Synthetic Fungal Melanin Nanoparticles with Excellent Antioxidative Property

Melanin-inspired polymers have been widely used in biomedical applications due to their promising biocompatibility and antioxidant capacity. Although several works focusing on the eumelanin-like biomaterials such as polydopamine nanoparticles (PDA NPs) have been well documented, their free radical scavenging capability usually needed to be tailored and improved for some cases of antioxidative therapy. Herein, a kind of fungal melanin-like, poly-(1,8-dihydroxynaphthalene) nanoparticles (PDHN NPs) with uniform and controllable sizes have been synthesized via a facile ammonium persulfate (APS)-mediated oxidative radical polymerization. These resulting PDHN NPs exhibited excellent stability in water and many organic solutions, which could be used for long-term storage and various biological applications. Moreover, the as-prepared PDHN NPs and PDHN NPs incorporated hydrogels both showed excellent free radical scavenging activity in vitro and in vivo, resulting to the accelerated wound healing behaviors. This study would provide a simple strategy to develop new kinds of melanin-like materials with high stability and excellent antioxidative property for biomedical applications.