Grup d'Enginyeria de Materials (Gemat), Institut Químic de Sarriá (IQS), Universitat Ramon Llull (URL), Via Augusta, Barcelona, Spain.
Sagetis Biotech, Via Augusta, Barcelona, Spain.
J Neuromuscul Dis. 2021;8(5):815-825. doi: 10.3233/JND-210662.
Duchenne Muscular Dystrophy (DMD) is one of the most common muscular dystrophies, caused by mutated forms of the dystrophin gene. Currently, the only treatment available is symptoms management. Novel approximations are trying to treat these patients with gene therapy, namely, using viral vectors. However, these vectors can be recognized by the immune system decreasing their therapeutic activity and making impossible a multidose treatment due to the induction of the humoral immunity following the first dose.
Our objective is to demonstrate the feasibility of using a hybrid vector to avoid immune clearance, based on the electrostatic coating of adeno-associated virus (AAVs) vectors with our proprietary polymers.
We coated model adeno-associated virus vectors by electrostatic interaction of our cationic poly (beta aminoester) polymers with the viral anionic capsid and characterized biophysical properties. Once the nanoformulations were designed, we studied their in vivo biodistribution by bioluminescence analysis and we finally studied the capacity of the polymers as potential coatings to avoid antibody neutralization.
We tested two polymer combinations and we demonstrated the need for poly(ethylene glycol) addition to avoid vector aggregation after coating. In vivo biodistribution studies demonstrated that viral particles are located in the liver (short times) and also in muscles (long times), the target organ. However, we did not achieve complete antibody neutralization shielding using this electrostatic coating.
The null hypothesis stands: although it is feasible to coat viral particles by electrostatic interaction with a proprietary polymer, this strategy is not appropriate for AAVs due to their small size, so other alternatives are required as a novel treatment for DMD patients.
杜氏肌营养不良症（DMD）是最常见的肌肉营养不良症之一，由肌营养不良蛋白基因的突变形式引起。目前，可用的唯一治疗方法是症状管理。新的近似方法试图通过基因治疗来治疗这些患者，即使用病毒载体。然而，这些载体可能会被免疫系统识别，从而降低其治疗活性，并由于首次剂量后体液免疫的诱导，使多剂量治疗变得不可能。
我们的目的是展示使用混合载体来避免免疫清除的可行性，该载体基于腺相关病毒（AAV）载体与我们专有的聚合物的静电涂层。
我们通过我们的阳离子聚（β氨基酯）聚合物与病毒阴离子衣壳的静电相互作用来涂层模型腺相关病毒载体，并对其生物物理特性进行了表征。一旦设计了纳米制剂，我们通过生物发光分析研究了它们的体内分布，最后研究了聚合物作为潜在涂层来避免抗体中和的能力。
我们测试了两种聚合物组合，并证明需要添加聚乙二醇（PEG）以避免涂层后载体聚集。体内分布研究表明，病毒颗粒位于肝脏（短时间）和肌肉（长时间），即靶器官。然而，我们并没有通过这种静电涂层完全实现抗体中和屏蔽。
零假设成立：尽管通过与专有聚合物的静电相互作用来涂层病毒颗粒是可行的，但由于 AAV 尺寸较小，该策略不适合 AAV，因此需要其他替代方案作为 DMD 患者的新型治疗方法。
