Neurorestoration Approach by Biomaterials in Ischemic Stroke

Abstract

BACKGROUND Stroke is one of the most important health problems worldwide. Ischemic stroke (IS) constitutes 85-90% of the casuistry among the types of stroke and is the leading cause of disability in people over 65 years of age worldwide (Ghuman and Modo, 2016). Due to the epidemiological importance and the big socioeconomic expenditure involved, it is priority advance in its prevention, control, and treatment (Kalaria et al., 2016; Benjamin et al., 2017). The ischemic injury is caused by an interruption of blood supply in one or more cerebral blood vessels triggering a set of dynamic processes that affect all brain cells and extracellular matrix (ECM) deteriorating the "glioneurovascular niche" (Boisserand et al., 2016). The pathophysiology of IS lies in the restriction or reduction of the supply of oxygen, glucose, and nutrients in the affected brain area. The ischemic cascade begins while there is arterial obstruction causing accidental cell death of core cells damaging tissue irreversibly. This process is accompanied by events of glutamate excitotoxicity, oxidative stress, and neuroinflammation, which affect the homeostatic functioning of the neurons in the affected tissue. The combination of all of them induces permanent brain lesions (Taylor et al., 2008; Thundyil and Lim, 2015; Thornton et al., 2017). However, there are regions near the nucleus or ischemic penumbra (IP) that have had access to a collateral blood circulation, being able to partially counteract the energy deficit (Fisher and Albers, 2013; Gavaret et al., 2019).

Biosensing surfaces and therapeutic biomaterials for the central nervous system in COVID-19

“…Six hours after the tissue ischemia, there may be several factors that can exacerbate neuronal injury avoiding the activity of recoverable cells tracking their mother, ECM, in motion. There is thus little time for us to refigure the CNS after an ischemic stroke and no time for neurons to recall their previously established functions [ 94 ]. Challenges with cell and cytokine therapies for strokes are poor viability of transplanted cells, uncontrolled cell differentiation, cell engraftment failure, and lack of controlled growth factor delivery [ 95 ].…”

“…Challenges with cell and cytokine therapies for strokes are poor viability of transplanted cells, uncontrolled cell differentiation, cell engraftment failure, and lack of controlled growth factor delivery [ 95 ]. For this, stroke remains the third leading cause of disability in adult people, while many restoration approaches have emerged [ 94 ].

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The Role of Stem Cells in the Therapy of Stroke

“…Presence of poststroke active cell proliferation in ipsilateral subventricular zone was proven unambiguously in humans [ 8 ]. Spontaneous, transient increase in the number of precursor cells begins on day 2 after stroke and reaches a maximum in about 2 weeks, decreasing over the next 3-5 weeks and returning to baseline at about 6 weeks [ 9 , 10 ]. However, some authors report that slightly higher mitotic activity in SVZ persists over the next year [ 11 ].…”

Combination of Stem Cells and Rehabilitation Therapies for Ischemic Stroke

“…Similar to biomaterials, the use of drugs in combination with stem cell transplantation is being investigated as a potential booster for these therapeutic benefits [ 13 , 19 ]. Concomitant administration with drugs and the usage of biomaterials stand as promising adjuvants for stem cell therapies in stroke [ 20 , 21 ]. Nevertheless, more data is needed to determine the best compounds, correct dosage, therapeutic window, and specific patient characteristics required for this treatment to have major success [ 13 , 22 ].…”