[Technical characteristics of Alzheimer model based on organ technology (organoid)]

Alzheimer's disease (AD) is a serious neurodegenerative disorder that manifests itself as progressive damage to memory and knowledge and is the main cause of dementia in the elderly. AD is characterized by extracellular deposition of amyloid-β plate (Aβ) and by the formation of neurofibrillary tangles, composed of hyperphosphorylated Tau protein. These modifications lead to neuronal cell death, vascular dysfunction and inflammatory disorders. Described as "elderly disease", AD is an escalating threat to developed countries as life expectancy is increasing. Because of its severity, AD has been the subject of extensive studies that address the pathogenesis of the disease. However, its main cause remains unknown. Most research on neurological conditions has been applied to animal models. However, due to their high cost and the uncertain translation of their results to humans along with moral concerns, in recent years, there has been a growing need for in vitro modeling to mimic the brain. The creation of the aforementioned models aims at a better understanding of the factors contributing to the onset of the disease and the faster development of the treatment of diseases affecting the nervous system. Given this need, in this review, new approaches to study neurodegenerative disease were recorded. A three-dimensional (3D) neurosphere-based microfluid chip has been reported and this model imitates the in vivo microenvironment of the brain and provides a steady flow of fluid that is observed in the brain's space. Uniform neurospheres, with cell interactions and contacts in all directions, were formed in a hollow microfuge and a steady interstitial flow rate was maintained using a small pump osmotic system. In this model it was possible to control the toxic effects of amyloid-β. At the end, it was observed that the deposition of amyloid-β through an osmotic micro-pump significantly reduced the viability of the neurospheres and caused destruction of the neuronal networks. Therefore, this model was proposed as an in vitro brain model for neurodegenerative disease and high-throughput drugs.