多功能近红外染料 IR-817 包封在白蛋白纳米颗粒中，用于增强黑色素瘤的成像和光热治疗。

BACKGROUND: Near-infrared cyanine dyes have high sensitivity and spatial resolution imaging capabilities, but they also have unavoidable drawbacks such as photobleaching, low water solubility, fluorescence quenching, and toxic side effects. As an effective biologic drug carrier, albumin combines with cyanine dyes to form albumin@dye nanoparticles. These nanoparticles can alleviate the aforementioned issues and are widely used in tumor imaging and photothermal therapy. METHODS: Herein, a newly synthesized near-infrared dye IR-817 was combined with bovine serum albumin (BSA) to create BSA@IR-817 nanoparticles. Through the detection of fluorescence emission and absorption, the optimal concentration and ratio of BSA and IR-817 were determined. Subsequently, dynamic light scattering (DLS) measurements and scanning electron microscopy (SEM) were used for the physical characterization of the BSA@IR-817 nanoparticles. Finally, in vitro and in vivo experiments were conducted to assess the fluorescence imaging and photothermal therapeutic potential of BSA@IR-817 nanoparticles. RESULTS: IR-817 was adsorbed onto the BSA carrier by covalent conjugation and supramolecular encapsulation, resulting in the formation of dispersed, homogeneous, and stable nanoparticles with a particle size range of 120-220 nm. BSA@IR-817 not only improved the poor water solubility, fluorescence quenching, and toxic side effects of IR-817 but also enhanced the absorption and fluorescence emission peaks in the near-infrared region, as well as the fluorescence in the visible spectrum. In addition, BSA@IR-817 combined with laser 808 irradiation was able to convert light energy into heat energy with temperatures exceeding 50 °C. By creating a mouse model of subcutaneous melanoma, it was discovered that the tumor inhibition rate of BSA@IR-817 was greater than 99% after laser irradiation and that it achieved nearly complete tumor ablation without causing significant toxicity. CONCLUSION: Our research, therefore, proposes the use of safe and effective photothermal nanoparticles for the imaging, diagnosis, and treatment of melanoma, and offers a promising strategy for future biomedical applications.

背景：近红外菁染料具有高灵敏度和空间分辨率成像能力，但也存在不可避免的缺点，如光漂白、低水溶性、荧光猝灭和毒性副作用。作为一种有效的生物药物载体，白蛋白与菁染料结合形成白蛋白@染料纳米颗粒。这些纳米颗粒可以缓解上述问题，广泛应用于肿瘤成像和光热治疗。

方法：在此，我们将新合成的近红外染料 IR-817 与牛血清白蛋白（BSA）结合，制备 BSA@IR-817 纳米颗粒。通过荧光发射和吸收检测，确定了 BSA 和 IR-817 的最佳浓度和比例。随后，采用动态光散射（DLS）测量和扫描电子显微镜（SEM）对 BSA@IR-817 纳米颗粒进行物理表征。最后，进行了体外和体内实验，评估了 BSA@IR-817 纳米颗粒的荧光成像和光热治疗潜力。

结果：IR-817 通过共价键合和超分子包封吸附在 BSA 载体上，形成分散、均匀、稳定的纳米颗粒，粒径范围为 120-220nm。BSA@IR-817 不仅提高了 IR-817 的不良水溶性、荧光猝灭和毒性副作用，而且增强了近红外区域的吸收和荧光发射峰以及可见光谱中的荧光。此外，BSA@IR-817 与激光 808 照射结合，能够将光能转化为超过 50°C 的热能。通过建立皮下黑色素瘤小鼠模型，发现激光照射后 BSA@IR-817 的肿瘤抑制率大于 99%，且几乎完全消融肿瘤，无明显毒性。

结论：因此，我们的研究提出了使用安全有效的光热纳米颗粒进行黑色素瘤的成像、诊断和治疗，为未来的生物医学应用提供了有前途的策略。