Injectable biomimetic shellfish macromolecule conductive microcarriers loaded with adipose-derived stem cells for nerve repair in vivo

Abstract In regenerating and repairing the nerve injured by the congenital malformation or trauma, the conundrum of electrical signal transmission between the nerve cells in damaged nerve tissue remains an uncrossable barrier, owing to potential limitations of the tissue in repair. Filling conductive guiding cues into nerve conduits has been effective in stimulating functional nerve recovery. The present study presents a novel porous conductive chitosan/polydopamine (CS/PDA) microcarriers for nerve defect repair were prepared by the self-polymerization properties of mussel-like macromolecule dopamine. The porosity is more than 90%, and the electrical conductivity reaches 7 × 10−4 S/cm. The electrical signal was simulated by electrical stimulation in vitro. Compared with non-conductive microcarriers, conductive ones can effectively promote cell adhesion and proliferation. The conductive microcarriers loaded rat adipose-derived stem cells (rADSCs) were injected into nerve conduits and then transplanted into SD rats, with the autologous and the hollow groups as controls. The results of histology, immunohistochemical staining and gait analysis showed that CS/PDA had a promising ability to repair nerve defects in vivo.