二乙烯基砜交联透明质酸钠凝胶的制备及其生物相容性

Preparation and biocompatibility of sodium hyaluronate gel cross-linked by divinylsulfone

背景:透明质酸在体内易降解,通过对天然透明质酸进行结构改造和修饰,获得具有更优异的物理化学特性,同时保留透明质酸原有良好生物相容性的透明质酸衍生物。目的:选用二乙烯基砜为交联剂制备交联透明质酸钠凝胶,分析物料比、pH值及温度对交联密度的影响,并观察其在小鼠体内的生物相容性。设计、时间及地点:于2007-03/12在北京泰克美科技有限公司生物医用材料与药物分析实验室完成皮下移植对比观察实验。材料:选择健康KM小鼠40只,制作动物模型。方法:①碱性条件下制备二乙烯基砜交联透明质酸钠凝胶,利用Flory-Rehner公式计算交联点间的平均分子质量—M—c值衡量交联密度。分析物料比、pH值、温度对—M—c值的影响。②KM小鼠背部中线右侧皮下注射0.5mL交联透明质酸钠样品,左侧皮下注射0.5mL对照品,形成圆形皮丘。主要观察指标:注射后5～60d观察二乙烯基砜交联透明质酸钠凝胶的生物相容性和体内降解率。结果:制备体内注射填充用二乙烯基砜交联透明质酸钠凝胶的最优条件为透明质酸和二乙烯基砜物料比为40:1,NaOH为0.200mol/L,温度40℃。KM小鼠皮下注射60d体内降解率为41%,未发现局部刺激反应。结论:改变物料比、pH值及温度条件可以制备不同交联密度的二乙烯基砜交联透明质酸钠凝胶,体内存留实验显示二乙烯基砜交联透明质酸钠凝胶具有良好的生物相容性,具有成为组织充填剂的特性。

BACKGROUND： Hyaluronic acid （HA） is degradable in vivo. Structural reconstruction and modification of natural hyaluronic acid can obtain its derivative with better physical and chemical characteristics, and maitain the original biocompatibility. OBJECTIVE： To evaluate influences of material ratio, pH value and reaction temperature on cross-linking density of sodium hyaluronate gel cross-linked by divinylsulfone （DVS）, and to determine its biocompatibility. DESIGN, TIME AND SETTING： The controlled observation experiment of subcutaneous transplantation was performed at Bio-drug Synthesis and Analysis Laboratory of Beijing Techmate Technology Co., Ltd. from March to December 2007. MATERIALS： Forty healthy KM mice were selected and made into models. METHODS： （1）Sodium hyaluronate cross-linkage gel, made by reaction between hyaluronate and DVS, was prepared under basic condition. Flory-Rehner formula was used to determine the cross-link density of gel by calculating the average molecular weight between crosslinks （Mc）. Influence of material ratio, pH value and reaction temperature on Mc was analyzed. （2）The gel （0.5 mL） was implanted subcutaneously into right side of back median line of KM mice, and 0.5 mL control drug was implanted into left side of mice, which formed round skin cumulus. MAIN OUTCOME MEASURES： Biocompatlbility and in vitro degradation ratio of sodium hyaluronate gel cross-linked by DVS within 5-60 days after injection： RESULTS： The optimum conditions for preparing sodium hyaluronate gel cross-linked by DVS as a injection biomaterial was MHA：MDvs=40：1, CNaOH--0.200 mol/L at 40℃. The degradation ratio in KM mice was 41% in 60 days. No local stimulation was observed in rats. CONCLUSION： Gels with different cross-link densities will be obtained as material ratio, pH value and reaction temperature change. They possess good biocompatibility and may become excellent potentials as implantable biomaterials.