Department of General Surgery, First Affiliated Hospital of Xi'an Jiaotong University, Xian, China.
Department of Medical Oncology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
Front Immunol. 2023 Jul 17;14:1228581. doi: 10.3389/fimmu.2023.1228581. eCollection 2023.
PD-1/PD-L1 immune checkpoint inhibitors are currently the most commonly utilized agents in clinical practice, which elicit an immunostimulatory response to combat malignancies. However, all these inhibitors are currently administered injection using antibody-based therapies, while there is a growing need for oral alternatives.
This study has developed and synthesized exosome-wrapped gold-peptide nanocomplexes with low immunogenicity, which can target PD-L1 and activate antitumor immunity through oral absorption. The PDL1 was characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and gel silver staining. The transmembrane ability of PDL1 was evaluated by flow cytometry and immunofluorescence. Cell viability was determined using the Cell Counting Kit-8 (CCK-8) assay. ELISA experiments were conducted to detect serum and tissue inflammatory factors, as well as serum biochemical indicators. Tissue sections were stained with H&E for the evaluation of the safety of PDL1. An MC38 colon cancer model was established in immunocompetent C56BL/6 mice to evaluate the effects of PDL1 on tumor growth . Immunohistochemistry (IHC) staining was performed to detect cytotoxicity factors such as perforin and granzymes.
First, PDL1 was successfully synthesized, and milk exosome membranes were encapsulated through ultrasound, repeated freeze-thaw cycles, and extrusion, resulting in the synthesis of PDL1. Multiple characterization results confirmed the successful synthesis of PDL1 nanoparticles. Furthermore, our data demonstrated that PDL1 exhibited excellent colloidal stability and superior cell transmembrane ability. and experiments revealed that PDL1 did not cause damage to multiple systemic organs, demonstrating its good biocompatibility. Finally, in the MC38 colon cancer mouse model, it was discovered that PDL1 could inhibit the progression of colon cancer, and this tumor-suppressive effect was mediated through the activation of tumor-specific cytotoxic T lymphocyte (CTL)-related immune responses.
This study has successfully designed and synthesized an oral nanotherapeutic, PDL1, which demonstrates small particle size, excellent colloidal stability, transmembrane ability in tumor cells, and biocompatibility. experiments have shown that it effectively activates T-cell immunity and exerts antitumor effects.
PD-1/PD-L1 免疫检查点抑制剂是目前临床实践中最常用的药物，可引发免疫刺激反应以对抗恶性肿瘤。然而，所有这些抑制剂目前都通过抗体为基础的疗法进行注射，而人们对口服替代品的需求日益增长。
本研究开发并合成了具有低免疫原性的外泌体包裹的金-肽纳米复合物，可通过口服吸收靶向 PD-L1 并激活抗肿瘤免疫。通过透射电子显微镜（TEM）、动态光散射（DLS）、傅里叶变换红外光谱（FTIR）、X 射线光电子能谱（XPS）和凝胶银染色对 PDL1 进行了表征。通过流式细胞术和免疫荧光评估 PDL1 的跨膜能力。通过细胞计数试剂盒-8（CCK-8）测定法测定细胞活力。通过 ELISA 实验检测血清和组织炎症因子以及血清生化指标。用 H&E 对 PDL1 的组织切片进行染色，以评估其安全性。在免疫功能正常的 C56BL/6 小鼠中建立 MC38 结肠癌细胞模型，以评估 PDL1 对肿瘤生长的影响。进行免疫组织化学（IHC）染色以检测细胞毒性因子，如穿孔素和颗粒酶。
首先，成功合成了 PDL1，并通过超声、反复冻融循环和挤压将乳外泌体膜包裹，从而合成了 PDL1。多项特征分析结果证实了 PDL1 纳米颗粒的成功合成。此外，我们的数据表明 PDL1 表现出优异的胶体稳定性和卓越的细胞跨膜能力。和实验表明，PDL1 不会对多个系统器官造成损害，表现出良好的生物相容性。最后，在 MC38 结肠癌细胞模型中发现，PDL1 能够抑制结肠癌的进展，这种肿瘤抑制作用是通过激活肿瘤特异性细胞毒性 T 淋巴细胞（CTL）相关免疫反应介导的。
本研究成功设计并合成了一种口服纳米治疗药物 PDL1，其具有较小的粒径、优异的胶体稳定性、肿瘤细胞中的跨膜能力和生物相容性。实验表明，它能有效激活 T 细胞免疫，发挥抗肿瘤作用。
