Osteoarthritis is a progressive degenerative joint disease with cartilage destruction, subchondral bone changes and chronic inflammation. Current therapies provide only short-term relief without tissue repair. Nanomaterials, such as metal, ceramic, polymer nanoparticles, carbon-based nanoparticles, and composites, have large surface area, tunable properties, and strong biological interactions. They enable the targeted delivery of drugs, pass through the cartilage matrix, protect drugs from degradation and regulate inflammatory and oxidative pathways. Nanocarriers encapsulate DNA, siRNA or mRNA and deliver them to diseased cells, such as chondrocytes or synovial cells, using surface modifications with ligands. Nanocoatings improve the osseointegration of implants and prevent infections. Challenges include safety, biodistribution, large-scale production, and regulatory approval. The article focuses on drug delivery, tissue regeneration and implant engineering.