Currently, damage to neural tissue is usually permanent and can cause lasting disability in patients. But with a new approach, published in the Journal of Neural Engineering and conducted by the University of Oxford and the Institute of Neural Regeneration & Tissue Engineering, there is a high potential that researchers will be able to complete a method for reconstructing neural tissue at high resolution in three dimensions. This new research embeds scaffolding of patterned nanofibers within three-dimensional (3D) hydrogel structures, promoting neurite outgrowth from neurons in the hydrogel, as the neurites track the nanofiber scaffolding. This tracking was especially effective when the nanofiber scaffold was coated with a special adhesion molecule called laminin.
"Neural stem cells hold incredible potential for restoring damaged cells in the nervous system, and 3D reconstruction of neural tissue is essential for replicating the complex anatomical structure and function of the brain and spinal cord," said Dr. McMurtrey, author of the study and director of the Institute of Neural Regeneration & Tissue Engineering. "So it was thought that the combination of induced neuronal cells with micropatterned biomaterials might enable unique advantages in 3D cultures, and this research showed that not only can neuronal cells be cultured in 3D conformations, but the direction and pattern of neurite outgrowth can be guided and controlled using relatively simple combinations of structural cues and biochemical signaling factors."
The ultimate goal for this method would be replicating more complex structures using a patient's own induced stem cells to reconstruct damaged or diseased sites in the nervous system. These 3D reconstructions can then be used to implant into the damaged areas of neural tissue to help reconstruct specific neuroanatomical structures and integrate with the proper neural circuitry in order to restore function.
In any scientific research, patient safety is a priority. In this published research, the scaffolding and hydrogel materials are biocompatible and biodegradable, and the hydrogels can also help to maintain the microstructure of implanted cells and prevent them from washing away in the cerebrospinal fluid that surrounds the brain and spinal cord. This method can also be used to create site-specific reconstructions of neural tissue, which researchers can use to make models for studying disease mechanisms and developmental processes just by using skin cells that are induced into pluripotent stem cells and into neurons from patients with a variety of diseases and conditions.
As with most research, there are many stages to go through before a method is ready for use on patients. But the ability to engineer neural tissue from stem cells and biomaterials holds great potential for regenerative medicine. In particular, this work may one day help in the restoration of functional neuroanatomical pathways and structures at sites of spinal cord injury, traumatic brain injury, tumor resection, stroke, or neurodegenerative diseases of Parkinson's, Huntington's, Alzheimer's, or amyotrophic lateral sclerosis.