Since the complex interactions of multiple mechanisms involved in Alzheimer's disease (AD) preclude the monotherapeutic approaches from clinical application, combination therapy has become an attractive strategy for AD treatment. However, to be emphasized, the realization of the edges of combination therapy greatly depends on the reasonable choice of targets and the rational design of combination scheme. Acknowledgedly, amyloid plaques and hyperphosphorylated tau (p-tau) are two main hallmarks in AD with close pathological correlations, implying the hopeful prospect of combined intervention in them for AD treatment. Herein, we developed the nano-combination system, neuron-targeting PEG-PLA nanoparticles (CT-NP) loading two peptide drugs H102, a β-sheet breaker acting on Aβ, and NAP, a microtubule stabilizer acting on p-tau. Compared with free peptide combination, nano-combination system partly aligned the in vivo behaviors of combined peptides and enhanced peptide accumulation in lesion neurons by the guidance of targeting peptide CGN and Tet1, facilitating the therapeutic performance of peptide combination. Further, to maximize the therapeutic potential of nano-combination system, the combination ratio and mode were screened by the quantitative evaluation with combination index and U test, respectively, in vitro and in vivo. The results showed that the separated-loading CT-NP at the combination molar ratio of 2:1 (H102:NAP), CT-NP/H102 + CT-NP/NAP(2:1), generated the strongest synergistic therapeutic effects on Aβ, p-tau and their linkage, and effectually prevented neuroinflammation, reversed the neuronal damage and restored cognitive performance in 3 × Tg-AD transgenic mice. Our studies provide critical data on the effectiveness of nano-combination therapy simultaneously intervening in Aβ and p-tau, confirming the promising application of nano-combination strategy in AD treatment.

由于涉及阿尔茨海默病 (AD) 的多种机制的复杂相互作用排除了临床应用的单一治疗方法，因此联合治疗已成为 AD 治疗的有吸引力的策略。但需要强调的是，联合治疗优势的实现在很大程度上取决于靶点的合理选择和联合方案的合理设计。公认的是，淀粉样斑块和过度磷酸化tau蛋白（p-tau）是AD的两个主要标志，具有密切的病理相关性，这意味着联合干预它们以治疗AD的前景广阔。在此，我们开发了纳米组合系统，神经元靶向 PEG-PLA 纳米粒子 (CT-NP) 装载两种肽药物 H102，一种作用于 Aβ 的 β-折叠破坏剂，和一种作用于 p-tau 的微管稳定剂 NAP。通过靶向肽 CGN 和 Tet1 的引导，结合肽的体内行为和损伤神经元中增强的肽积累，促进肽组合的治疗性能。此外，为了最大限度地发挥纳米组合系统的治疗潜力，分别在体外和体内通过组合指数和 U 检验的定量评价来筛选组合比例和模式. 结果表明，CT-NP/H102 + CT-NP/NAP（2:1）的组合摩尔比为 2:1（H102:NAP）的分离负载 CT-NP 产生了最强的协同治疗效果Aβ、p-tau 及其连接，有效预防神经炎症，逆转 3 × Tg-AD 转基因小鼠的神经元损伤并恢复认知能力。我们的研究提供了纳米联合疗法同时干预 Aβ 和 p-tau 的有效性的关键数据，证实了纳米联合策略在 AD 治疗中的应用前景。