高分子量ヒアルロン酸溶液（HA）における架橋型HAと天然型HAの粘弾性特性

Viscoelastic Properties of Cross-linked Hyaluronic Acid (HA) and Natural HA in High-molecular Weight HA Solution

　臨床応用が検討されている架橋型ヒアルロン酸(HA)と国内で臨床応用されている天然型HAを対象に動的粘弾性測定を行い，関節潤滑への効果の検討を目的とした．粘度・粘弾性測定装置を用いて，角周波数を変化させながら測定を行い，粘弾性特性を評価した．関節摺動面間のような往復動すべり運動を考慮した動的粘性率の結果では，天然型高分子量HA溶液が効果的であることが確認された．生体関節のせん断速度のような潤滑作動条件を考慮した場合，架橋型HAよりも分子量が小さい天然型高分子量HA溶液のほうが粘弾性についての優位性が確認された．

　This study aimed to measure viscoelastic properties for the cross-linked hyaluronic acid (HA) and the natural HA, and to examine the clinical effect.　The molecular weight of the cross-linked HA, the high-molecular weight natural HA solution and the low-molecular weight natural HA solution were 6×10⁶, 2.7×10⁶ and 8×10⁵, respectively.　The static viscosity coefficient, the dynamic viscosity coefficient, and the first normal stress difference were measured using a viscoelasticity measuring instrument.　In the result of the dynamic viscosity coefficient in which the sliding velocity between the knee joint surfaces during walking was considered, the high-molecular weight natural HA solution was the most effective.　In addition, Weissenberg effect was confirmed.　Considering the lubricating condition in vivo, the superiority of the high-molecular weight natural HA solution was confirmed in viscoelastic properties to the cross-linked HA.