Department of Tuberculosis, The Second Hospital of Nanjing, Nanjing University of Chinese Medicine, Nanjing, People's Republic of China.
Medical School of Southeast University, Nanjing, People's Republic of China.
Int J Nanomedicine. 2023 Jan 27;18:489-503. doi: 10.2147/IJN.S395246. eCollection 2023.
Central nervous system tuberculosis (CNS-TB) is the most devastating form of extrapulmonary tuberculosis. Rifampin (RIF) is a first-line antimicrobial agent with potent bactericidal action. Nonetheless, the blood-brain barrier (BBB) limits the therapeutic effects on CNS-TB. Exosomes, however, can facilitate drug movements across the BBB. In addition, exosomes show high biocompatibility and drug-loading capacity. They can also be modified to increase drug delivery efficacy. In this study, we loaded RIF into exosomes and modified the exosomes with a brain-targeting peptide to improve BBB permeability of RIF; we named these exosomes ANG-Exo-RIF.
Exosomes were isolated from the culture medium of BMSCs by differential ultracentrifugation and loaded RIF by electroporation and modified ANG by chemical reaction. To characterize ANG-Exo-RIF, Western blot (WB), nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM) were performed. Bend.3 cells were incubated with DiI labeled ANG-Exo-RIF and then fluorescent microscopy and flow cytometry were used to evaluate the targeting ability of ANG-Exo-RIF in vitro. Fluorescence imaging and frozen section were used to evaluate the targeting ability of ANG-Exo-RIF in vivo. MIC and MBC were determined through microplate alamar blue assay (MABA).
A novel exosome-based nanoparticle was developed. Compared with untargeted exosomes, the targeted exosomes exhibited high targeting capacity and permeability in vitro and in vivo. The MIC and MBC of ANG-Exo-RIF were 0.25 μg/mL, which were sufficient to meet the clinical needs.
In summary, excellent targeting ability, high antitubercular activity and biocompatibility endow ANG-Exo-RIF with potential for use in future translation-aimed research and provide hope for an effective CNS-TB treatment.
中枢神经系统结核（CNS-TB）是最具破坏性的肺外结核形式。利福平（RIF）是一种具有强大杀菌作用的一线抗菌药物。然而，血脑屏障（BBB）限制了其对 CNS-TB 的治疗效果。外泌体可以促进药物穿过 BBB。此外，外泌体具有高生物相容性和载药能力。它们还可以被修饰以提高药物输送效率。在这项研究中，我们将 RIF 加载到外泌体中，并通过化学反应用脑靶向肽修饰外泌体，以提高 RIF 对 BBB 的通透性；我们将这些外泌体命名为 ANG-Exo-RIF。
通过差速超速离心从 BMSCs 培养基中分离出外泌体，通过电穿孔加载 RIF，并通过化学反应修饰 ANG。为了表征 ANG-Exo-RIF，进行了 Western blot（WB）、纳米颗粒跟踪分析（NTA）和透射电子显微镜（TEM）。将 Bend.3 细胞与 DiI 标记的 ANG-Exo-RIF 孵育，然后使用荧光显微镜和流式细胞术评估 ANG-Exo-RIF 的体外靶向能力。荧光成像和冷冻切片用于评估 ANG-Exo-RIF 的体内靶向能力。通过微孔板阿尔玛蓝测定（MABA）确定 MIC 和 MBC。
开发了一种新型的基于外泌体的纳米颗粒。与非靶向外泌体相比，靶向外泌体在体外和体内具有高靶向能力和通透性。ANG-Exo-RIF 的 MIC 和 MBC 分别为 0.25 μg/mL，足以满足临床需求。
综上所述，优异的靶向能力、高抗结核活性和生物相容性使 ANG-Exo-RIF 具有未来转化研究的潜力，并为有效的 CNS-TB 治疗带来希望。
