Blood-Brain Barrier Disruption and Nanomedicine in Neurodegenerative Disorders

The blood circulation in the nervous system is separated from the brain through an important and highly specialized physiological barrier known as the blood–brain barrier (BBB), which plays a critical function in the maintenance of brain homeostasis through the regulation of passage of substances into and out of the brain. In neurodegenerative conditions characterized by neuroinflammation or brain injury, the normal integrity of the BBB becomes disrupted, leading to aberration in the BBB membrane integrity, resulting in an increased permeability and abnormal barrier function. The distortion of the structural arrangement of the BBB renders it permeable to immune cells, toxins, pathogens, and pro-inflammatory mediators gaining access into the brain, which triggers a cascade of biological activities, such as increased neuroinflammation, oxidative stress, and neuronal damage; this influences the progression of neurodegenerative conditions. Understanding the processes underlying BBB disruption is critical for developing therapeutic strategies to restore BBB integrity and prevent the detrimental consequences of barrier dysfunction in NDs. Some of the processes of BBB distortion include changes in the tight junction proteins, inflammatory mediators, matrix metalloproteinases, and oxidative stress. Elucidating these mechanisms can aid in the spotting of likely therapeutic target site and the invention of interventions to prevent or minimize BBB dysfunction NDs via nanomedicine-based drug docking systems to improve drug transport through the BBB. In summary, disruption of the blood–brain barrier is significant in the pathogenesis of various brain disorders. The knowledge of the underlying mechanisms and developing targeted interventions to restore BBB integrity are essential for improving disease outcomes and facilitating the advancement of effective remedies for brain diseases, resulting in improved treatment outcomes of various neurological conditions.