Controllable Preparation Of Calcium Alginate Hydrogel Hollow Fiber For Its Applications

Calcium-alginate hydrogel hollow microfibers have a potentiality to be utilized in many fields such as drug delivery and tissue engineering.However,it is difficult to be fabricated by the conventional methods,such as electrospinning and molding.Here,a one-step,continuous and controllable process to fabricate calcium-alginate hydrogel hollow microfibers using capillary microfluidics was presented,using sodium alginate and calcium chloride as raw materials with co-axial microfluidic device.And the application of the fiber was explored,and the tensile properties of the fiber were improved.Firstly,sodium alginate was chosen as the external phase and calcium chloride was chosen as the internal phase.The morphology and hollow structure were characterized by optical microscopy and scanning electron microscopy(SEM).The diameters of hollow fibers can be flexibly adjusted by changing the diameter of orifice within the device,or core and sheath flow rates,or concentration of crosslinker with certain range.Secondly,calcium alginate with high biocompatibility,and such fibers also have hollow structure that can be used for encapsulation.The feasibility of encapsulation in such hollow fibers was explored in this paper.L929 fibroblast cells were selected as model cells,and were encapsulated in the hollow fiber by a one-step method.The viability of the cells was observed under a confocal laser scanning microscopy(CLSM)by live-dead staining method.As a result,it was found that the cells with high viability in the fibers had a tendency to grow linearly along the fiber walls.It provided a new idea for the preparation of linear organs or tissues.Finally,the stretch properties of calcium alginate hollow fiber were enhanced becasue the applications of the fibers were limited by its stretch properties.There methods were used to improve this situation,by changing the divalent ions cross-linked with sodium alginate;by adding PEGDA to form double network hydrogel and by adding SiO2 to form composed hydrogel.All methods can improve the stretch properties.The stretch properties can be improved by weaving methods.