Influence of polar interface on the morphology and degradation performance of calcium alginate gel units

The degradation of the bio-scaffold directly affects its structure, function and survival rate of the loaded cells. Sodium alginate as the raw material and calcium chloride as the cross-linking agent were used to prepare calcium alginate hydrogel bio-scaffold; by changing the ratio of iso-propyl alcohol (IPA) to deionized water (DW) in the crosslinking solvent, coaxial reaction flow interfaces with different polarity conditions were obtained, which affected the aggregation morphology of gel units of calcium alginate gel. The regulation ability of interface polarity on the degradation process of calcium alginate gel was investigated. The results show that the polarity index of the solvent changes from 9.0 to 3.9 with the increase of the proportion of IPA in the crosslinking agent; as the polarity of the interface decreases, the microscopic gel unit of the prepared fiber becomes more orderly; the degradation rate of alginate fibers is slowed down by the ordered and dense morphology of gel units; the mass-loss rate of DW-based fiber scaffold on the fifth day is 91.16% while that of IPA-based fiber scaffold is 73.86%; the denser the gel unit, the lower the swelling degree, and the swelling balance has a retarding effect on the degradation process.