Intelligently thermoresponsive flower-like hollow nano-ruthenium system for sustained release of nerve growth factor to inhibit hyperphosphorylation of tau and neuronal damage for the treatment of Alzheimer's disease

Abstract Alzheimer's disease (AD) seriously affects human health and life and lacks effective treatments. The lessons of many clinical trial failures suggest that targeting amyloid beta to treat AD is difficult, and finding new targets is an important direction for AD drug research. The neurofibrillary tangles formed by hyperphosphorylation of tau protein induce the production of cytotoxic reactive oxygen species (ROS) and cause neuronal apoptosis. Therefore, inhibition of hyperphosphorylation of tau protein and reduction of neuronal damage have become promising methods for the treatment of AD. We herein designed a novel nanocomposite with high stability and good biocompatibility by using flower-shaped hollow nano-ruthenium (Ru NPs) as a carrier, loading nerve growth factor (NGF) and sealing with phase change material (PCM). Due to its excellent photothermal effect, under the near-infrared (NIR) irradiation, the nanocomposite could effectively penetrate the blood-brain barrier (BBB) and respond to phase changes in the lesion area, releasing NGF, which inhibited tau hyperphosphorylation, reduced oxidative stress, and more importantly restored nerve damage and maintained neuronal morphology, thereby significantly improving learning and memory in AD mice. Thus, the experimental results indicate that multifunctional nanocomposites may be a promising drug in the treatment of AD.