An anti-inflammatory electroconductive hydrogel with self-healing property for the treatment of Parkinson?s disease

Parkinson's disease (PD) is one of the most common neurodegenerative diseases with the characteristics of a progressive loss of dopaminergic neurons. Biomaterials employed in the treatment of PD are challenging and still limited. Herein, we designed and synthesized conductive hydrogels with the self-healing and anti-inflammatory properties from dialdehyde polyurethane (-36 nm) nanocrosslinker, gold nanoparticles (-15 nm), and O-carboxymethyl chitosan under physiological conditions. These hydrogels showed stable crosslinking network, proper conductivity (2-4 mS/cm), small-gauge needle (30G) injectability, and good biodegradability. Furthermore, the hydrogel promoted the proliferation and differentiation of neural stem cells (NSCs) towards neuronal cells. The anti-inflammatory effect and rescue function on inflammatory NSCs (-80%) were also demonstrated in vitro. Animal experiments confirmed that injection of the conductive hydrogel in the brain recovered the motor function of the PD rats, signified by the relief of the spontaneous circling speed and impaired forelimb usage. Histological analyses showed that injection of the conductive hydrogel increased the density of tyrosine hydroxylase positive neurons and fibers, as well as reduced the inflammatory responses. The in vitro and in vivo findings indicate that this conductive, self-healing, and biodegradable hydrogel with anti-inflammatory nanocomponents may serve as a promising vehicle without additional cells or drugs for the treatment of PD.