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3D printing is a well-known concept, and it is the ability to use digital instructions to manufacture specific shapes and forms in ceramics, plastics, polymers, metal alloys, and other materials. Bio-printing is a form of 3D printing involving cells and tissues.
Bio-Printed Human Tissue
Bio-printing pioneer Organovo is already working with drug companies to test drugs using the 3D tissues and organs as models upon which to assess a medication’s effects. The company is also working on organ and tissue replacements for patients who require transplants. Today the company can supply supplemental tissue therapies such as tubes, patches, or organoids, but in the future it will have functional organ replacements.
In collaboration with Invetech, Organovo has created the world’s first commercial 3D bioprinter to print human tissues. It is loaded with spheroids containing tens of thousands of cells that are injected onto a water-based bio-paper made from collagen, gelatin or some hydrogel. Layers are added that eventually all fuse together until the bio-paper dissolves in most cases to leave only the connected cells.
3D Printing Approaches
As an outcropping of 3D printing, bio-printing is obviously similar and inter-related with the standard technology. 3D printing on its own is now standard in fields such as machine equipment processing and computer-aided design, or CAD, found in engineering and architecture. To support the needs of such fields, 3D printing uses a variety of approaches from fused deposition modeling (FDM) to electron beam melting (EBM) to stereolithography (SLA) and digital light processing (DLP). The last two are common.
Some of the techniques that fall under 3D printing’s additive manufacturing processes apply to bio-printing, this includes; inkjet (often for use only with collagen and gelatin), selective laser sintering (SLS), fused filament fabrication (FFF), and SLA and DLP that can be used for simple and complex manufacture.
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A difference between standard 3D printing and bio-printing is the degree to which bio-printing is reliant on scaffolding and protocols that necessitate building blocks to support multi-cellular designs.
Organovo recognizes the unique nature of many biological 3D designs and is already trying to support the range of forms. Aspect Biosystems is another company that has the same mission. They states that they enable “rapid printing of macro-scale 3D structures that incorporate intricate micro-level details to generate architecturally and functionally accurate human tissues”.
By allowing the user to program the design of a structure, its material composition and the printing process in software, Aspect’s production gives rise to a variety of potential living entities.
Sophisticated 3D Printing
In the ways described, bio-printing is a sophisticated form of 3D printing, pressuring the manufacturing model to do more and for more life-saving applications.
Aspect describes its capabilities as:
- Developing alternative tissue types (GI, vascular, cardiac) including diseased cells
- Modifying the architecture (arrange cells coaxially or in layers) and tissue stiffness
- Changing cell concentrations
- Adding growth factors, specific proteins, or other compounds
What are the life-saving results of bio-printing to date? Unlike 3D printing that do not always address such life and death situations, although certain exceptions do apply, these results include but are not limited to:
- Using MRI images to create a 3D plastic model of a child’s skull prior to surgery to help the surgeon plan and practice surgery in advance and to consult with during surgery
- Using CT scans to create 3D models of cancerous tumors and surrounding tissues to run liquid through the model to visualize the flow of radiopharmaceuticals
- Printing customized implants, such as a custom external airway splint, to save the life of a child born with tracheobronchomalacia
References and Further Reading
3-Dimensional Bioprinting for Tissue Engineering Applications
3D Printing and 3D Bioprinting - Changing the Healthcare Landscape
New Bioprinting Tech to be Developed by Aspect Biosystems with Seed Funding