Chapter 55 – Central Nervous System

Publisher Summary This chapter focuses on tissue engineering strategies, including those based on drug delivery, cell delivery, and physical constructs, all of which are aimed at achieving functional recovery after central nervous system (CNS) injury. The use of drug delivery as a reparative and regenerative strategy after CNS injury is investigated in animal models and clinically. Molecules are delivered systemically and injected locally, the latter to the epidural space, intrathecal space (or into the ventricles), and directly into the cord. The goals of drug delivery in the CNS are to limit degeneration (neuroprotection) and promote regeneration (neuroregeneration). Cell therapy is based on transplanted or host cells either producing the desired therapeutic molecule over a prolonged time to promote endogenous repair or replacing lost tissue that would integrate with the host tissue. There are essentially two methods of cell therapy: cell transplantation, where the cells are derived from autogeneic, allogeneic, or xenogeneic sources, and cell stimulation, where the endogenous cell population is stimulated to promote repair. Physical constructs for tissue therapy in the CNS take the form of scaffolds to support cell growth and, in the spinal cord, tubular scaffolds to assist nerve regeneration. The scaffold might alternatively function solely as a drug delivery system to the surrounding tissue or serve a dual role with cells contained within the scaffold.