Nasal Spray to the Rescue of Neurons in Stroke

An Analytical Study on the Mechanism of Grouping of Droplets

The condition for the formation of droplet groups in liquid sprays is poorly understood. This study looks at a simplified model system consisting of two iso-propanol droplets of equal diameter, Dd0, in tandem, separated initially by a center-to-center distance, a20, and moving in the direction of gravity with an initial velocity, Vd0>Vt, where Vt is the terminal velocity of an isolated droplet from Stokes flow analysis. A theoretical analysis based on Stokes flow around this double-droplet system is presented, including an inertial correction factor in terms of drag coefficient to account for large Reynolds numbers (≫1). From this analysis, it is observed that the drag force experienced by the leading droplet is higher than that experienced by the trailing droplet. The temporal evolutions of the velocity, Vd(t), of the droplets, as well as their separation distance, a2(t), are presented, and the time to at which the droplets come in contact with each other and their approach velocity at this time, ΔVd0, are calculated. The effects of the droplet diameter, Dd0, the initial droplet velocity, Vd0, and the initial separation, a20 on to and ΔVd0 are reported. The agreement between the theoretical predictions and experimental data in the literature is good.

Cerebral ischemic stroke and different approaches for treatment of stroke

Background

Cerebral ischemia can be considered a lethal disease as it is a leading cause of death worldwide with no prompt line of treatment. The factors which make this disease more fatal are failure of drugs while crossing BBB, very low availability of the drug in the brain, inefficiency of drug molecule in the clinical studies, limited availability of clinical data, lack of awareness about this disease, and many more.

Main body

This review focuses on reasons and mechanisms of stroke, classification of brain ischemia; it also reveals the current scenario of stroke in India. Very few drugs are effective for the treatment of stroke. This compilation furnishes conventional and recent treatments of stroke along with their hurdles like the gap between preclinical and clinical studies. This review also suggests effective routes of administration of drugs for the treatment of brain ischemia specifically nose-to-brain route and effectiveness of different dosage forms precisely nanoformulations, as the most effective dosage form.

Conclusion

By following different guidelines and treatments, the risk of brain ischemia can be minimized as well as some advanced techniques for the treatment of this disease proving their efficiency. One of the important aspects in the success of the treatment for this disease is the route of administration of the drug. Among all routes, intranasal drug delivery presents a potential approach and is supposed to be the next-generation therapy for brain disorders. The nose-to-brain route is very effective, and it shows some promising results in case of stroke treatment. The strategy is still under investigation despite various successful lab-scale studies; there are numerous challenges to reach the product in the market. Research is going on to get a better understanding of this strategy. We believe that detailed studies to resolve pitfalls will lead to the successful development of an intranasal formulation for the management of ischemic brain injury such as stroke.

IM-12 activates the Wnt-β-catenin signaling pathway and attenuates rtPA-induced hemorrhagic transformation in rats after acute ischemic stroke

Hemorrhagic transformation (HT) is a devastating complication for patients with acute ischemic stroke (AIS) who are treated with tissue plasminogen activator (tPA). HT is associated with high morbidity and mortality, but no effective treatments are currently available to reduce the risk of HT. Therefore, methods to prevent HT are urgently needed. In this study, we used IM-12, an inhibitor of glycogen synthase kinase 3β (GSK-3β), to evaluate the role of the Wnt-β-catenin signaling pathway in recombinant tPA (rtPA)-induced HT. Sprague-Dawley rats were subjected to a middle cerebral artery occlusion (MCAO) model of ischemic stroke, and then were either administered rtPA, rtPA combined with IM-12, or the vehicle at 4 h after stroke was induced. Our results indicate that rats subjected to HT had more severe neurological deficits, brain edema, and blood-brain barrier (BBB) breakdown, and had a greater infarction volume than the control group. Rats treated with IM-12 had improved outcomes compared with those of rats treated with rtPA alone. Moreover, IM-12 increased the protein expression of β-catenin and downstream proteins while suppressing the expression of GSK-3β. These results suggest that IM-12 reduces rtPA-induced HT and attenuates BBB disruption, possibly through activation of the Wnt-β-catenin signaling pathway, and provides a potential therapeutic strategy for preventing tPA-induced HT after AIS.