Microparticles and Cell-Laden Hydrogels for Ischemic Stroke imaging and recovery

Current treatments for stroke have a narrow therapeutic window, leaving the survivors with disabilities for life. Although some recovery can be accomplished, the lesion and consequently its impairments will persist[1]. Literature describes the protection of surviving cells and augmentation of self-repair mechanisms as crucial targets for brain repair[2]. Considering this, the current work will focus on the development of cell-laden hydrogels, namely blends of thiolated hyaluronic acid and methacrylated Gellan Gum with Mesenchymal Stem Cells (MSCs), for stroke recovery. The hydrogels will contain Mn²⁺ to evaluate their performance post-injection into the lesion site, by manganese-based MRI. It will be added to the cell-laden hydrogels growth-factor loaded Nanoparticles, for trophic support of transplanted and host cells. These scaffolds will be evaluated in an animal model of stroke, where fast dissolving microparticles (MPs) will be used to produce a stroke-like lesion. The MPs will contain Mn²⁺ and iron-oxide to allow their tracking upon injection.  The MPs were injected through mouse and pig catheter and did not clog while maintaining their shape. The MPs’ MRI signal showed that both Mn²⁺ and iron-oxide are good candidates for MRI contrasts, as even the lowest concentration tested (0.5 mg/mL) produced a signal. Future work will consist in tuning the Mn²⁺ release profile, test the mechanical properties of the hydrogel and their functionality and biocompatibility in vitro, with MSCs cultures.