Nanotechnology-based drug delivery systems for the treatment of Alzheimer's disease

Abstract

Alzheimer's disease is a neurological disorder that results in cognitive and behavioral impairment. Conventional treatment strategies, such as acetylcholinesterase inhibitor drugs, often fail due to their poor solubility, lower bioavailability, and ineffective ability to cross the blood-brain barrier. Nanotechnological treatment methods, which involve the design, characterization, production, and application of nanoscale drug delivery systems, have been employed to optimize therapeutics. These nanotechnologies include polymeric nanoparticles, solid lipid nanoparticles, nanostructured lipid carriers, microemulsion, nanoemulsion, and liquid crystals. Each of these are promising tools for the delivery of therapeutic devices to the brain via various routes of administration, particularly the intranasal route. The objective of this study is to present a systematic review of nanotechnology-based drug delivery systems for the treatment of Alzheimer's disease.

Keywords: Alzheimer’s disease; liquid crystals; microemulsions; nose-to-brain; polymeric nanoparticles; solid lipid nanocarriers; targeted delivery.

Figure 1

Formation of amyloid plaques (A) and neurofibrillary tangles (B) in the neurons in Alzheimer’s disease. Abbreviations: Aβ, β-amyloid; APP, amyloid precursor protein.

Figure 2

Schematic differences between nanocapsule, nanostructured lipid carrier, polymeric nanoparticle, and solid lipid nanoparticle drug delivery systems.

Figure 3

Schematic representation of types of liposomes and enlarged view of the layers of phospholipids. Abbreviations: GUV, giant unilamellar vesicle; LUV, large unilamellar vesicle; MLV, multilamellar vesicle; SUV, small unilamellar vesicle.

Figure 4

Main pathways for nanosystems to cross the blood–brain barrier to target to brain. Abbreviations: CNS, central nervous system; NCLs, nanostructured lipid carriers; NPs, nanoparticles.

Figure 5

Photograph of microemulsion and nanoemulsion. Note: Enlarged areas show schematics of the size of droplets formed.

Figure 6

Schematic representation of lamellar, hexagonal, and cubic liquid crystal mesophases formed by surfactant molecules’ self-assembly.