【JACS】港中深唐本忠院士、武汉大学王富安等|52.7%高光热转换效率！新型近红外铂(II)配合物实现肿瘤诊疗新突破#

文章标题： A Multifunctional Near-Infrared Platinum(II) Agent for High-Performance Chemo-Photothermal Therapy

通讯作者： Jacky W. Y. Lam, Wenqian Yu, Fuan Wang, Ben Zhong Tang

文章链接： https://doi.org/10.1021/jacs.6c03316

文章概要#

引言#

传统顺铂等铂类化疗药物在临床应用中由于缺乏诊断导向、极易产生耐药性以及单一化疗疗效有限而面临巨大挑战。光疗作为一种新兴的诊疗手段受到广泛关注，但传统的近红外荧光探针常常受限于聚集诱导发光淬灭效应，且在深层组织中的成像清晰度不足。为了打破这一瓶颈，研究团队创新性地设计出一种兼具近红外发射、聚集诱导发光（AIE）特征与高效光热效应的多功能双齿铂(II)配合物。该研究不仅规避了传统环金属铂配合物对吡啶类配体的依赖，还通过前沿生物信息学方法精准定位了细胞耐热的关键靶点，为构建新一代高性能、个性化的肿瘤诊疗一体化平台提供了全新思路。

Scheme 1. (A) Properties of Previously Reported Platinum Complexes and the Newly Prepared BSeTPE-Pt-ac. (B) A Multifunctional Platinum(II) Agent for Imaging-Guided Gene-Regulation Synergized Chemo-PTT#

主要实验及结论#

研究人员利用高效的苏木基偶联等反应成功合成了目标配合物BSeTPE-Pt-ac。单晶X射线衍射与理论计算表明，该配合物通过六元环模式与苯并硒二唑核心配位，显著拓宽了电子共轭效应，并借助强烈的分子内金属向配体电荷转移实现了红移的近红外发射；同时，外围高度扭曲的四苯乙烯单元有效增大了分子空间位阻，限制了分子内的非辐射衰减，从而赋予其独特的聚集增强发光特性。光热测试显示该配合物表现出高度敏感且依赖于浓度和功率的光热转换行为，其纳米颗粒的光热转换效率高达52.7%。在细胞与动物实验中，利用叶酸修饰的聚乳酸-羟基乙酸共聚物将其与针对抗凋亡基因BCL2的基因沉默反义寡核苷酸进行共包裹，成功制备出具备主动靶向能力的纳米诊疗系统，在近红外荧光成像和光热成像的双重引导下精准定位了肿瘤边界。

Figure 1. X-ray crystal analysis of BSeTPE and BSeTPE-Pt-ac. Crystal structures of (A) BSeTPE and (B) BSeTPE-Pt-ac. (C) Molecular packings with intermolecular interactions of BSeTPE and BSeTPE-Pt-ac (hydrogen atoms and solvents were omitted for the sake of clarity).#

Figure 2. Frontier molecular orbitals of (A) BSeTPE and (B) BSeTPE-Pt-ac based on the optimized ground-state geometries. Simulated UV–vis absorption spectra of (C) BSeTPE and (D) BSeTPE-Pt-ac in THF solutions. The hole–electron distribution and the interfragment charge transfer of (E) BSeTPE and (F) BSeTPE-Pt-ac upon the vertical excitation in THF solutions. The intrinsic CT and LE percentages were calculated to characterize the excitation properties. Plots of reorganization energy vs normal mode wavenumber of BSeTPE in (G) THF solutions and (H) crystalline phase. Plots of reorganization energy vs normal mode wavenumber of BSeTPE-Pt-ac in (I) THF solutions and (J) crystalline phase. Inset: the proportions of bond length, bond angle, and dihedral angle contributed to the total reorganization energy.#

Figure 3. Normalized (A) absorption and (B) PL spectra of BSeTPE and BSeTPE-Pt-ac in THF solutions (10–5 M), and BSeTPE-Pt-ac in nanoparticles (named Pt NPs). PL spectra of (C) BSeTPE and (D) BSeTPE-Pt-ac in toluene/cyclohexane mixtures with different cyclohexane fractions (_f_c). (E) Temperature curves of BSeTPE-Pt-ac (50 μM, 0.6 W cm–2, 5 min, 660 nm) and PBS. (F) Photothermal behavior of BSeTPE-Pt-ac at different concentrations (0.3 W cm–2, 5 min, 660 nm) and (G) power densities (50 μM, 5 min, 660 nm). (H) Photothermal stability of BSeTPE-Pt-ac (50 μM, 0.6 W cm–2, 5 min, 660 nm). (I) Photothermal heating/cooling curves of BSeTPE-Pt-ac. (J) Photothermal conversion efficiency of BSeTPE-Pt-ac. (K) Photothermal effect of F–Pt NPs with varied concentrations (0.5 W cm–2, 5 min, 660 nm). (L) PTI of irradiated PBS and F–Pt NPs (200 μg mL–1) at different times.#

Figure 4. (A) GSEA analysis of pivotal unfolded protein binding in PTT vs PBS groups. (B) Circle heatmap showing differentially expressed HSPs in PTT vs PBS groups. (C) Analysis of the gene interaction networks based on the GeneMANIA database. Networks, 1, physical interactions, 2, coexpression, 3, predicted, 4, colocalization, 5, genetic interactions, 6, pathway, and 7, shared protein domains. (D) Images and (E) analysis of tumor cells MCF-7 and normal cells MCF-10A treated with tumor-targeting F–Pt NPs or nontargeting Pt NPs. (F) Cell viability to F–Pt NPs. (G) Cell viability, (H) cell apoptosis, and (I) DNA damage assays toward MCF-7 cells. (J) Cell viability toward 4T1 cells. (K) Analysis of mRNA levels: Group 1 (G1), PBS; G2, cisplatin; G3, F–Pt NPs + laser; G4, ASO/F–Pt NPs; and G5, ASO/F–Pt NPs + laser. Cells were treated with PBS, cisplatin (12 μg mL–1), Pt NPs (200 μg mL–1), F–Pt NPs (200 μg mL–1), ASO/Pt NPs (200 μg mL–1), and ASO/F–Pt NPs (200 μg mL–1), for 36 h with or without laser irradiation (0.5 W cm–2, 5 min, 660 nm). **p < 0.0001, *p < 0.001, and ns, not significant (one-way analysis of variance [ANOVA] followed by Tukey’s multiple comparisons test). Data were presented as mean ± s.d. (n = 3).#

生物信息学转录组与蛋白质组学测序结果进一步揭示，光热治疗引起的超热应激会触发肿瘤细胞上调热休克蛋白并激活动中特异性的抗凋亡补偿机制。通过引入基因治疗手段，该纳米系统在低纳米摩尔浓度下便能显著抑制肿瘤组织中BCL2蛋白的表达，极大地降低了细胞对化疗和热疗的凋亡阈值，使肿瘤细胞对铂剂诱导的DNA损伤更加敏感。在小鼠乳腺癌模型中，该协同治疗方案展现出极其优异的肿瘤生长抑制效果，肿瘤重量抑制率高达98.5%，并成功将肺部转移结节几乎完全根除。深度免疫微环境分析显示，此方案不仅能诱导广泛的细胞坏死与血管阻断，还能显著上调免疫相关信号通路、促进免疫细胞浸润，从而重塑肿瘤微环境。

Figure 5. (A, E) FLI and (B, F) analysis on subcutaneous and orthotopic breast cancer-bearing mice, respectively. (C) Analysis and (D) images of ex vivo tissues (Tu: tumor, He: heart, Lu: lung, Li: liver, Sp: spleen, and _K_i: kidney) of the subcutaneous mice model. (G) Analysis of ex vivo tissues of the orthotopic mice model. (H) Imaging and (I, J) analysis of orthotopic tumor-bearing mice at different excitation/emission wavelengths. (K) PTI and (L) temperature changes of PBS or F–Pt NP-treated mice (0.5 W cm–2, 5 min, 660 nm). Data were presented as mean ± s.d. (n = 4).#

Figure 6. In vivo antitumor effect of F–Pt NPs on subcutaneous breast cancer. (A) Protocol illustration, (B) photographs of tumors, (C) tumor weights, and (D) tumor–growth curves. (E) H&E staining and (F) TUNEL staining images. **p < 0.0001, *p < 0.001, **p < 0.01, and ns, not significant (one-way analysis of variance [ANOVA] followed by Tukey’s multiple comparisons test). Data were presented as mean ± s.d. (n = 5).#

总结及展望#

该研究成功报道了一种集近红外成像、AIE效应与光热治疗于一体的多功能铂(II)诊疗剂。通过合理的分子结构设计与生物信息学辅助的治疗方案优化，该系统不仅彻底攻克了传统铂类药物功能单一和聚集发光淬灭的缺陷，还通过基因调节手段有效克服了肿瘤的光热耐受性，实现了高效的抗肿瘤增殖与抗转移协同治疗。这一集化疗、光热治疗与基因调控于一体的创新策略，展现出极高的临床转化潜力与优异的生物安全性，为未来开发先进的智能化多功能抗肿瘤药物开辟了全新的里程碑。