Evaluating the efficacy of intra-articular polydioxanone (PDO) injections as a novel viscosupplement in osteoarthritis treatment.

Aims: Osteoarthritis (OA) is a chronic joint disorder marked by cartilage breakdown, bone alterations, and inflammation, leading to significant pain and disability. Current therapeutic strategies, ranging from lifestyle interventions to pharmacological and surgical treatments, offer limited efficacy and are often accompanied by side effects. This study investigates the potential of Polydioxanone (PDO), a biocompatible synthetic polymer, as a novel intra-articular (IA) viscosupplement in OA.

Materials And Methods: A validated rabbit model of OA was employed to compare the therapeutic effects of IA injections of PDO against established viscosupplements like hyaluronic acid (HA) and Conjuran (CJR). Sixty rabbits with collagenase-induced OA were randomized into four groups, receiving respective treatments over 12 weeks. The effect of PDO was analyzed by histopathological examination, immunofluorescence staining (IF), immunoblotting, quantitative real-time polymerase chain reaction (qRT-PCR), and enzyme-linked immunosorbent assay (ELISA).

Key Findings: The histopathological examination revealed substantial improvements in the PDO group's cartilage structure and matrix composition. qRT-PCR, IF staining, and Western Blot showed significant downregulation of matrix metalloproteinases (MMPs) and upregulation of type II collagen (COL II) and aggrecan (ACAN). ELISA results corroborated decreased inflammatory mediators- interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) in the PDO-treatment group.

Significance: Preliminary results indicate that PDO may enhance cartilage regeneration and reduce inflammation, suggesting it is a viable and superior treatment option for OA. These findings merit further investigation to translate into clinical applications.