AR28

AR28 (also known as AR-28) is a small-molecule inhibitor of glycogen synthase kinase-3 beta (GSK3β) that acts as a potent activator of the canonical Wnt/β-catenin signaling pathway. Initially developed by Arbor Pharmaceuticals, AR28 has been investigated in Phase II clinical trials for the treatment of skin disorders. More recently, AR28 has been studied for its potential in bone regeneration and musculoskeletal healing, including fracture repair and the prevention of instability-induced osteolysis. To enhance its therapeutic efficacy and target bone tissue specifically, researchers have encapsulated AR28 in polymeric nanoparticles functionalized with a tartrate-resistant acid phosphatase (TRAP)-binding peptide (TBP-NP-AR28). This bone-targeted delivery system is preferentially internalized by macrophages at fracture sites, promoting their polarization toward a pro-regenerative M2 phenotype, suppressing glycolytic metabolism, and accelerating bone healing.