School of Biosciences and Bioengineering, Indian Institute of Technology Mandi, Kamand, Mandi, Himachal Pradesh 175075, India.
School of Biological Sciences, National Institute of Science Education and Research, Homi Bhabha National Institute, Jatni, Odisha 752050, India.
ACS Appl Mater Interfaces. 2023 Aug 23;15(33):39081-39098. doi: 10.1021/acsami.3c06186. Epub 2023 Aug 11.
Recent developments in nanomaterials with programmable optical responses and their capacity to modulate the photothermal effect induced by an extrinsic source of light have elevated plasmonic photothermal therapy (PPTT) to the status of a favored treatment for a variety of malignancies. However, the low penetration depth of near-infrared-I (NIR-I) lights and the need to expose the human body to a high laser power density in PPTT have restricted its clinical translation for cancer therapy. Most nanostructures reported to date exhibit limited performance due to (i) activity only in the NIR-I region, (ii) the use of intense laser, (iii) need of large concentration of nanomaterials, or (iv) prolonged exposure times to achieve the optimal hyperthermia state for cancer phototherapy. To overcome these shortcomings in plasmonic nanomaterials, we report a bimetallic palladium nanocapsule (Pd Ncap)─with a solid gold bead as its core and a thin, perforated palladium shell─with extinction both in the NIR-I as well as the NIR-II region for PPTT applications toward cancer therapy. The Pd Ncap demonstrated exceptional photothermal stability with a photothermal conversion efficiency of ∼49% at the NIR-II (1064 nm) wavelength region at a very low laser power density of 0.5 W/cm. The nanocapsules were further surface-functionalized with Herceptin (Pd Ncap-Her) to target the breast cancer cell line SK-BR-3 and exploited for PPTT applications using NIR-II light. Pd Ncap-Her caused more than 98% cell death at a concentration of just 50 μg/mL and a laser power density of 0.5 W/cm with an output power of only 100 mW. Flow cytometric and microscopic analyses revealed that Pd Ncap-Her-induced apoptosis in the treated cancer cells during PPTT. Additionally, Pd Ncaps were found to have reactive oxygen species (ROS) scavenging ability, which can potentially reduce the damage to cells or tissues from ROS produced during PPTT. Also, Pd Ncap demonstrated excellent biocompatibility and was highly efficient in photothermally ablating tumors in mice. With a high photothermal conversion and killing efficiency at very low nanoparticle concentrations and laser power densities, the current nanostructure can operate as an effective phototherapeutic agent for the treatment of different cancers with ROS-protecting ability.
最近，具有可编程光学响应的纳米材料的发展及其调节外源性光源诱导的光热效应的能力，将等离子体光热疗法（PPTT）提升到了治疗各种恶性肿瘤的首选治疗方法的地位。然而，近红外-I（NIR-I）光的低穿透深度以及在 PPTT 中需要将人体暴露在高激光功率密度下，限制了其在癌症治疗中的临床转化。迄今为止，大多数报道的纳米结构由于以下原因而表现出有限的性能：（i）仅在 NIR-I 区域活跃，（ii）使用强激光，（iii）需要纳米材料的高浓度，或（iv）长时间暴露于实现癌症光疗的最佳热疗状态。为了克服等离子体纳米材料的这些缺点，我们报告了一种双金属钯纳米胶囊（Pd Ncap）-具有实心金珠作为其核心和薄的、穿孔的钯壳-在 NIR-I 以及 NIR-II 区域都具有消光作用，可用于癌症治疗的 PPTT 应用。Pd Ncap 在非常低的激光功率密度 0.5 W/cm 下，在 NIR-II（1064nm）波长区域表现出出色的光热稳定性，光热转换效率约为 49%。纳米胶囊进一步用赫赛汀（Pd Ncap-Her）表面功能化，以靶向乳腺癌细胞系 SK-BR-3，并利用 NIR-II 光进行 PPTT 应用。在浓度仅为 50μg/mL 和激光功率密度为 0.5 W/cm 的情况下，Pd Ncap-Her 导致超过 98%的细胞死亡，输出功率仅为 100mW。流式细胞术和显微镜分析显示，Pd Ncap-Her 在 PPTT 过程中诱导了治疗癌细胞的细胞凋亡。此外，Pd Ncaps 具有清除活性氧物质（ROS）的能力，这可能会减少 PPTT 过程中产生的 ROS 对细胞或组织的损伤。此外，Pd Ncap 表现出出色的生物相容性，并且在小鼠中光热消融肿瘤的效率非常高。由于具有高的光热转换和杀伤效率，在非常低的纳米颗粒浓度和激光功率密度下，当前的纳米结构可以作为一种有效的光热治疗剂，用于治疗具有 ROS 保护能力的不同癌症。
