ROS响应性纳米载体实现瘤内快速释放索拉非尼增强光动力学疗法抗肿瘤免疫治疗效果

Figure 1. The rapidly released sorafenib act with PDT significantly enhanced the antitumor immune response. (a, b) The 4T1 tumor growth was measured in BALB/c (a) and BALB/c-nu mice (b) from the day after tumor inoculation. PBS and NP-sfb/ce6 were given by intratumoral injection every day for 4 times (n = 6 per group). The doses of sorafenib and ce6 for each injection were 0.62 mg/kg and 0.65 mg/kg, respectively. The 660 nm laser irradiation (0.05 W/cm2, 120 min) was given at 2 h after nanoparticle administration. (c - e) Frequency of CD3⁺ T cells (c), the ratio of CD8⁺/CD4⁺ cells (d) and the frequency of MDSCs (CD11b⁺Gr-1⁺) in tumor-infiltrating CD45⁺cells in tumors were measured at the end of the tumor inhibition experiment. The tumor-bearing mice were treated as the same as in (a). (f) CLSM images showed the distribution of effector T cells (CD8⁺), helper T cells (CD4⁺), TAMs (F4/80⁺) and MDSCs (Gr1⁺) in tumor sections at the end of the tumor inhibition experiment. The tumor-bearing mice were treated as the same as in (a). Cell nuclei were stained with DAPI (blue), effector T cells were stained with anti-CD8 antibodies (green), helper T cells were stained with anti-CD4 antibodies (yellow), TAMs were stained with anti-F4/80 antibodies (red) and TAMs were stained with anti-Ly6G antibodies (purple). The scale bar is 40 μm. Data are presented as mean ± SEM (n = 6 per group). *, p < 0.05; **, p < 0.01; ***, p < 0.005; ****, p < 0.001; *****, p < 0.0005.
Figure 2. The rapidly released sorafenib act with PDT induced strong and long-lasting antitumor immune responses. The 4T1 tumor-bearing BALB/c mice were received PBS or NP-sfb/ce6 by intratumoral injection once. The doses of sorafenib and ce6 for each injection were 0.62 mg/kg and 0.65 mg/kg, respectively. The 660 nm laser irradiation (0.05 W/cm², 120 min) was given at 2 h after nanoparticle administration. Relative ratio of tumor-infiltrating CD8⁺ T cells (a), MDSCs (CD11b⁺Gr1⁺, b), and DCs (CD11b⁺CD11c⁺, c) in tumor-infiltrating CD45⁺ cells in tumors were measured by flow cytometry at 12 h, 36 h and 60 h after the treatment. Data are presented as mean ± SEM (n = 6 per group). *, p < 0.05.
光动力学疗法（photodynamic therapy, PDT）已经在临床中用于多种浅表实体瘤的治疗。光动力学疗法通过杀伤局部肿瘤细胞，引起肿瘤炎症反应，进一步诱导抗肿瘤免疫反应。然而，PDT的副作用，例如强烈的疼痛和皮肤光敏性，限制了PDT的广泛应用，也降低了其抗肿瘤功效。为了克服PDT的临床副作用，利用多激酶抑制剂-索拉非尼有效增强低剂量PDT对肿瘤细胞的细胞毒性，产生协同增效诱导肿瘤细胞凋亡的作用，有望进一步提高PDT的临床治疗效果。基于纳米颗粒的药物递送系统可实现肿瘤靶向药物递送、增强肿瘤治疗效果的同时减少药物的副作用。本文利用华南理工大学杨显珠教授课题组设计、合成的ROS响应性超支化高分子，制备高效携载光敏剂（二氢卟吩e6，ce6）和索拉非尼的纳米药物载体（NP-sfb/ce6），以达到增强PDT抗肿瘤反应的目的。在660nm激光照射下，ce6产生的ROS可迅速破坏纳米颗粒，导致索拉非尼的快速释放，与低剂量PDT产生协同作用，显著抑制肿瘤细胞增殖。利用小鼠原位乳腺癌模型，本文研究发现经过4次治疗之后，NP-sfb/ce6就能显著抑制乳腺癌肿瘤的生长，并导致肿瘤体积的减小，甚至肿瘤消除。进一步的机制研究发现，在660 nm激光照射下，NP-sfb/ce6能够诱导很强的T细胞依赖的抗肿瘤免疫反应。此外，本文提供的治疗策略还显著降低了肿瘤组织中髓系抑制性细胞（MDSC）的比例，减弱了肿瘤免疫抑制微环境，从而进一步增强了细胞毒性CD8⁺ T细胞的抗肿瘤作用。通过在治疗后的荷瘤小鼠体内接种第二个乳腺癌肿瘤，本文发现NP-sfb/ce6结合光照还可以产生非常强的全身性抗肿瘤免疫反应，从而有效地抑制了远端肿瘤的形成。综上，ROS响应性的纳米药物载体同时递送光敏剂和索拉菲尼的策略，实现PDT的同时调节肿瘤免疫微环境，可显著增强肿瘤免疫治疗效果，并减轻PDT毒副作用。
课题组简介

吉林大学第一医院孙天盟教授：博导，国家优青，现任吉林大学器官再造与移植教育部重点实验室（筹）副主任。近年来主要从事开发高效、靶向肿瘤细胞和免疫细胞递送基因、蛋白和多肽等药物的纳米药物递送系统，用于改造免疫系统功能，实现肿瘤免疫治疗及自身免疫病的治疗。至今在国际学术期刊发表SCI学术论文42篇，其中包括Science Translational Medicine， Science Advances, Angewandte Chemie International Edition， ACS Nano， Biomaterials等国际权威学术期刊，发表论文被引用3200余次。获得包括国家优秀青年科学基金、国家自然科学基金面上项目和国家重点研发计划纳米科技重点专项（青年项目）等项目支持。

基金资助

该研究得到了国家重点研发计划（2017YFA0208100, 2017YFA0205601）国家自然科学基金委（81571798, 91642208, 51822302, 81871478, 81422026）, 国家重大科学计划(973计划)（2015CB964400）和长江学者和创新团队发展计划（IRT_15R24）的支持。

论文信息

Paper information

Xu Sun^#, Zhiyang Cao^#, Kuirong Mao, Chenxi Wu, Hongmei Chen, Jialiang Wang, Xin Wang, Xiuxiu Cong, Yong Li, Xianying Meng^∗, Xianzhu Yang^∗, Yong-Guang Yang^∗, and Tianmeng Sun^∗. Photodynamic therapy produces enhanced efficacy of antitumor immunotherapy by simultaneously inducing intratumoral release of sorafenib. Biomaterials 2020,  119845.