Liposomal Delivery of L‐2‐Hydroxyglutarate for Targeting Epigenetic Dysregulation in Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease characterized by cartilage degradation, inflammation, and dysregulated chondrocyte metabolism. Increasing evidence suggests that epigenetic modifications, particularly alterations in DNA hydroxymethylation regulated by ten‐eleven translocation (TET) enzymes, contribute to OA pathogenesis. Notably, the TET1 inhibitor L‐2‐hydroxyglutarate (L‐2HG) has been reported to mitigate OA‐related changes by modulating 5‐hydroxymethylcytosine (5hmC) levels. However, its efficacy is impaired by rapid intra‐articular clearance, requiring frequent high‐dose administration of the free drug. To address this, we developed a liposomal formulation of L‐2HG (2HG‐LIP) via microfluidic techniques and characterized it in vitro and in preclinical models of OA upon intra‐articular administration. 2HG‐LIP demonstrated favorable physicochemical properties, including homogeneous size (∼150 nm), low polydispersity (∼0.14), high encapsulation efficiency (∼51%), and a suitable release profile. In primary human chondrocytes from healthy and OA donors, 2HG‐LIP exhibited excellent biocompatibility, efficient cellular uptake, and significant downregulation of inflammatory and catabolic genes, such as IL‐1β, IL‐6, MMP‐3, and MMP‐13, upon IL‐1β pro‐inflammatory stimulation. In vivo, a single intra‐articular injection of 2HG‐LIP significantly reduced cartilage damage, MMP‐13 expression, and 5hmC accumulation. Collectively, these findings support 2HG‐LIP as a promising locally delivered epigenetic therapy for OA, with potential for further evaluation in post‐traumatic OA models.