ROS-scavenging nanomaterials as emerging tools for bone tissue regeneration: A comprehensive review of recent progress

Bone defects, characterized by a loss of skeletal structure integrity, represent a prevalent clinical challenge affecting millions of patients. While bone autografts and allografts offer potential solutions, limitations, including donor scarcity, immune rejection, anatomical constraints, and complications arising from host comorbidities such as diabetes, often lead to unsatisfactory outcomes. This necessitates the need for alternative treatments. Researchers have identified that reactive oxygen species (ROS) play a crucial role in bone regeneration. Although physiological ROS levels are essential for normal healing, excessive ROS accumulation disrupts the balance between bone formation and resorption, hindering regeneration. Antioxidants can mitigate oxidative stress by scavenging ROS or inhibiting their formation, thereby restoring the equilibrium between bone formation and resorption. Advances in nanotechnology have enabled the development of various ROS-scavenging nanomaterials with enhanced therapeutic efficacy. These nanomaterials either function as delivery platforms for conventional antioxidants or as direct ROS-neutralizing agents through intrinsic redox or enzyme-mimicking properties. This review comprehensively summarizes ROS-scavenging nanomaterials for bone tissue regeneration, focusing on their design strategies, underlying mechanisms, applications, and potential for clinical translation.