Nanoparticles with antioxidant enzymes protect injured spinal cord from neuronal cell apoptosis by attenuating mitochondrial dysfunction

JOURNAL OF CONTROLLED RELEASE

卷:317

Article

Andrabi, Syed Suhail¹  Yang, Jun^1,2  Gao, Yue¹  Kuang, Youzhi¹  Labhasetwar, Vinod¹ 

[1] Cleveland Clin, Lerner Res Inst, Dept Biomed Engn, Cleveland, OH 44195 USA

[2] Xiamen Univ, Sch Med, Xiangan Hosp, Dept Neurosurg, Xiamen, Peoples R China

关键词: Nanoparticles;    Antioxidant enzymes;    Reactive oxygen species;    Neurodegeneration;    Biodegradable polymer;    Sustained release;   

DOI  :  10.1016/j.jconrel.2019.12.001

来源: Elsevier

【 摘 要 】

In spinal cord injury (SCI), the initial damage leads to a rapidly escalating cascade of degenerative events, known as secondary injury. Loss of mitochondrial homeostasis after SCI, mediated primarily by oxidative stress, is considered to play a crucial role in the proliferation of secondary injury cascade. We hypothesized that effective exogenous delivery of antioxidant enzymes - superoxide dismutase (SOD) and catalase (CAT), encapsulated in biodegradable nanoparticles (nano-SOD/CAT) - at the lesion site would protect mitochondria from oxidative stress, and hence the spinal cord from secondary injury. Previously, in a rat contusion model of severe SCI, we demonstrated extravasation and retention of intravenously administered nanoparticles specifically at the lesion site. To test our hypothesis, a single dose of nano-SOD/CAT in saline was administered intravenously 6 h post-injury, and the spinal cords were analyzed one week post-treatment. Mitochondria isolated from the affected region of the spinal cord of nano-SOD/CAT-treated animals demonstrated significantly reduced mitochondrial reactive oxygen species (ROS) activities, increased mitochondrial membrane potential, reduced calcium levels, and also higher adenosine triphosphate (ATP) production capacity than those isolated from the spinal cords of untreated control or SOD/CAT solution treated animals. Although the treatment did not achieve the same mitochondrial function as in the spinal cords of sham control animals, it significantly attenuated mitochondrial dysfunction following SCI. Further, immunohistochemical analyses of the spinal cords of treated animals showed significantly lower ROS, cleaved caspase-3, and cytochrome c activities, leading to reduced spinal cord neuronal cell apoptosis and smaller lesion area than in untreated animals. These results imply that the treatment significantly attenuated progression of secondary injury that was also reflected from less weight loss and improved locomotive recovery of treated vs. untreated animals. In conclusion, nano-SOD/CAT mitigated activation of cascade of degenerating factors by protecting mitochondria and hence the spinal cord from secondary injury. An effective treatment during the acute phase following SCI could potentially have a positive long-term impact on neurological and functional recovery.

【 授权许可】

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