Emerging polymeric biomaterials and manufacturing-based tissue engineering approaches for neuro regeneration-A critical review on recent effective approaches

The nervous system is a crucial part of the human body that is damaged by traumatic injury, stroke, and neurodegenerative diseases. Recent studies also have shown that neurodegenerative diseases are associated with a subsequently increased risk of COVID-19-related death. Presently used pharmacological and therapeutic strategies are only the symptomatic treatments that involve the disruption of axonal tracts and are unable to repair and regenerate damaged CNS tissue thereby leading to significant unmet clinical needs involved in neural degeneration. The use of stem cell based regenerative medicine approaches is also limited due to heavy cost, ethical concerns and graft rejection. To address all these limitations, the neural tissue engineering philosophy has been developed that focuses on exploring and developing smart biomaterials for neural tissue repair and regeneration. A scaffold based upon natural and synthetic polymers has meant a very potential role to mimic the extracellular matrix of cells and permit the growth of different types of cells thereby improving the biological behavior in vitro and in vivo effects. They treat neurological disorders without the classic drug delivery limitations. Among these biopolymers, the collagen-based hydrogel is successfully applied conduits for clinical trials that ultimately replicate the native physiological environment of the neural tissues and control cell behavior and favor the regeneration of the damaged nerve tissue. The main objective of this review is to investigate the recent approaches and applications of next-generation polymeric biomaterials useful in the management of neurodegenerative diseases. We also discuss the outlook of the polymeric scaffolds that could pave the way for successful clinical practices.