癌症是一个全球性的健康问题。目前常用的治疗方式包括手术、化疗、放疗和免疫治疗。然而由于肿瘤内异质性的客观存在，单一治疗模式往往呈现一定的疗效局限性。近年研究发现，化疗与免疫治疗在特定病理条件下联用可产生协同效应。小分子BH3模拟物ABT已被证实能够高效诱导肿瘤细胞凋亡；而TLR7/8双激动剂R848可有效逆转免疫抑制性肿瘤微环境并增强抗原特异性免疫应答。开发精准可控的共递送系统，同步调控肿瘤微环境中的细胞凋亡与免疫激活通路，有望提升治疗效果。然而，药物理化性质不同、给药靶点差异仍是共给药的障碍，因此，设计合适的共递送载体是亟需解决的问题。

首先选择D-α-生育酚聚乙二醇1000琥珀酸酯（TPGS）为载体，共装载化疗药物ABT及免疫佐剂R848，构建共递送纳米粒TPGS/ABT+R848 NPs。体外药效实验表明，TPGS/ABT+R848 NPs对4T1细胞的IC₅₀值为0.30 μg/mL，比游离ABT低34倍。在4T1荷瘤小鼠模型中，TPGS/ABT+R848 NPs肿瘤抑制率为75.3%，是阳性组的1.90倍，呈现出较好的肿瘤抑制效果。相较于单独给药的纳米粒，联合给药药效更佳。结果表明，ABT与R848联用构建共递送体系可有效提升药物疗效。

在化疗免疫共递送体系的基础上，以带有RGD的聚谷氨酸（RGD-PGA）为载体，共载线粒体靶头TPP、ABT和R848，构建双重靶向共递送体系R/ART NPs。体外细胞实验证实纳米粒具有很好的肿瘤细胞抑制效果，其IC₅₀值为0.16 μg/mL，与游离ABT相比抗肿瘤效率提高86.9倍。在荷瘤小鼠模型中，R/ART NPs给药14天后肿瘤消失率为33.3%，肿瘤抑制率为95.4%，并显著延长小鼠中位生存期，治愈率为28.6%。HE染色表明该制剂无显著毒性，进一步研究证实R/ART NPs可通过增加肿瘤组织内T细胞浸润、促进TAMs极化以及增强DCs成熟以重塑免疫微环境。

为进一步提升抗肿瘤效果，对双靶向共递送体系的结构进行优化，利用γ-PGA和ε-聚赖氨酸（ε-PLL）的静电相互作用设计主动靶向核壳纳米体系RRTA NPs。RRTA NPs在体内外药效学实验中均展现了出色的治疗效果，IC₅₀值为0.03 μg/mL，肿瘤体积抑瘤率高达96.9%，并显著延长小鼠的中位生存期，治愈率为16.7%。机制研究表明，RRTA NPs有效增强T细胞的浸润，成功地使TME内的M2型巨噬细胞再极化，并刺激树突状细胞的成熟。对比不同装载方式的体内药效结果，RRTA NPs在肿瘤抑制率指标上表现出微弱优势（TIR=96.8% vs 95.9%），进一步体内免疫分析显示核壳结构纳米粒展现出更优的免疫调控性能。与R/ART NPs相比，RRTA NPs具有更强的T细胞活化、巨噬细胞重极化及促进树突状细胞成熟的能力。

最后，基于“药辅合一”理念，引入具有线粒体调控及免疫调节功能的岩藻多糖（FU）为载体，利用自组装及静电相互作用构建了核壳共递送体系FUR/ART NPs。MTT结果表明，FUR/AT NPs的IC₅₀值为0.10 μg/mL。研究发现，FU载药体系可通过增强线粒体膜通透性，显著提升促凋亡效应。此外，FU具有促进树突状细胞成熟及巨噬细胞重极化的能力，FUR/AT NPs组较游离FU溶液组呈现出明显免疫增强。体内药效学实验表明，FU具有中等抗肿瘤效果，FUR/AT NPs组的抑制率为和94.6%，并且出现3例肿瘤完全消退的情况。脏器指数评估表明纳米制剂具有良好生物安全性，为临床转化奠定基础。免疫分析显示，治疗组肿瘤引流淋巴结内CD4+/CD8+ T细胞浸润水平及成熟树突状细胞比例显著提升，证实其可协同增强特异性免疫应答。

综上所述，本研究通过对递送系统的多级优化，成功实现化疗药物ABT与免疫调节剂R848的精准共递送，建立了基于时空协同的化疗-免疫联合治疗新策略，为抗肿瘤联合治疗提供了思路。

Cancer is a global health problem. Commonly used treatment modalities include surgery, chemotherapy, radiotherapy, and immunotherapy. However, due to the objective existence of intra-tumor heterogeneity, single-treatment modalities often present significant efficacy limitations. Recent studies have found that combining chemotherapy and immunotherapy can produce synergistic effects under specific pathological conditions. The small molecule BH3 mimetic ABT is highly effective in inducing apoptosis in tumor cells, while the TLR7/8 dual agonist R848 effectively reverses the immunosuppressive tumor microenvironment and enhances antigen-specific immune response. The development of a precise and controllable co-delivery system to synchronize apoptosis and immune activation pathways in the tumor microenvironment is expected to significantly enhance therapeutic efficacy. However, differences in the physicochemical properties of drugs and delivery targets are still barriers to co-delivery, and therefore, the design of suitable co-delivery carriers is an urgent problem to be solved.

Firstly, D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) was selected as the carrier and co-loaded with chemotherapeutic drug ABT and immunoadjuvant R848 to construct the co-delivery nanoparticles TPGS/ABT+R848 NPs. In vitro pharmacodynamic experiments showed that the IC₅₀ value of TPGS/ABT+R848 NPs was 0.30 μg/mL for 4T1 cells, which was 34 times lower than that of free ABT by 34-fold. In the 4T1 tumor-bearing mouse model, the tumor inhibition rate of TPGS/ABT+R848 NPs was 75.3%, which was 1.90 times higher than that of the positive group, presenting a better tumor inhibition effect. Compared with single-loaded nanoparticles, the combined administration was more effective. The results suggest that combining ABT and R848 to construct a co-delivery system can enhance drug efficacy.

Based on the chemo-immunotherapy co-delivery, the dual-targeting co-delivery system R/ART NPs was constructed using polyglutamic acid modified with RGD (RGD-PGA) as a carrier to co-carry the mitochondrial targets TPP, ABT and R848. In vitro cellular experiments demonstrated that nanoparticles had a perfect tumor cell inhibitory effect, with an IC₅₀ of 0.16 μg/mL, and 86.9-fold increase in anti-tumor efficiency compared with free ABT. In the tumor-bearing mouse model, R/ART NPs administration for 14 days resulted in 33.3% tumor disappearance, 95.4% tumor suppression, and significantly prolonged the median survival of mice with a cure rate of 28.6%. HE staining demonstrated no significant toxicity of this agent, and further studies confirmed that R/ART NPs could remodel the immune microenvironment by significantly increasing T-cell infiltration in tumor tissues, promoting polarization of TAMs, and enhancing the maturation of DCs.

To further enhance the anti-tumor effect, the structure of the dual-targeted co-delivery system was optimized. The electrostatic interaction of γ-PGA and ε-polylysine (ε-PLL) was utilized to design actively targeted core-shell nanosystems RRTA NPs. RRTA NPs exhibited excellent therapeutic efficacy in both in vivo and ex vivo pharmacodynamic experiments, with an IC₅₀ value of 0.03 μg/mL, a high tumor-volume inhibitory rate of 96.9%, and a significant prolongation of the mice's median survival with a cure rate of 16.7%. Mechanistic studies showed that RRTA NPs effectively enhanced T-cell infiltration, successfully repolarized M2-type macrophages within the TME, and stimulated the maturation of dendritic cells. When comparing the in vivo therapeutic efficacy of different drug-loading approaches, RRTA NPs demonstrated a slight advantage in tumor inhibition rate (TIR = 96.8% vs. 95.9%). Further in vivo immunological analysis revealed that the core-shell structured nanoparticles exhibited superior immune-modulatory performance. Compared to R/ART NPs, RRTA NPs showed enhanced capabilities in T cell activation, macrophage repolarization, and promoting dendritic cell maturation.

Finally, based on the concept of 'drug-excipient integration,' a core-shell co-delivery system (FUR/ART NPs) was constructed using fucoidan (FU)—a polysaccharide with mitochondrial regulatory and immunomodulatory functions—as the carrier, through self-assembly and electrostatic interactions. MTT assay results indicated that FUR/ART NPs exhibited an IC₅₀ value of 0.10 μg/mL. The study revealed that the FU-based drug-loading system significantly enhanced pro-apoptotic effects by increasing mitochondrial membrane permeability. Furthermore, FU demonstrated the ability to promote dendritic cell maturation and macrophage repolarization, with the FUR/ART NPs group showing markedly stronger immune enhancement than the free FU solution. In vivo pharmacodynamic experiments demonstrated that FU exhibited moderate antitumor efficacy, achieving a tumor inhibition rate of 94.6% in the FUR/ART NPs group, including three cases of complete tumor regression. Organ index evaluation confirmed the excellent biosafety of the nanoformulation, laying the foundation for clinical translation. Immunological analysis revealed a significant increase in CD4+/CD8+ T cell infiltration levels and the proportion of mature dendritic cells in tumor-draining lymph nodes within the treatment group, confirming its ability to synergistically enhance specific immune responses.

In summary, the precise co-delivery of chemotherapeutic drug ABT and immunomodulator R848 was successfully achieved through the multilevel optimization of the delivery system, establishing a new strategy of chemo-immunotherapy combination therapy based on spatiotemporal synergy, and providing ideas for anti-tumor combination therapy.