Growth factor delivery for neural tissue engineering

Abstract

The Nervous system (NS) is the complex well-organized cell collection in charge of controlling, coordinating, communicating, and directing all essential functions of our internal organs/body. Anatomically, it consists of two main components: the central nervous system (CNS) and the pe ripheral nervous system (PNS). Functionally, it is subdivided into the so matic nervous system and the autonomic nervous system (visceral) [1]. The CNS is the brain and spinal cord, while the PNS comprises all nerves except the CNS [2]. Disease, trauma, and disorders cause injuries to both the PNS and CNS [3]. However, PNS injuries, which place a great burden on in dividuals and health systems, are seen in more than 100,000 people each year in the USA/Europe, and are caused by different traumas [4]. Although PNS injuries are not life-threatening, they may result in a lifetime loss of function and disfigurement [5,6]. The injuries of CNS caused by physical damage, neurodevelopmental disorders, and chronic neurodegenerative diseases damage brain architecture, resulting in loss of neuronal cell bodies, axons, and glial support [7,8]. Normally, the NS begins to self-regenerate and repair itself almost immediately after an injury. However, neural regeneration in the CNS is restricted due to CNS axons’ limited capability of regeneration in contrast to the regeneration ability in the PNS [9]. Axons in the PNS readily regenerate after an injury [10]. However, in some cases (e.g., large peripheral nerve injuries (PNI) > 1 cm), the regenerative ca pacity of the PNS becomes insufficient without any additional surgical/ therapeutic intervention [11]. Despite the understanding of the biological mechanism of the NS regeneration, repair mechanisms of the nervous tissues still remain a challenging issue [12]. The complex structure and function of the NS make limited regeneration and treatment of neural tissues become more difficult in comparison to other human body tissues. Current therapeutic approaches are unable to fully restore nervous system injuries, and there is still a lack of optimal treatment for perfect and complete functional recovery [13]. Therefore, it’s crucial to develop a biomimetic strategy that can provide optimal morphological, chemical, and biological signals for nerve tissue recovery [1]. Therefore, nanotechnology and nerve tissue engineering (NTE) provide new alternative therapeutic approaches for the effective manner of nerve tissue repair [14].