Affiliations: [a] Department of General Medical Sciences, Chiba University, Chiba, Japan | [b] Aginko Research AG, Marly, Switzerland | [c] Université Paris-Est, Ecole Nationale Vétérinaire d’Alfort, Surgery Unit CHUVA, Maisons-Alfort Cedex, France | [d] Fidia Farmaceutici SpA, Abano Terme, Italy
Correspondence:
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Corresponding author: Atsuya Watanabe, M.D., PhD, Professor, Department of General Medical Sciences, Chiba University; Director, Department of Orthopaedic Surgery Eastern Chiba Medical Center, 3-6-2 Okayamadai, Togane, 283-8686, Japan. Tel.: +81 475 50 1199; E-mail: atsuyan1@pa2.so-net.ne.jp
Abstract: BACKGROUND:Various biomaterials/technologies have been tested for treatment of intervertebral disc (IVD) degeneration (IDD). Only few non-surgical options exist. OBJECTIVE:Assessment of efficacy and safety of the hyaluronic acid derivative hydrogel HYADD®4-G in IDD using a well-established rabbit annular puncture model. METHODS:Rabbits were punctured at two IVDs to induce IDD. Thirty days after, IVDs were injected with HYADD®4-G or saline. IVD hydration, height, appearance and tissue organization were assessed by radiographs, MRI and histopathology. Safety of HYADD®4-G injection was evaluated in non-punctured IVDs. RESULTS:HYADD®4-G injection restored disc height to over 75% of the pre-punctured disc, saline injections led to 50% of initial disc height. Compared to saline, HYADD®4-G treatment resulted in improved water retention as revealed by MRI quantification. 83.3% of HYADD®4-G injected discs had normal appearance and reached grade I of the Pfirrmann scale. Regarding tissue organization and cellularity, HYADD®4-G treatment resulted in significantly lower IDD scores than saline (p < 0.01). HYADD®4-G injected into healthy IVDs did not induce inflammation or foreign body reactions. CONCLUSIONS:Intra-discal HYADD®4-G injection is safe and has therapeutic benefits: IDD could be limited through restoration of disc height and hydration and maintenance of normal IVD tissue organization.
