Abstract: Viscoelastic hydrogel microparticles are used for repair of tissue defects and injuries or filling and occlusion of anatomical structures. These are administered as a microparticle suspension using a catheter, syringe, steerable catheter tip, or comparable technology into the site, where they can be further stabilized by crosslinking or sealing, or through incorporation of a support or encapsulating structure. Materials and methods for solidifying, stabilizing and sealing these materials can be used that are also biocompatible and easily deployed with catheters in the body. The micron sized interstitial spacing provides a scaffold for ingrowth and migration of cells into the gel matrices.

Abstract: Described are methods for producing tissue constructs, tissue constructs produced by the methods, and their use. The described method of producing a tissue construct comprises providing a granular tissue, depositing one or more filaments on or in the granular tissue, each filament comprising an ink, and gelling or fusing the granular tissue, thereby producing the tissue construct.

Abstract: A printhead for 3D printing may include a first nozzle with a first opening configured for an extrusion of ink on a printing surface. The printhead may further include a second nozzle with a second opening configured for an extrusion of ink on the printing surface, where the first nozzle and the second nozzle are positioned to provide simultaneous extrusion of ink on the printing surface, and where a position of the first opening is independently movable relative to a position of the second opening.