Finding effective disease‐modifying treatment for Alzheimer's disease remains challenging due to an array of factors contributing to the loss of neural function. The current study demonstrates a new strategy, using multitargeted bioactive nanoparticles to modify the brain microenvironment to achieve therapeutic benefits in a well‐characterized mouse model of Alzheimer's disease. The application of brain‐penetrating manganese dioxide nanoparticles significantly reduces hypoxia, neuroinflammation, and oxidative stress; ultimately reducing levels of amyloid β plaques within the neocortex. Analyses of molecular biomarkers and magnetic resonance imaging‐based functional studies indicate that these effects improve microvessel integrity, cerebral blood flow, and cerebral lymphatic clearance of amyloid β. These changes collectively shift the brain microenvironment toward conditions more favorable to continued neural function as demonstrated by improved cognitive function following treatment. Such multimodal disease‐modifying treatment may bridge critical gaps in the therapeutic treatment of neurodegenerative disease.

Globally, a rising burden of complex diseases takes a heavy toll on human lives and poses substantial clinical and economic challenges. This review covers nanomedicine and nanotechnology-enabled advanced drug delivery systems (DDS) designed to address various unmet medical needs. Key nanomedicine and DDSs, currently employed in the clinic to tackle some of these diseases, are discussed focusing on their versatility in diagnostics, anticancer therapy, and diabetes management. Firsthand experiences from our own laboratory and the work of others are presented to provide insights into strategies to design and optimize nanomedicine-and nanotechnology-enabled DDS for enhancing therapeutic outcomes. Computational analysis is also briefly reviewed as a technology for rational design of controlled release DDS. Further explorations of DDS have illuminated the interplay of physiological barriers and their impact on DDS. It is demonstrated how such delivery systems can overcome these barriers for enhanced therapeutic efficacy and how new perspectives of next-generation DDS can be applied clinically.

BackgroundDeveloping effective disease‐modifying treatment for Alzheimer’s disease (AD) remains a tremendous challenge due to its multifactorial nature involving multiple pathologic signaling pathways in addition to ineffective drug delivery through the blood‐brain barrier (BBB).1 With this in mind our group has developed multifunctional bioreactive nanoparticles (Ab‐TP‐MDNPs), consisting of anti‐amyloid β antibody (Ab) linked to brain‐penetrating terpolymer (TP) and manganese dioxide (MnO2) nanoparticles (MDNPs), that are shown to reduce oxidative stress in AD brains.2 Given the early occurrence of oxidative stress, hypoxia, and vascular dysfunction in AD brains,3,4 we investigated the therapeutic effects of Ab‐TP‐MDNPs on reducing neuroinflammation and vascular dysfunction in an AD mouse model.MethodA transgenic mouse model of AD (TgCRND8 species) and wildtype littermates (WT) were treated with intravenous (i.v.) injection of Ab‐TP‐MDNPs (twice/week, 100 µmol Mn/kg b.w.) or vehicle for 2‐weeks. Oxidative and inflammatory biomarkers were examined using immunohistochemistry and enzyme‐linked immunosorbent assay (ELISA). Vascular function before and after the treatment was studied via high resolution magnetic resonance imaging (MRI). Cerebral blood flow (CBF) was assessed using FAIR (flow‐sensitive alternating inversion recovery) technique. BBB permeability was measured via T1 mapping re‐acquisition prior to and following i.v. injection of gadolinium‐diethylenetriamine penta‐acetate (Gd‐DTPA) at 1.2 mmol/kgResultAb‐TP‐MDNPs treatment significantly decreased inflammatory cytokines and activation of microglia and astrocytes markers (reactive microglia: hippocampus by 69% and cortex by 59%, reactive astrocytes: hippocampus by 32% and cortex by 33%). In addition, Ab‐TP‐MDNPs treatment improved CBF (cortex by 19% and subcortex by 35%) and vessel leakage by 29% in the cortex of AD mouse brains.ConclusionAb‐TP‐MDNPs treatment reduced neuroinflammation and vascular dysfunction in an AD mouse model. These findings suggest a new multimodal strategy for AD treatment and encourage further development of such approach for complex neurologic diseases.Reference:1. Panza F, Lozupone M, Logroscino G, Imbimbo BP. Nature Reviews Neurology. 2019;15(2):73‐88.2. He C, Ahmed T, Abbasi AZ, et al. Nano Today. 2020;35:100965.3. Sweeney MD, Montagne A, Sagare AP, et al. Alzheimer’s & Dementia. 2019;15(1):158‐167.4. Nortley R, Korte N, Izquierdo P, et al. Science. 2019:eaav9518.