Abstract: With sodium alginate as raw material and calcium chloride as crosslinker, a hollow hydrogel fiber was fabricated by direct writing combined with crosslinking, and was used to construct tissue engineering scaffold. Fiber gel fraction and swelling degree directly affect the forming quality of scaffold and laden cell survival. The influence of materials concentration on gel fraction was analyzed by leaching the ungelled part from the fiber. As a control group, alginate beads were prepared with coagulating bath. The requirements of direct writing process, such as gel rate, gel fraction and fiber morphology were satisfied, when the concentration of sodium alginate and calcium chloride were 4% and 3% respectively. With increasing sodium alginate's concentration, equilibrium swelling degree of hollow fiber first decreased and then slightly increased and stabilized finally. With increasing calcium chloride's concentration, swelling degree gradually decreased. Due to smaller diffusion interface, swelling degree of hollow fiber was two to five times higher than the gelled beads, and higher moisture was in favor of the viability and mass transfer for cell laden.

Key words: sodium alginate, polymer processing, hollow fiber, leaching, gels, gel fraction, swelling degree

摘要： 以海藻酸钠为原料、氯化钙为交联剂,反应直写制备海藻酸钙水凝胶中空纤维及组织工程支架.纤维的凝胶率和溶胀度直接影响支架的成形质量与所装载细胞的存活率.浸取分离所直写中空纤维的未交联部分,分析材料浓度对凝胶率的影响;以滴注凝固浴制备的海藻酸钙微球为对照组,分析直写工艺的溶胀度表现.结果表明,以4%海藻酸钠与3%氯化钙材料交联直写的中空纤维凝胶率和纤维形貌较好地满足了直写工艺的要求;随着海藻酸钠浓度的增加,中空纤维的溶胀度先减小后小幅升高并趋于稳定;随着氯化钙浓度的增加,凝胶纤维的溶胀度逐渐减小;反应直写工艺由于较小的两相接触表面,其溶胀度比凝固浴制备凝胶微球高2～5倍,更高的含水率有利于保障所装载细胞的活性和传质.

关键词: 海藻酸钠, 聚合物加工, 中空纤维, 浸取, 凝胶, 凝胶率, 溶胀度