What is bioprinting?
Bioprinting is a form of 3D printing that uses biological material. Specifically, by distributing cells and substances such as extracellular matrix to mimic tissues or organs, bioprinting lets researchers model complex biological systems. Compared to manual methods for reproducing these structures in vitro, bioprinting is both faster and more reproducible.
Where is bioprinting useful?
To date, bioprinting applications have focused mainly on organoid research and regenerative medicine. By using a bioprinter for generating organoids, the variability associated with manually producing hydrogel domes can be avoided. And, by bioprinting tissues like skin, blood vessels, or bone, researchers can investigate how these might be regenerated in human patients.
What tools are available for bioprinting?
Bioprinting instrumentations falls into four main categories.
Inkjet-based bioprinters use heat or vibration to spray droplets of the biological material on to the surface of the culture vessel. Although relatively inexpensive, they are often incompatible with the high-viscosity liquids needed for generating organoids and tissues.
Laser-assisted bioprinters instead deposit the biological material in layers. They provide high precision and are suitable for more viscous materials, but can risk damaging the cells due to the use of heat.
Extrusion-based bioprinters use pressure to drive the biological material though a nozzle into pre-defined shapes. Because the pressure can easily be adjusted for different viscosity samples, extrusion-based bioprinters are often favored for their flexibility.
Electrospray and electrospinning bioprinters offer the highest precision. But they come at a price and methods must be carefully optimized to avoid causing voltage-related cell damage.
In addition to instrumentation, numerous bioprinting reagents are available - including many that were originally developed for manually producing 3D cell cultures. One of the best-known examples is Corning® Matrigel® matrix, a solubilized basement membrane prep that has been widely used for organoid research. More recently, this has been joined by various sacrificial bioinks for constructing vascularized tissues, creating channels in microfluidic devices, and producing supportive scaffolds for more complex tissue models.
How easy is it to get started with bioprinting?
Bioprinting doesn’t need to be difficult – instrumentation has been developed to overcome many well-recognized problems. For example, the Corning Matribot® Bioprinter was designed for use with temperature-sensitive hydrogels such as Matrigel matrix, which can undergo premature gelation if handled incorrectly. Manually dispensing these types of materials usually involves using multiple ice buckets to keep the hydrogel and any pipette tips chilled.
By incorporating a cooled syringe printhead and a heated printbed for extrusion-based bioprinting, the Matribot Bioprinter ensures that the hydrogel sets only once it reaches the culture vessel. Importantly, the Matribot Bioprinter can easily be placed inside a biological safety cabinet – a key consideration when working with patient-derived samples such as tumor cells.
Factors to consider for bioprinting:
Like any research technique, bioprinting requires optimization. One of the most important factors to consider is the types of cells involved in your particular model system. For example, endothelial cells may require a different extracellular matrix material to muscle cells, whereas other cell types might need a supporting network of fibroblasts or stromal cells.
You’ll also need to think about experimental throughput. If you’re planning to grow brain-derived organoids for studying developmental signaling pathways, a petri dish could be a good choice. But if you’re intending to use liver-derived organoids for high throughput toxicity testing, a 96-well plate might be a better option.
Whatever the aim of your research, cells should have high viabilities from the outset. This means maintaining cultured cells in log phase growth and storing tissue material appropriately upon harvest to prevent unwanted cell death. To learn more about the Corning Matribot, Matrigel matrix, or other bioprinting tools and technologies, contact Corning Life Sciences.
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