Hyaluronic acid increases tendon derived cell viability and proliferation in vitro: comparative study of two different Hyaluronic acid preparations by molecular weight

Background: Hyaluronic Acid (HA) has been already approved by Food and Drug Administration (FDA) for osteoarthritis (OA), while its use in the treatment of tendinopathy is still debated. The aim of this study was to evaluate the effects of two different HA on human rotator cuff tendon derived cells in terms of cell viability, proliferation and apoptosis. Methods: An in vitro model was developed on human tendon derived cells from rotator cuff tears to study the effects of two different HA preparations: Sinovial HL® (High-Low molecular weight) (MW: 80-100 kDa) and KDa Sinovial Forte SF (MW: 800-1200), at various concentrations. Tendon derived cells morphology was evaluated after 0, 7 and 14 d of culture. Viability and proliferation were analyzed after 0, 24, and 48 h of culture and apoptosis occurrence was assessed after 24 h of culture. Results: All the HAPs tested here increased viability and proliferation, in a dose-dependent manner and they reduced apoptosis at early stages (24 h) compared to control cells (without HAPs). Conclusions: HAPs enhanced viability and proliferation and counteracted apoptosis in tendon derived cells.