Hydrophobic Drug Delivery Platforms Based on Covalent Organic Frameworks for Combined Treatment of Alzheimer’s Disease

Alzheimer's disease (AD) is a complex neurodegenerative disease. The pathogenesis of AD remains incompletely understood. It is characterized by a variety of neuropathological changes, including neuroinflammation, neuronal loss and synaptic damage. Multiple pathological changes make achieving good therapeutic effects with a single drug treatment difficult, and using multiple drugs for combination therapy is currently the most effective method. Currently, the mainstay drugs used for AD treatment are hydrophobic drugs, such as curcumin, donepezil, and resveratrol. Because hydrophobic drugs cannot dissolve in bodily fluids and often aggregate or precipitate, their efficacy is greatly reduced. Therefore, there is an urgent need for a drug carrier that can effectively load and continuously release drugs. However, currently, there are few drug carriers that can achieve efficient co-loading of multiple hydrophobic drugs. Therefore, three of two-dimensional imine covalent organic frameworks (COFs) with different monomers were synthesized through rational design and screening. These three synthesized COFs are simultaneously loaded with curcumin (CUR) and benzofurazan (BZ) to achieve combined therapy. The results indicate that among this series of synthesized COFs, the COF synthesized from 4,4',4″-(1,3,5-Triazine-2,4,6-triyl) trianiline and benzene-1,3,5-tricarboxaldehyde (COF-TB) exhibits optimal hydrophobic drug-loading capacity, enabling effective co-loading of CUR and BZ (BC@COF-TB). After treatment with BC@COF-TB, the cognitive function of 5×FAD mice was significantly improved. The COF platform provides a new way to deliver hydrophobic drugs for AD treatment.