Strokes occur when the blood supply to specific areas of the brain is interrupted, causing irreparable damage to the tissue. The use of agents such as cyclosporin A (CsA)—which are known to increase the growth and development of neural stem/progenitor cells (NSPCs) capable of repairing damaged brain tissue—has been shown to be a promising therapy for stroke. However, clinical use of this therapeutic strategy is limited because methods to efficiently deliver sufficient doses of CsA to the brain are lacking.
A recent study published by McEwen Centre for Regenerative Medicine Researcher Dr. Molly Shoichet provides a new method for increasing the delivery of CsA to sites of brain injury by using a biodegradable injectable hydrogel.
In the study, Dr. Shoichet and her team used a newly developed hydrogel composed of hyaluronan and methylcellulose (HAMC) that was formulated with CsA microparticles. The team found that using HAMC led to much higher concentrations of CsA in the brain in comparison to other methods tested. Results also showed that while using HAMC alone reduced damage to brain tissue, combining CsA and HAMC had an additional effect: it increased the number of NSPCs in the brain and enhanced their development into neurons.
The dual benefits of this system—which combines the protective effects of HAMC and increased NSPC stimulation through CsA—may provide a safe and effective method for promoting brain repair after a stroke.
This work was supported by the Heart & Stroke Foundation, the Centre for Stroke Recovery, the CIHR Training Program in Regenerative Medicine and the McEwen Centre for Regenerative Medicine. M Shoichet is a Tier 1 Canada Research Chair in Tissue Engineering.
Circumventing the blood-brain barrier: Local delivery of cyclosporin A stimulates stem cells in stroke-injured rat brain. Tuladhar A, Morshead CM, Shoichet MS. J Control Release. 2015 Oct 10. [Abstract]