Photo-responsive polydopamine nanoenzyme microneedles with oxidative stress regulation ability for atopic dermatitis treatment

As a common chronic inflammatory skin disease, atopic dermatitis (AD) troubles many people, while its effective therapy is a challenge. Here, we present novel polydopamine (PDA) nanoenzyme integrated near-infrared ray (NIR)-responsive microneedles (MNs) with antioxidant capacity for AD treatment. Such MNs are composed of a hyaluronic acid (HA) backing layer and hyaluronic acid methacrylate (HAMA) tips that are loaded with PDA nanoenzyme. Owing to the photo-thermal conversion capability of PDA nanoenzyme, the MNs can enhance local microcirculatory blood flow, inhibit bacterial growth, and consequently alleviate inflammation and facilitate lesion repair. Besides, the antioxidant properties of PDA nanoparticles could markedly reduce the ROS production in HaCaT cells under conditions of elevated oxidative stress. Based on these features, we have demonstrated that the MNs could effectively realize remission in AD mouse models. Thus, we believe that the proposed NIR-responsive PDA nanoenzyme MNs could serve as a promising therapeutic approach for the treatment and management of clinic AD.