Biofabrication researchers continually strive to improve 3D bio-printed constructs to resemble real tissues better. Unfortunately, there is a lack of fundamental principles that describe how cell-generated forces cause deformations, mechanical instabilities, and structural failures within such constructs.
Researchers of the University of Florida recently investigated the mechanical behaviours of 3D printed microbeams. A microbeam is a narrow beam of radiation, of micrometre dimensions and allows precisely defined quantities of damage to be introduced at precisely defined locations. Microbeams are used as a tool to study intra- and inter-cellular mechanisms of damage signal transduction. To investigate how cell-generated forces collectively drive shape changes in multicellular structures, the team 3D print cell–ECM mixtures into a jammed microgel medium.
The microgel created a mechanically controlled environment that allowed the beams to evolve under cell-generated forces. By varying the properties of the beams and the microgel medium, the team researched buckling, axial contraction, failure, and the total static stability within this structure. Based on their observations, a mechanical model of cell- microbeam mechanics was developed, and simple building blocks of fundamental 3D shapes were envisioned to facilitate a predictable design for future structures.
The team published their findings in the Nature Communications journal under the title: “Quantitative characterization of 3D bioprinted structural elements under cell generated forces“.
Morley, C. D., Ellison, S. T., Bhattacharjee, T., O’Bryan, C. S., Zhang, Y., Smith, K. F., … & Niemi, S. (2019). Quantitative characterization of 3D bioprinted structural elements under cell generated forces. Nature communications, 10(1), 3029.