Self-Healing Collagen-Based Hydrogel for Brain Injury Therapy

A review: Carrier-based hydrogels containing bioactive molecules and stem cells for ischemic stroke therapy

Ischemic stroke (IS), a cerebrovascular disease, is the leading cause of physical disability and death worldwide. Tissue plasminogen activator (tPA) and thrombectomy are limited by a narrow therapeutic time window. Although strategies such as drug therapies and cellular therapies have been used in preclinical trials, some important issues in clinical translation have not been addressed: low stem cell survival and drug delivery limited by the blood-brain barrier (BBB). Among the therapeutic options currently sought, carrier-based hydrogels hold great promise for the repair and regeneration of neural tissue in the treatment of ischemic stroke. The advantage lies in the ability to deliver drugs and cells to designated parts of the brain in an injectable manner to enhance therapeutic efficacy. Here, this article provides an overview of the use of carrier-based hydrogels in ischemic stroke therapy and focuses on the use of hydrogel scaffolds containing bioactive molecules and stem cells. In addition to this, we provide a more in-depth summary of the composition, physicochemical properties and physiological functions of the materials themselves. Finally, we also outline the prospects and challenges for clinical translation of hydrogel therapy for IS.

Injectable biomaterial shuttles for cell therapy in stroke

Ischemic stroke (IS) is the leading cause of disability and contributes to a significant socio-economic cost in the western world. Brain repair strategies investigated in the pre-clinical models include the delivery of drug or cell-based therapeutics; which is hindered by the complex anatomy and functional organization of the brain. Biomaterials can be instrumental in alleviating some of these challenges by providing a structural support, localization, immunomodulation and/or modulating cellular cross-talk in the brain. This review addresses the significance of and challenges associated with cell therapy in an ischemic brain. This is followed by a detailed insight into the biomaterial-based delivery systems which have been designed to provide sustained trophic factor delivery for endogenous repair and to support transplanted cell survival and integration. A biomaterial intervention uses a multifaceted approach in enhancing the survival and engraftment of cells during transplantation and this has driven them as potential candidates for the treatment of IS. The biological processes that are activated as a response to the biomaterials and how to modulate them is one of the key factors contributing to the success of the biomaterial-based therapeutic approach. Future perspectives highlight the need of a combinative approach of merging the material design with disease biology to fabricate effective biomaterial-based intervention of stroke.