Pickering emulgels reinforced with host-guest supramolecular inclusion complexes for high fidelity direct ink writing

Direct ink writing (DIW) of Pickering emulsions offers great potential for constructing on-demand objects. However, the rheological properties of fluid emulsions greatly undermines the shape fidelity and structural integrity of 3D-printed structures. We solve here these challenges and realize a new route towards complex constructs for actual deployment. A dynamic, supramolecular host-guest hydrogel based on poly(ethylene glycol) and alpha-cyclodextrin was synthesized in the continuous phase of cellulose nanocrystal-stabilized Pickering emulsions. The storage modulus of the obtained emulgels could reach up to similar to 113 kPa, while being shear thinning and yielding precise printability. Diverse complex architectures were possible with high shape fidelity and structural integrity. The printed objects, for example a double-wall cylinder with 75 layers, demonstrated excellent dimensional stability (shrinkage of 7 +/- 2% after freeze-drying). With the merits of a simple fabrication process and the high biocompatibility of all the components, the concept of dynamic supramolecular hydrogel-reinforced emulgels represent a potentially versatile route to construct new materials and structures via DIW for use in bioproducts and biomedical devices.

Automated summary

This study addresses the challenges of rheological properties in direct ink writing of Pickering emulsions by synthesizing a dynamic supramolecular host-guest hydrogel. The resulting emulgels exhibit high storage modulus, shear thinning behavior, and precise printability, leading to diverse complex architectures with excellent shape fidelity and structural integrity. The concept of dynamic supramolecular hydrogel-reinforced emulgels represents a potentially versatile route for constructing new materials and structures via DIW for bioproducts and biomedical devices.