Multiple sclerosis (MS) is an inflammatory disease of the central nervous system (CNS) that is identified by focal lesions of inflammation, axonal loss, and demyelination After the blood-brain barrier damage, peripheral immune cells invade the CNS and co-activated the innate immune system in the CNS. T helper lymphocytes (mostly Th۱ and Th۱۷), cytotoxic T cells, B cells, macrophages, microglia, and the cytokines secreted by them, are recognized as underlying MS pathogenesis. Numerous proinflammatory cytokines are produced throughout the inflammatory process, which can activate the microglial cells; these in turn increase the production of different pro-inflammatory factors, which leads to the symptoms of the disease. The resident CNS Macrophages, also known as Microglia.
Microglia are significant cells in MS immunopathology and have particular roles depending on the location and stage of the disease, some of them promote remyelination through the expression of several specific anti-inflammatory molecules. On the other hand, some of them can damage the myelin sheath by secreting proinflammatory cytokines. Therefore, aiming at microglia for treatment can be one of the main strategies. The strategies can be suppression or protective microglia that make the balance in the immune system, or identification of the factors that participate in the disease process through the microglia itself, such as secretory substances. in a new way, macrophage manipulation may novel opportunities in the treatment and management of MS. Macrophages are attractive targets for drug delivery, seeing high uptake due to their phagocytic nature. Because most drugs do not effectively reach macrophages at therapeutic levels, micro-based drug delivery systems have been widely used for targeting macrophages in treating CNS diseases. In this article, we documented a brief overview of MS pathogenesis, the functions, and phenotypes of microglia, and different methods for the treatment of MS by using microglia as a target