Injectable Hydrogel Containing Dopamine-Based Nanoparticles and Platelet-Rich Plasma for Relieving Osteoarthritis by Scavenging Reactive Oxygen Species and Polarizing Macrophages.

Insufficient removal of reactive oxygen species (ROS) and macrophage M1/M2 polarization in the joint cavity are key factors in the progression of OA. Recent findings have shown that the combination of polydopamine (PDA) and platelet-rich plasma (PRP) is expected to be a promising strategy to treat OA. In light of the short retention period of nanodots in joints, we employed Poloxamer 407 (P407) and hyaluronic acid (HA) to synthesize a thermo-sensitive hydrogel as an injectable platform (HP, refer to HA@P407). Moreover, PDA@PEG (PP) NPs and PRP were synchronously added in the HP platform, called HPP@PP, to yield the treatment for OA. The multifunctional HPP@PP could effectively suppress the generation of ROS, inhibit ferroptosis, and facilitate M2-type macrophage polarization. This study sheds light on a novel promising option for anti-inflammatory treatment of OA via nanotechnology.