In Situ Sustained Macrophage-Targeted Nanomicelle-Hydrogel Microspheres for Inhibiting Osteoarthritis

There are stillchallenges in applying drug nanocarriers for in situ sustained macrophage targeting and regulation,due to the rapid clearance of nanocarriers and burst drug release invivo.Herein,a nanomicellehydrogel microsphere,characterized by its macrophage-targeted nanosized secondary structure that allows it to accurately bind to M1 macrophages through active endocytosis,is employed for in situ sustained macrophage targeting and regulation,and addresses the insufficient osteoarthritis therapeutic efficacy caused by rapid clearance of drug nanocarriers.The 3-dimensional structure of a microsphere can prevent the rapid escape and clearance of a nanomicelle,thus keeping it in joints,while the ligand-guided secondary structure can carry drugs to accurately target and enter M1 macrophages,and release drugs via the transition from hydrophobicity to hydrophilicity of nanomicelles under inflammatory stimulation inside the macrophages.