Exploration of biomaterial and stem cell-based strategies for promoting neuronal regeneration and creating engineered 3D in-vitro disease models.

The adult brain can produce only a relatively small number of new neurons, and neurogenesis occurs only in specific brain areas. Post-neuronal injury self-repair is very slow and sometimes does not occur. Therefore, advancements in regenerative therapies play an essential role in recovery from damage. This review focuses on stem cell-based neuronal repair by using biomaterials. We discuss neural tissue damage and the associated mechanisms in neuronal repair, highlighting the role of B cells along with VGLUT1/VGLUT2 (vesicular glutamate transporter 1/2) terminals and glutamate AMPA receptors, IL-1R1 signalling, and ERK/Stat6/MERTK Signalling. Furthermore, it focuses on the types of biomaterials, their characteristics, and mechanisms to overcome neuronal damage repair challenges using modern biomaterial-dependent neuronal tissue engineering techniques. Axonal regeneration can be enhanced by mixing many components (biomaterials, cells, and chemicals) to recover from neural nerve illnesses. Polymers, such as collagen, gelatin, chitosan, alginate, hyaluronan, silk fibroin, poly(L-lactic acid), poly(glycolic acid), polycaprolactone, polyphosphoester, and polyurethane, have been used to aid nerve cell growth. These polymers can be either natural or synthetic. Biomaterials that conduct electricity, such as polypyrrole, polythiophene, and polyaniline, can help neurites grow and make cells more active because they carry electrical impulses that help nerve signal travel. The primary goal of this review is to examine the current methods and uses of brain tissue engineering techniques, which include aspects of stem cell-based 3D in vitro and in vivo models, translational efforts, and challenges in clinical applications.