Hydrogels
A Hydrogel is a network of crosslinked polymer chains that are hydrophilic, sometimes found as a colloidal gel in which water is the dispersion medium. A three-dimensional solid results from the hydrophilic polymer chains being held together by cross-links.

Hydrogels have been used as one of the most common tissue engineering scaffolds over the past two decades due to their ability to maintain a distinct 3D structure, to provide mechanical support for the cells in the engineered tissues, and to simulate the native extracellular matrix.

Bioceramics
Bioceramics are ceramic materials specially developed for use as medical and dental implants. They are usually used to replace hard tissue in the body like bone and teeth.

The following are the techniques for fabricating ceramics:
Foaming Methods
Starch Consolidation Technique
Sponge Replica Method
Solid Freeform Fabrication

Scaffold Fabrication Techniques
Leaching Method
Microsphere Method
Phase Separation Method
Fiber Spinning Method
Decellularized Matrix
3D Printing

3D Bioprinting
3D Bioprinting is a form of additive manufacturing that uses cells and other biocompatible materials as “inks”, also known as Bioinks, to print living structures layer-by-layer which mimic the behavior of natural living systems.

Bioink
Bioink is the material used to produce engineered live tissue using 3D printing technology. It can be composed only of cells, but in most cases, an additional carrier material that envelops the cells is also added. This carrier material is usually a biopolymer gel, which acts as a 3D molecular scaffold.