双交联聚乙烯醇/海藻酸钠水凝胶的制备与表征

Preparation and Characterization of Double Crosslinked Polyvinyl Alcohol/Sodium Alginate Hydrogels

以聚乙烯醇(PVA)与海藻酸钠(SA)为原料,利用CaCl2/硼酸溶液进行化学交联,再通过循环冷冻解冻物理交联,制备出PVA/SA水凝胶。分析讨论了水凝胶的交联机理、结构、力学性能、含水率、孔隙率及细胞相容性。红外光谱分析表明,经CaCl2/硼酸溶液交联后,Ca^2+与SA中的-COO^-形成络合,硼酸溶液中B(OH)4^-与PVA交联形成交联结构,循环冷冻解冻促使了复合水凝胶中分子间和分子内氢键的形成。扫描电镜测试表明,PVA/SA水凝胶内部具有丰富的多孔结构,孔径约5~30μm。水凝胶的性能可通过交联剂浓度等进行调控,其中m(PVA)/m(SA)为8∶2,交联剂质量分数为5%时,水凝胶压缩模量和压缩强度分别达到(121.84±3.03)kPa和(636.18±68.71)kPa;含水率和孔隙率分别为83.73%和79.98%。细胞培养结果表明,双交联PVA/SA水凝胶细胞相容性良好。

Polyvinyl alcohol/sodium alginate(PVA/SA)hydrogels were prepared by using PVA and SA as raw material.The PVA/SA hydrogels were chemical crosslinked with calcium chloride/boric acid solution,and physical crosslinked by cyclic freezing and thawing.The cross-linking mechanism,mechanical properties,water content,porosity and cell compatibility of hydrogels were analyzed.FT-IR results show that,after cross-linking with CaCl2/boric acid solution,Ca^2+forms complexation with -COO^- in SA,B(OH)4^- in boric acid solution is crosslinked with PVA,and the cyclic freezing and thawing promote the formation of intermolecular and intramolecular hydrogen bonds in the composite hydrogels.SEM results show that the PVA/SA hydrogels exhibit a porous structure inside with a pore size of about 5~30μm.When the PVA/SA mass ratio is 8∶2 and the crosslinking agent mass fraction is 5%,the compression modulus and compressive strength of hydrogels reach(121.84±3.03)kPa and(636.18±68.71)kPa,respectively.Meanwhile,the water content and porosity reach 83.73%and 79.98%,respectively.The PVA/SA hydrogels show good cytocompatibility based on the results of co-culture with cells.