-normal ratio of NIR-II imaging of lung metastatic tumors according to panel (b). ‘Left’ and ‘right’ respectively present the location on the left and right side of the lung in panel (b, CMPI). Scattered white patches on the left side of the lung are tumors in the NIR-II images. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)#