索拉胶-PVA复合水凝胶的制备及其伤口促愈合性能研究

Preparation and wound healing effect of salecan-PVA composite hydrogel

索拉胶是一种水溶性细菌胞外多糖,单一成分的索拉胶水凝胶通常机械性能较差,难以有效应用于伤口敷料领域。采用与其他聚合物共混构建具有互穿聚合物网络的水凝胶可有效改善上述情况。因此,该研究首先利用具有生物粘附特性的聚多巴胺和索拉胶间的静电作用构建第一层凝胶网络;再以聚乙烯醇为另一主要基质进行共混,通过循环冷冻-解冻法构建第二层凝胶网络,从而制备复合水凝胶。通过粘弹性能测试确定水凝胶的最佳制备条件为:索拉胶浓度4%,聚乙烯醇浓度为8%,–20℃冷冻18 h,4℃解冻6 h,冷冻-解冻循环4次。所制备的复合水凝胶内部为分布均匀,高度连续的多孔结构,平衡溶胀率达到41.6%,在5 h内能较好地保证伤口处的湿润环境;其应力、断裂伸长率、断裂能分别为0.21 MPa、117.1%、15.5 J/m。动物实验结果表明该复合水凝胶可有效促进大鼠创面愈合,有望用作伤口敷料。

Salecan is a water-solubility extracellular polysaccharide,but salecan-based hydrogels often exhibit poor mechanical strength,restricting its application as wound dressings.Constructing interpenetrating polymer network hydrogels with other polymers can effectively solve the above problem.Herein,a novel composite hydrogel was prepared as follows:the first network structure between salecan and polydopamine(PDA)was formed through electrostatic interaction,and then polyvinyl alcohol(PVA)was selected to mix with PDA and salecan,the cycle freezing-thawing method was conducted to form the second layer of gel network.The optimal preparation conditions of the composite hydrogel were determined by the viscoelastic test as follows:the concentration of salecan is 4%,the concentration of PVA is 8%,the hydrogel is frozen at-20℃for 18 h,thawed at 4℃for 6 h,and the cycle of freezing-thawing is four times.The hydrogel has a highly continuous porous structure with uniform distribution.The swelling ratio of hydrogel reaches 41.6%,and it could maintain the wound in a moist environment within 5 hours.Its stress can reach 0.21 MPa,elongation at break can reach 117.1%,and fracture energy is 15.5 J/m.The results of animal experiments showed that the prepared hydrogel could effectively promote wound healing in rats,and is expected to be used as a wound dressing.