FGF21 and Parkinson disease: Histological analysis revealed that the FGF21‐ and Eda‐loaded OACDP hydrogel effectively exerted neuroprotective effects by preventing the loss of TH in the SNc and striatal regions (≈10‐fold), scavenging ROS to alleviate mitochondrial damage, inhibiting the activation of astrocytes and microglia, and inducing the activation of the AMPK/PGC‐1α axis to regulate mitochondrial function, which are multiple mechanisms underlying the treatment of PD.