Using bio-inks provides a high reproducibility and precise control over the fabricated constructs in an automated manner.
Differences from traditional 3D printing materials Bioink compositions and chemistries are often inspired and derived from existing hydrogel biomaterials.
Volumetric bioprinting occurs when a bio-ink is placed in a liquid cell and is selectively irradiated by an energy source.
Important considerations in printability include: Structural bio inks are used to create the framework of the desired print using materials like alginate, decellularized ECM, gelatins, and more.
From the choice of material you are able to control mechanical properties, shape and size, and cell viability.
Channels and open spaces are massively important to allow for cellular migration and nutrient transportation lending them useful if trying to design a vascular network.
In other situations, such as introducing the construct to a bioreactor after printing, these structures can be used to allow for easy interface with systems used to develop the tissue at a faster rate.
Alginates are particularly suitable for bioprinting due to their mild cross-linking conditions via incorporation of divalent ions such as calcium.
Alginate has become the most widely used natural polymer for bioprinting and is most likely the most common material of choice for in vivo studies.
Gellan gum is a hydrophilic and high-molecular weight anionic polysaccharide produced by bacteria.
The melting and gelling temperatures of agarose can be modified chemically, which in turn makes its printability better.
The formation of gelatin scaffolds is dictated by the physical chain entanglements of the material which forms a gel at low temperatures.
A more permanent pluronic-based network can be formed through the modification of the pluronic chain with acrylate groups that may be chemically cross-linked.
Organs such as heart, muscle, cartilage, bone, and fat are decellularized, lyophilized, and pulverized, to create a soluble matrix that can then be formed into gels.
They consist of a complex mixture of ECM structural and decorating proteins specific to their tissue origin, and provide tissue-specific cues to cells.