What are spheroids and why are they important?
Spheroids, the three-dimensional (3D) cell cultures that arrange themselves during proliferation into sphere-like formations, got their name in the 1970s, when scientists observed that hamster lung cells grown in suspension arranged themselves in a nearly perfect spherical form. Unlike two-dimensional, monolayer cell cultures, in which cells interact with the substrate they grow on, 3D cell cultures can grow into spheroids that promote cell–to–cell connectivity and can be embedded in the extracellular matrix (ECM) within native tissue. They help provide a better understanding of cells in their microenvironment and offer a more realistic cellular scenario for research.
Spheroids are especially interesting in regenerative medicine, cancer research and drug screening. Spheroids from mesenchymal stem cells—multipotent cells in bone marrow that have the ability to form and repair skeletal tissues—have shown increased tissue regeneration and repair properties and a longer survival period after transplantation. In cancer research, spheroids are used as multicellular tumor spheroid models (MCTS) to study solid tumor biology. The unique cell composition within an MCTS—how cells grow, interact, proliferate and absorb nutrients and chemical compounds—also makes them ideal preclinical test cultures for drug candidates.
3D bioprinting automation for spheroid formation
Some challenges of spheroid formation are finding the most suitable technique and workflow for generating spheroids that are easily reproducible and uniform in size. Since cellular functions inside spheroids show a close correlation to the size of the spheroid, size uniformity is especially important for getting reproducible results. With improved spatial control, reduction in human error, material flexibility and increased speed, 3D bioprinting automation allows a greater degree of size uniformity and reproducibility. Today’s bioprinters enable the printing of multiple cell types simultaneously and high-precision droplet dispensing. They allow the concurrent use of different types of biomaterials such as hydrogels, biofilms and particles. Scalable, cost-efficient 3D bioprinting systems that can print faster and in larger quantities are poised for further innovation. But just as important, they enable scientists to develop standard workflows, avoid time-consuming and repetitive tasks and gather more consistent data to work on better predictive models for spheroids. Refining the use and efficiency of spheroids that promote cell proliferation and viability will no doubt create paths to new and exciting spheroid applications.
Create spheroids in your lab
Spheroids continue to propel 3D cell culture forward. At CELLINK, we recognize the need for tools that simplify the easy and reproducible formation of these cell clusters. To that end, we have equipped our BIO X™ with a dedicated droplet mode and have developed an Electromagnetic Droplet printhead for fast–pace dispensing. We complement our BIO X 3d bioprinter with technologies like the Spheroid Kit which includes ULA plates and bioinks suited for a variety of cell types. For higher throughput needs, DISPENDIX’s I.DOT™ and I.DOT™ MINI Liquid handling systems offer rapid cell–friendly dispensing methods to users.