Design of Smart PEO-PPO-PEO-Magnetic Drug Delivery System for Alzheimer's Diseases Diagnosis and Therapy.

Amyloid-β (Aβ) oligomers are more likely to be the pathogenic agents of Alzheimer's disease. Development of multiple approaches in detection and clearance pathway for Aβ, may eventually lead to diagnosis and treatments of AD. Following this concept, we proposed temperature-responsive magnetic drug delivery system (DDS). This system designed to enhance imaging tool and controlled drug delivery with the aid of conjugated antibodies to amyloid-derived diffusible ligands (anti-ADDLs), which can identify targeted ADDLs. The magnetic cores compose of conjugated Congo red (CR) to maghemite (Fe2O3) (CR-Fe2O3) have shown great advantage as multimodal imaging agents, while superparamagnetic Fe2O3 also possesses the hyperthermia therapy function. Pluronic F127 poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) PEO-PPO-PEO block copolymer known to be stimuli-responsive and show structure changes when subjected to external, temperature and magnetic signals. To form nanocomposites, magnetic cores coated with Pluronic and produce core/shell structure. X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscope (HR-TEM) were used to characterize as-synthesized magnetic nanocomposites (MNCs). Furthermore, Vibrating magnetometer experiments showed that MNCs have higher magnetization value than bare magnetic nanoparticles (MNPs) and are easy to conduct with an external magnetic field. The dependence of hydrodynamic size of MNCs to the temperature showed an increase in temperature corresponds to a decrease in the size. These results confirm that proposed system can be engineered and employed as smart drug delivery system for AD treatment.