Cells and biomaterials for bioprinting
Tissues and organs are self-organizing systems. During the embryonic maturation process, cells undergo biological self-assembly and self-organization without external influence or guiding structures. [Mironov,2009]. However, in vitro, the cell microenvironment is dramatically simplified or not exist, therefore, cells fused and slowly aggregate in a different manner. In bioprinting, biocompatible scaffolds are usually used as structural support for cells to adhere, proliferate, differentiate, and eventually to form the tissue. Studies showed that arrangement of integrins within a scaffold highly influenced stem cell differentiation [Prowse 2011]. Recapitulating the native environment of a specific tissue type, promote stem cell differentiation towards that lineage. The ability to create 3-D tissue structures that contain various cell types and matrix relies on the integration with compatible biomaterials (scaffold materials) for supporting the cellular components. Most cell printing applications adapt the same biomaterials used in traditional bioengineering with hydrogels are the primary biomaterials for live cell printing [Murphy et al 2013; VIVIAN K. LEE and GUOHAO DAI 2016] because they are biocompatible, having low cytotoxicity and their high water content allows them to acquire a structural similarity to the extracellular matrix [Markstedt et al 2015, Souza 2018].