Figure 1.

Biomaterials in neural regeneration.

(A) Examples for hydrogels and NGCs used in CNS and PNS regeneration. Hydrogels are developed in CNS regeneration, such as drug-loaded hydrogels, cell-loaded hydrogels, conductive hydrogels, and channeled hydrogels. NGCs are applied in PNS regeneration, including porous NGCs, microgrooved NGCs, sponge-filled NGCs, multichannel NGCs, filaments-filled NGCs, and hydrogel-filled NGCs. (B) The potential strategies of biomaterial scaffolds for regeneration of the CNS and the PNS. Cells or preferably cellular spheroids are prepared using neural- and vascular-related cells. The cells (or cellular spheroids) and growth factors are added into the pre-gel solutions for the preparation of self-healing injectable hydrogel or the fabrication of 3D printed NGC. Self-healing hydrogel can be injected into the injured site of the brain or spinal cord through a long narrow needle for the CNS regeneration. 3D printed NGC can be implanted to bridge a peripheral nerve gap by surgical operation for the PNS regeneration. 3D: Three-dimensional; CNS: central nervous system; NGC: nerve guide conduit; PNS: peripheral nervous system.