Polysaccharide-based hydrogels for tissue engineering using 3D printing technique

Abstract

Tissue engineering has been offering the potentials for regenerating tissues and organs. In the field of tissue engineering, design and fabrication of scaffolds are one of the important subjects. Scaffolds act as an extracellular matrix and can interact with cells while regeneration of tissues. Hydrogels are often used as scaffolds for tissue engineering approaches, which can absorb high water content. Hydrogels are usually prepared by crosslinking of polymers. In the case of natural polymer-based hydrogels, they have advantages in terms of biocompatibility and biodegradability, compared with synthetic polymer-based hydrogels. However, natural polymer-based hydrogels inherently show weak mechanical properties, which should be improved for tissue engineering applications. In recent years, 3D printing techniques have been widely used for fabricating functional hydrogel scaffolds. 3D printing enables constructing high-resolution 3D structures with computer-aided design. In this thesis, several strategies were used to enhance the mechanical properties of the polysaccharide-based hydrogels. Various molecular weights of hyaluronate-alginate hybrid polymers were synthesized and added to the hydrogels for improving the stiffness of the hydrogels. Besides, combination of chemical and physical crosslinking was introduced to fabricate stretchable hydrogel. Also, double network hydrogels were formed for the purpose of enhancing stiffness and toughness. The developed hydrogels were utilized as extrusion-based 3D bioinks to construct hydrogel scaffolds with self-healing abilities. Hydrogel scaffolds were applied in tissue engineering approaches for the regeneration of various types of tissues, including cartilage, bone, growth plate, and skin. These researches demonstrate potentials of polysaccharide-based hydrogels for tissue engineering approaches.