Effects of intra‐articular hyaluronic acid associated to Chitlac (arty‐duo®) in a rat knee osteoarthritis modelFrancesca Salamanna Gianluca Giavaresi Annapaola Parrilli Lucia Martini Nicolò Nicoli Aldini Giovanni Abatangelo Antonio Frizziero Milena Fini
Among conventional osteoarthritis (OA) treatments, intra‐articular (i.a) viscosupplementation with hyaluronic acid (HA) is used to restore joint viscoelasticity. However, the rapid clearance and elimination of HA may limit its application. The aim of this study was to verify the improved efficacy of HA within the joint, using a lactose‐modified chitosan (chitlac) as a potentially chondroprotective additive. Four weeks after induction of experimental OA by destabilization of the medial meniscus (DMM), 12‐week‐old Sprague Dawley male rats (n = 30), received once a week, for three weeks, i.a injections of: (i) HA associated to chitlac (ARTY‐DUO®), (ii) HA; and (iii) sodium chloride (NaCl). Five animals for each group were euthanized 4 weeks after the first i.a injection, while the remaining five were euthanized 8 weeks after the first i.a injection. The restoration of physiological joint microenvironment was tested by histology, histomorphometry, immunohistochemistry, and microtomography (micro‐CT). At 4 and even more at 8 weeks, histological analysis showed a significant decrease in OARSI and Mankin scores, with weaker matrix metalloproteinase (MMP)‐3, MMP‐13, and Galectin‐3 in ARTY‐DUO® group versus NaCl and HA groups. A reduction in Galectin‐1 and a stronger Collagen II staining was seen in both ARTY‐DUO® and HA versus NaCl. A reduction in Kreen‐modified score, for synovium inflammation, was observed in the ARTY‐DUO® group. Micro‐CT measurements did not shown significant differences between the groups. The present results show that i.a ARTY‐DUO® injections produce a significant improvement in knee articular cartilage degeneration and synovium inflammation in a rat model of DMM‐induced OA.