Novel calcium-alginate capsules with aqueous core and thermo-responsive membrane

Novel calcium-alginate (Ca-alginate) capsules with aqueous core and thermo-responsive membrane are successfully prepared by introducing a co-extrusion minifluidic approach, and the thermo-responsive gating characteristics of Ca-alginate capsule membranes embedded with poly(N-isopropylacrylamide) (PNIPAM) microspheres are investigated systematically. The experimental results show that the prepared Ca-alginate capsules are highly monodisperse, and the average diameter and membrane thickness of Ca-alginate capsules are about 2.96 mm and 0.11 mm respectively. The Ca-alginate capsule membranes exhibit desired thermo-responsive gating property. With increasing the content of PNIPAM microspheres embedded in the Ca-alginate capsule membranes, the thermo-responsive gating coefficient of the capsule membranes increases simply. When solute molecules diffuse through the capsule membrane, the thermo-responsive gating coefficient is significantly affected by the molecular weight of solute molecules.

Graphical abstractNovel calcium-alginate capsules with aqueous core and thermo-responsive membrane embedded with poly(N-isopropylacrylamide) microspheres are successfully fabricated. The trans-membrane diffusional permeability of solute molecules can be controlled by changing the environmental temperature.Figure optionsDownload full-size imageDownload high-quality image (172 K)Download as PowerPoint slideResearch highlights► Novel calcium-alginate capsules are fabricated with aqueous core and thermo-responsive membrane. ► The thermo-responsive calcium-alginate capsule membranes are embedded with poly(N-isopropylacrylamide) microspheres. ► The trans-membrane diffusional permeability of solute molecules can be controlled by changing the environmental temperature. ► The thermo-responsive gating coefficient of diffusional permeability is significantly affected by the molecular weight of solute molecules.