Krishnan Mena Asha, Alimi Olawale A, Pan Tianshu, Kuss Mitchell, Korade Zeljka, Hu Guoku, Liu Bo, Duan Bin
Mary and Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, NE 68198, USA.
Division of Cardiovascular Medicine, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
Pharmaceutics. 2024 Jan 12;16(1):102. doi: 10.3390/pharmaceutics16010102.
The administration of therapeutics to peripheral nerve tissue is challenging due to the complexities of peripheral neuroanatomy and the limitations imposed by the blood-nerve barrier (BNB). Therefore, there is a pressing need to enhance delivery effectiveness and implement targeted delivery methods. Recently, erythrocyte-derived exosomes (Exos) have gained widespread attention as biocompatible vehicles for therapeutics in clinical applications. However, engineering targeted Exos for the peripheral nervous system (PNS) is still challenging. This study aims to develop a targeted Exo delivery system specifically designed for presynaptic terminals of peripheral nerve tissue. The clostridium neurotoxin, tetanus toxin-C fragment (TTC), was tethered to the surface of red blood cell (RBC)-derived Exos via a facile and efficient bio-orthogonal click chemistry method without a catalyst. Additionally, Cyanine5 (Cy5), a reactive fluorescent tag, was also conjugated to track Exo movement in both in vitro and in vivo models. Subsequently, Neuro-2a, a mouse neuronal cell line, was treated with dye-labeled Exos with/without TTC in vitro, and the results indicated that TTC-Exos exhibited more efficient accumulation along the soma and axonal circumference, compared to their unmodified counterparts. Further investigation, using a mouse model, revealed that within 72 h of intramuscular administration, engineered TTC-Exos were successfully transported into the neuromuscular junction and sciatic nerve tissues. These results indicated that TTC played a crucial role in the Exo delivery system, improving the affinity to peripheral nerves. These promising results underscore the potential of using targeted Exo carriers to deliver therapeutics for treating peripheral neuropathies.
由于周围神经解剖结构的复杂性以及血神经屏障（BNB）所带来的限制，向周围神经组织给药具有挑战性。因此，迫切需要提高递送效率并实施靶向递送方法。最近，红细胞衍生的外泌体（Exos）作为临床应用中治疗药物的生物相容性载体受到了广泛关注。然而，构建针对周围神经系统（PNS）的靶向Exos仍然具有挑战性。本研究旨在开发一种专门为周围神经组织突触前终末设计的靶向Exo递送系统。通过一种简便高效的无催化剂生物正交点击化学方法，将梭菌神经毒素破伤风毒素-C片段（TTC）连接到红细胞（RBC）衍生的Exos表面。此外，还连接了一种活性荧光标签花青素5（Cy5），以追踪Exos在体外和体内模型中的移动。随后，在体外将小鼠神经元细胞系Neuro-2a用有或没有TTC的染料标记Exos处理，结果表明，与未修饰的Exos相比，TTC-Exos在细胞体和轴突周围表现出更有效的积累。使用小鼠模型进行的进一步研究表明，在肌肉内给药72小时内，工程化的TTC-Exos成功转运到神经肌肉接头和坐骨神经组织中。这些结果表明，TTC在Exo递送系统中起着关键作用，提高了对周围神经的亲和力。这些有前景的结果强调了使用靶向Exo载体递送治疗药物治疗周围神经病变的潜力。
