Nanomaterials in osteoarthritis therapy: advances in drug delivery, tissue regeneration, and implant engineering.

Osteoarthritis (OA) is a progressive degenerative joint disorder characterised by cartilage destruction, subchondral bone alterations, and chronic inflammation. Existing therapeutic interventions primarily provide short-term relief but fail to repair damaged tissues. Nanotechnology has emerged as a potential solution to these shortcomings by facilitating targeted drug delivery, enhancing tissue regeneration, and improving implant performance. Nanomaterials such as metallic, ceramic, polymeric, carbon-based, and composite nanoparticles possess certain unique properties, including high surface area, tunable properties, and strong biological interactions, which aid cartilage repair, bone regeneration, and controlled release of therapeutics. These nanomaterials can cross thick cartilage matrices, protect drugs from degradation, and regulate inflammatory and oxidative pathways that drive the progression of OA. Additionally, nanocoatings improve implant osseointegration and inhibit infection. Nanocarriers encapsulate DNA, siRNA, mRNA, and other nucleic acids, protecting them from degradation and enabling precise delivery to diseased cells within the joint (e.g., chondrocytes or synovial cells) via surface modifications (e.g., ligands that target the cartilage matrix or specific cell receptors). Although the results are promising, challenges in safety, biodistribution, large-scale production, and regulatory approval remain obstacles to clinical translation. This mini-review primarily focuses on nanomaterial-based drug delivery, regenerative repair, and implant engineering strategies, while briefly discussing emerging nanomaterial-cell interactions where relevant. Nanomaterials have the potential to revolutionize the therapeutic management of osteoarthritis, but continued innovation and interdisciplinary collaboration are necessary to realise this potential.