3D Printing of Responsive Polyelectrolyte Hydrogels Composed of Sodium Alginate and Chitosan for Drug Delivery via Extrusion 3D Printing

3D printing technology has enabled unprecedented flexibility in the design and manufacturing of complex objects, which can be utilized in a variety of fields including personalized and programmable medicine. The Extrusion 3D Printing technology offers highprecision spatial shape forming ability in larger scale compared to other hydrogel printing methods, such as the DLP photo-polymerization based method, and enables polyelectrolyte hydrogel printing by simultaneous multiple components printing ability. The aim of this study is to evaluate the potential of Extrusion based 3D printing for polyelectrolyte hydrogel printing composed of Chitosan and Sodium Alginate solutions, by the use of a multi-nozzle simultaneous system. Further goals include loading the hydrogel with water- soluble drugs or dispersions and testing their pH-responsive release. The pH-responsiveness of the hydrogel would be the result of pH sensitivity of both Chitosan and Sodium Alginate, as they both possess responsive functional groups: an amino group in Chitosan and a carboxylic group in Sodium Alginate. This property makes both components soluble in water at certain pH ranges and thus suitable for dissolving water soluble drugs and dispersions and for preparation of dyes for 3D printing. Another desirable property for drug delivery applications found in both components is their biocompatibility and bio-degradability, as they are both natural polysaccharides. In this study, Extrusion Printing method is used to fabricate pH-responsive bio-compatible hydrogels and their drug-loading capability is tested.