Current treatments after spinal cord injury: Cell engineering, tissue engineering, and combined therapies

Abstract

Both traumatic and non‐traumatic spinal cord injuries (SCIs) can be categorized as damages done to our central nervous system (CNS). The patients' physical and mental health may suffer greatly because of traumatic SCI. With the widespread use of motor vehicles and increasingly aged population, the occurrence of SCI is more frequent than before, creating a considerable burden to global public health. The regeneration process of the spinal cord is hampered by a series of events that occur following SCI like edema, hemorrhage, formation of cystic cavities, and ischemia. An effective strategy for the treatment of SCI and functional recovery still has not been discovered; however, recent advances have been made in bioengineering fields that therapies based on cells, biomaterials, and biomolecules have proved effective in the repair of the spinal cord. In the light of worldwide importance of treatments for SCI, this article aims to provide a review of recent advances by first introducing the physiology, etiology, epidemiology, and mechanisms of SCI. We then put emphasis on the widely used clinical treatments and bioengineering strategies (cell‐based, biomaterial‐based, and biomolecule‐based) for the functional regeneration of the spinal cord as well as challenges faced by scientists currently. This article provides scientists and clinicians with a comprehensive outlook on the recent advances of preclinical and clinical treatments of SCI, hoping to help them find keys to the functional regeneration of SCI.

Piezoelectric biomaterials for neural tissue engineering

“…53 Ascribed to good flexibility, high water content and cross-linked network structures, hydrogels are expected to be connected with soft neural tissues, realizing soft interaction between human and electronic devices to overcome the mechanical mismatch problem of traditional electronic devices. 54,[64][65][66] More recently, Madden et al discussed the piezoelectric mechanism of piezoelectric F I G U R E 2 Multifunctional BT nanomaterials. (A) Fourier transform infrared spectra (i), transmission electron microscope image (ii), energy dispersive X-ray spectroscopy mapping results (iii, iv) of PMMA@BTNWs.…”

“…Ascribed to good flexibility, high water content and cross‐linked network structures, hydrogels are expected to be connected with soft neural tissues, realizing soft interaction between human and electronic devices to overcome the mechanical mismatch problem of traditional electronic devices 54,64–66 . More recently, Madden et al.…”

Emerging biotechnologies and biomedical engineering technologies for hearing reconstruction

“…92 Recently, scaffolds for guiding neural behaviors have been constructed using various biomaterials to promote nerve regeneration. [93][94][95][96] Hu et al reported a conductive and anisotropic substrate by assembling superaligned carbon-nanotube sheets (SA-CNTs) onto biocompatible GelMA hydrogel (GelMA-ACNT) (Figure 8A). 97 The composite substrate inherited the conductivity and topological morphology of SA-CNTs and the good cytocompatibility of GelMA hydrogel.…”

“…The apoptosis and degeneration of SGNs can directly lead to the impairment of the auditory pathway, resulting in serious hearing disorders, and the directed regeneration of SGNs has exhibited promise in the treatment of hearing loss 92 . Recently, scaffolds for guiding neural behaviors have been constructed using various biomaterials to promote nerve regeneration 93–96 . Hu et al.…”

Design and synthesis of nano-biomaterials based on graphene and local delivery of cerebrolysin into the injured spinal cord of mice, promising neural restoration

“…Still, almost three million people worldwide suffer from SCI, with tragic personal and social consequences and high financial costs (more than four billion dollars annually). 1–3 Cascade interactions such as cystic cavitation, generation of glial scar, and the aggregation of inhibitors associated with myelin appear in the SCI lesion site microenvironment during the acute process. 4 By completing the process of glial scar formation, functional nerve recovery leads to failure in nervous tissue regeneration and movement restoration.…”